Fluorescent Up-converting Nanoparticles: a Platform for ...nanoge.org/.../docs/BookAbstractsFUN-Bioenergy14.pdf · Lanthanide doped nanoparticles have the ability to undergo upconversion

Fluorescent Up-converting Nanoparticles: a Platform for Energy and Biomedical Applications Conference - Torremolinos 2014

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International Conference on Fluorescent Up-converting Nanoparticles: a Platform for Energy and Biomedical Applications

Torremolinos, Spain, 4th to 6th June 2014

edited by

Betriz Julián

Universitat Jaume I, Spain

You are cordially invited to participate in the International Conference on Fluorescent Up-converting Nanoparticles: a Platform for Energy and Biomedical Applications, which will be held from June 4th to 6th, 2014 in Torremolinos, Spain. Up-converting nanoparticles (UCNs) constitute an emerging class of luminescent nanomaterials with the ability to efficiently up-convert NIR photons into shorter wavelength radiation. These materials have opened new possibilities in many research fields such as photonics, photovoltaics, sensing and biomedical applications. Probably, among them, the most fascinating advances have been carried out in the fields of Energy and Biomedicine. The growing demand for energy on the global scale requires the development of renewable sources. Solar energy and hydrogen economy have enormous potential for fulfilling the urgent request. The integration of UCNs in photovoltaic and photoelectrochemical devices allows the exploitation of infrared radiation through energy conversion to develop more efficient technologies.

UC nanoparticles have also been studied for a wide range of biomedical applications such as bio-detection, cancer therapy, bio-labeling, fluorescence imaging, nanothermometry, magnetic resonance imaging and drug delivery. They exhibit many advantages over conventional fluorophores, such as high signal-to-noise ratio, superior photostability, deep tissue penetration and low photodamage to biological samples. In the last years, with the advances in nanoparticles synthesis and modification technology, much research has been performed to exploit UCNs’ advantages and integrate them into various biological applications.

International Conference on Fluorescent Up-Converting Nanoparticles: a Platform for

Energy and Biomedical Applications (FUN-Bioenergy14), Torremolinos, Spain

Scientific Committee

Joan J. Carvajal University Rovira i Virgili, Spain

Rute A. S. Ferreira University of Aveiro, Portugal

Jordi Hernando Autonomous University of Barcelona, Spain

Daniel Jaque University of Madrid, Spain

Beatriz Julián Universitat Jaume I, Spain

Jose García Solé University of Madrid, Spain

International Conference on Fluorescent Up-Converting Nanoparticles: a Platform for Energy and Biomedical Applications (FUN-Bioenergy14), Torremolinos, Spain

Invited Speakers

Artur Bednarkiewicz Polish Academy of Sciences, Poland

Marco Bettinelli Verona University, Italy

John. A. Capobianco Concordia University, Canada

Carlos Jacinto Universidade Federal de Alagoas, Brazil

Victor Lavin Universidad de La Laguna

Emma Martín Universidad Autónoma de Madrid

Andries Meijerink Utrecht University, The Netherlands

Cinta Pujol Rovira i Virgili University, Spain

Sidney J. L. Ribeiro São Paulo State University, Brazil


Adolfo Speghini Verona University, Italy

Fiorenzo Vetrone Université du Québec, Canada

Thursday 5th June 9.10 - 9.40 Near Infra-red Trigerred Photodynamic Therapy, Photoswitching and Photostimulated Emission

John Capobianco Concordia University, 7141 Dherbrooke St. West, Montreal, CA

Lanthanide doped nanoparticles have the ability to undergo upconversion. Upconversion is a non-linear anti-Stokes process that efficiently converts two or more low-energy excitation photons, which are generally near infrared (NIR) light, into a higher energy photon (e.g., NIR, visible, ultraviolet) through the use of long lifetime and real ladder-like energy levels of trivalent lanthanide ions embedded in an appropriate inorganic host lattice. Thus, these materials are quickly emerging as candidates in novel biological applications. This stems from their unique optical and chemical properties, such as non-blinking, non-photobleaching, absence of autofluorescence, low-toxicity, low photodamage to live cells, and their remarkable ability to penetrate light in tissues. Here, we present the synthesis, characterization and optical properties of lanthanide-doped fluoride nanoparticles and subsequent strategies to impart biological functionality. Finally, we show relevant biological applications of these upconverting nanoparticles as a platform for photodynamic therapy, photoswitching for drug delivery and bio-imaging using photostimulated emission.

Thursday 5th June 9.40 - 10.10 Upconverting Nanoparticles: Towards a Multifunctional Platform

Fiorenzo Vetrone Institut National de la Recherche Scientifique - Énergie, Matériaux et Télécommunications, Université du Québec, 1650 Boul. Lionel-Boulet, Varennes (Montreal), J3X 1S2, CA

Multiphoton excited nanomaterials are emerging as useful tools in diagnostic medicine and therapeutics. The advantage of these nanomaterials for applications in biology is that they are excited with near-infrared (NIR) light, which mitigates some of the drawbacks associated with the use of UV as the excitation source. NIR light is silent to tissues thus minimizing autofluorescence, possesses greater tissue penetration capabilities and does not incur damage to the sample. However, many of these “typical” multiphoton excited nanomaterials require femtosecond (fs) excitation light to induce the multiphoton excited luminescence.

It is in this regard that there has been an ever-increasing interest in lanthanide (Ln3+

)-doped upconverting nanoparticles as an alternative to more common multiphoton excited nanomaterials. With upconverting nanoparticles, it is possible to obtain UV/visible/NIR emissions using a single NIR excitation source (typically 980 nm) via a process known as upconversion. This multiphoton excitation process differs from what occurs in conventional multiphoton excited materials where the absorption of photons is simultaneous. In the case of Ln

3+-doped materials, the multitude of long-lived “real”

electronic energy states of the Ln3+

ions (from the partially filled 4f shell) allow for sequential absorption of multiple NIR photons eliminating the need for complex and expensive optical excitation. Thus, upconverted luminescence can be observed using an inexpensive commercial continuous wave diode laser.

Here, we present the synthesis and surface functionalization of Ln3+

-doped upconverting nanoparticles and demonstrate how they can be used in biological applications. Furthermore, we will show how these upconverting nanoparticles can be used as building blocks towards developing a multifunctional nanoplatform for the potential diagnostics and therapeutics of diseases such as cancer.

Thursday 5th June 10.10 - 10.40 Lanthanide Doped CAF2 Nanoparticles: Biocompatible, Multifuncional Materials for Biomedical Imaging

Irene Cantarellia, Marco Pedroni

a, Fabio Piccinelli

a, Giamaica Conti

b, Andrea Sbarbati

b, Laura Marongiu

c,

Marta Doninic, Stefano Dusi

c, Federico Boschi

d, Pasquina Marzola

d, Adolfo Speghini

a


a, Dipartimento di Biotecnologie, Università di Verona and INSTM, UdR Verona, Strada Le Grazie 15, Verona, 37134, IT b, Dipartimento di Scienze Neurologiche e del Movimento, Università di Verona, Strada le Grazie 8, 37134, Verona, IT c, Dipartimento di Patologia e Diagnostica, Università di Verona, Strada le Grazie 8, 37134, Verona, IT d, Dipartimento di Informatica, Università di Verona and INSTM, UdR Verona, Strada le Grazie 15, 37134, Verona, IT

Lanthanide doped fluorides are very interesting hosts for their efficient luminescence in the visible and infrared regions, making them interesting for their use in technological applications, such as in biomedical diagnostics. Specifically, Er

3+/Yb

3+ and Tm

3+/Yb

3+ doped MF2 (M=Ca, Sr) nanoparticles have

received attention very recently, due to their strong upconversion emissions. A facile hydrothermal one-step procedure was used to prepare citrate capped triply doped with Er

3+,

Gd3+

and Yb3+

or Tm3+

, Gd3+

and Yb3+

ions. The present nanoparticles are easily dispersible in saline solutions, essential property for their potential use in biological fluids. The obtained nanoparticles are cubic phase and are well size monodispersed, with average sizes that can be easily tuned by changing the preparation conditions.

The obtained transparent colloidal dispersione show strong upconversion emission in the red (around 650 nm) and in the NIR (around 800 nm) for the Er

3+ and Tm

3+ doped nanoparticles,

respectively, upon laser excitation at 980 nm in the2F5/2 level of Yb

3+ ion. Both the excitation and emitted

radiation are close to or inside the biological window, suggesting the possibile use of the nanoparticles for in-vitro and in-vivo biological optical imaging.

Results of spin-echo measurements on saline colloidal dispersions of the nanoparticles have also shown significant proton relaxivities, indicating that the present nanoparticles are interesting MRI contrast agents.

Considering also the high biocompatibility, the present nanoparticles are suitable candidates to be efficiently used as nanoprobes for both in-vitro and in-vivo multimodal optical and magnetic resonance imaging.

Thursday 5th June 11.30 - 12.00 From One- to Three-Photon Fluorescence Nanothermometry, Hyperthermia, and Imaging based on Lanthanide doped Nanomaterials.

Carlos Jacinto Grupo de Fotônica e Fluidos Complexos, Instituto de Física, Universidade Federal de Alagoas, Maceió-AL, Brazil

Over the last few years, the scientific community has invested a lot of effort to develop highly sensitive fluorescence nanomaterials for the most diverse applications such as nanothermometry, bio-imaging, display, biolable, etc. It is known that cellular events are marked basically by changes in temperature and also that two photon fluorescence nanothermometer (FNThM) has been indicated as a more efficient system for highly penetrating fluorescence bio-imaging in comparison to one photon system. But, is this a law? Not, we demonstrate that the emission by one photon could present better deep-penetration. In fact, thermal sensing at the micro- and nano-scales are required for high spatial resolution of temperature gradients and is an indispensible tool for dynamical studies of diverse small systems including electrical, magnetic, photonic, and biological ones. In these “nanothermometers”, the thermal sensing method relies upon the particular parameter that displays a temperature dependence, which gives rise to high resolution thermal imaging techniques, such as thermal coupled levels, spectral shift, polarization, etc. Indeed luminescent nanoparticles have become an important tool mainly in medical applications because of its ability to detection and treatment of human diseases, especially for cancers. Because of the, in general, nonhomogenous distribution of concentration, the best system is that one presenting independence on the concentration. In the present talk, we preset a review of the recent results about one-, two, and three-photon lanthanide doped fluorescence nanothermometry. The potential of the investigated system for bioimaging and hyperthermia are also discussed. Thursday 5th June 12.00 - 12.30 Optical nanothermometry properties of Er3+ ions in Y3Ga5O12 nanogarnet


Sergio Fabián León-Luisa, b

, Virginia Monteseguroa, b

, Mónica L. Fanarragac, Ulises Ruymán Rodríguez-

Mendozaa, b

, Jesús Gonzálezb, d

, Inés Temiñoe, Rafael Valiente

b, e, Vemula Venkatramu

f, Víctor Lavín

a, b

a, Universidad de La Laguna, Departamento de Física, San Cristóbal de La Laguna, 38207, ES b, MALTA Consolider Team, , ES c, Universidad de Cantabria-IDIVAL, Departamento de Biología Molecular, Santander, 39011, ES d, Universidad de Cantabria, CITIMAC, 39005 Santander, ES e, Universidad de Cantabria, Departamento de Física Aplicada, 39005 Santander, ES f, Yogi Vemana University, Department of Physics, 516003 Kadapa, IN

High efficient fluorescent Er3+-doped Y3Ga5O12 (YGG) nanogarnets, with crystalline sizes ranging from 40 to 60 nm, have been synthetized by a sol-gel method and their optical properties have been characterized in order to explore their potential bioimaging applications as temperature nano-sensor. Nanothermometry is especially important in biomedicine and can help extracting knowledge of the local dynamics and performance of the majority of biological microorganism (cell, bacteria,…) that are strongly determined by temperature, and whose sizes are larger than the nanoparticles. Moreover, they can be used in in vivo and in vitro biomedical applications, where the rare earth doped nanoparticles are used as nanothermometers, playing a key role in the control of hyperthermia processes induced either by alternated magnetic fields or by light. In this sense, the rare earth doped inorganic nanoparticles have the advantages of better biologic compatibility and smaller cytotoxicity compared with quantum dots, and they do not need further functionalization to enter into the cells. Optical nanothermometers are calibrated using different parameters (lifetime, polarization, bandwidth, etc.); however, the most widely used is the relative intensities of the emissions from two thermalized states. In this work, we analyze the temperature dependence of green emissions of Er3+ ions in a YGG nanogarnet for its use as optical temperature nanosensors. The green luminescence can be obtained either by de-excitation processes from high energy levels, excited by a blue laser, to the 2H11/2,4S3/2 thermalizing levels or by upconversion processes induced by infrared laser excitation, through the therapeutic window. The photoluminescence and thermal sensitivity together with their application in cells assays are also analyzed in detail.

Thursday 5th June 12.30 - 12.50 Hollow Gold Nanospheres for Photothermal Therapy

Mariano J García-Soto b, Roberto Guzmán

b, Karla Santacruz-Gomez

c, Marcelino Barboza-Flores

c, Mariano

Pedroza-Monteroc, Laura Martinez Maestro

a, Ana Rodriguez Quiros

a, José García Solé

a, Daniel Jaque

a

a, Universidad Autonoma de Madrid, Universidad Autónoma de Madrid, 28049 Madrid, Spain , SPAIN b, The University of Arizona. , The University of Arizona. Tucson, AZ 85721., USA c, Universidad de Sonora. , Blvd. Luis Encinas y Rosales s/n. C.P. 83000, Hermosillo, Sonora, MX., MEXICO

Gold nanoparticles of different sizes and shapes have been successfully used for multiphoton fluorescence imaging. Due its low emission efficiency (multiphoton excitation) these nanoparticles are particularly suitable for photothermal therapy. For real in vivo applications these nanoheaters must be designed with their plasmonic absorption bands matching the biological windows (700-1400 nm). This spectral requirement prevents the use of solid gold nanospheres as useful photothermal agents, as their plasmon resonances can only be tuned up to the visible spectral region by varying its size. Indeed, rod shaped gold nanoparticles (Gold Nano Rods, GNRs), with plasmon resonance around 800 nm have been reported to be one of the most suitable nanoheaters for real in vivo photothermal therapy

1. However,

the non-spherical shape of the nanoparticles difficulties their cellular uptake and it has aimed to search for novel spherical gold nanostructures with plasmon resonances around 800 nm. In this work we have synthesized nearly monodisperse hollow gold nanospheres (HGNSs) and characterized them as nanoheaters operating under laser excitation in the biological window. The hollow interior of these gold nanoparticles provides the possible additional advantage of drug incorporation and so potentiality for drug delivery. The plasmonic extinction band of HGNSs is much broader than the longitudinal plasmon extinction band of GNRs at similar plasmon resonance, thus giving a better chance for tunability in respect to GNRs. First ex vivo photothermal experiments carried out on chicken breast and pork tissues have shown the capability of HGNSs for photothermal therapy. Experiments to determine the light to heat efficiency are under way and will be presented during the conference time.


Thursday 5th June 15.00 - 15.30 Biocellulose-YVO4:Er3+-Ho3+ Nanoparticles Composite Membranes. Infrared to Visible Up-conversion and Activation of PDT Processes

Sidney J.L. Ribeiroa, Karina Nigoghossian

a, Maristela F.S. Peres

b, Fernando L. Primo

b, Antonio C.

Tedescob, Edison Pecoraro

a

a, Institute of Chemistry- São Paulo State Univ, Unesp- CP 355, Araraquara, SP, 14801-970 , Brazil b, Center for Nanotechnology and Tissue Engineering, Photobiology & Photomedicine Research Group, São Paulo University-FFCLRP-DQ, Ribeirão Preto, SP, 14040-901, Brazil

YVO4:(Yb3+

-Er3+

/Ho3+

) nanoparticles (NPs) were incorporated in bacterial cellulose membranes obtained from Gluconacetobacter xylinus. Materials present the property of converting near-infrared (NIR) into higher-energy visible light. NPs were prepared by optimizing towards higher emission intensity at the wavelength range of absorption of Chloroaluminum phthalocyanine (ClAlPc) used as photosensitizer in Photodynamic Therapy. The NIR excitation wavelength is advantageous for application in biological systems, as it allows deeper penetration into tissues than the UV-visible radiation commonly used for luminescence excitation. Upconversion emission spectra obtained under excitation at 980 nm showed preferential green emission for the Yb

3+-Er

3+ system and red emission for

the Yb3+

-Ho3+

one. In the last case, by using mixtures of aqueous suspensions of the nanoparticles and ethanolic solutions of ClAlPc the red emission (680nm) of the phtalocyanine was observed through excitation by the upconverted emission of the nanoparticles (650nm) which were excited in NIR (980nm).

Thursday 5th June 15.30 - 15.50 Triggering the Photochemistry of Anticancer Metal Complexes Using Upconversion Nanoparticles

Emmanuel Ruggieroa, Silvia Alonso de Castro

a, Abraha Habtemariam

a, b, c, Juan C. Mareque-Rivas

a, b, Luca

Salassaa

a, CIC biomaGUNE, Paseo Miramon 182, Donostia, 20009, ES b, IKERBASQUE, Basque Foundation for Science, Bilbao, 48011, ES c, Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK

Transition metal complexes have unique photophysical and photochemical properties which have been explored for many applications including medicinal chemistry and biology. Several metal complexes displaying light-triggered biological activity have been recently reported and show potential as agents for photodynamic therapy.

1 Nevertheless, metal complexes are typically characterized by low

extinction coefficients in the 600–1000 nm region, posing a major limitation for their development as practical clinical tools.

Optically active nanoparticles can be employed as an effective tool to extend the range of excitation wavelengths for metal complexes and overcome such fundamental drawback.

2

Our recent research focuses on the use of upconversion nanoparticles (UCNPs) for the photoactivation of anticancer complexes (e.g. Pt, Ru). UCNPs based of a NaYF4 lattice doped with lanthanides ions (e.g. Yb, Er, Tm) can efficiently convert 980-nm light to higher energies in the ultraviolet and visible region, hence allowing to trigger the photochemistry of metal complexes

3 and potentially

their biological effects. Such approach is promising not only because the NIR light used to excite UCNPs penetrates deeper into tissues, but also because UCNPs have outstanding features as multimodal imaging tools.

In this contribution we will discuss our advances in this new and promising field.

Thursday 5th June 15.50 - 16.10 NIR Excitation of New Upconversion-Photosensitizer Nanohybrids Induces Oxygen-Mediated Cancer Cell Death

María González-Béjara, Marta Liras

b, Laura Francés-Soriano

a, Valerio Voliani

a, Vicente Herranz-Pérez

c, d,

Maria Duran-Morenoc, d

, Jose M. Garcia-Verdugoc, d

, Emilio I. Alarconb, Juan C. Scaiano

a, b, Julia Pérez-

Prietoa


a, Universidad de Valencia, C/ Catedrático José Beltrán, 2, Valencia, 46980, ES b, Department of Chemistry and Centre for Catalysis Research and Innovation , 10, Marie Curie, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada c, Laboratorio de Neurobiología Comparada, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, C/ Catedrático José Beltrán, 2, 46980 Paterna, Universidad de Valencia, CIBERNED, Valencia, ES d, Unidad mixta de Esclerosis múltiple y neurorregeneración, IIS Hospital La Fe, Valencia, ES

Photodynamic therapy (PDT) is a non-invasive cancer treatment that after selective delivery/administration of a photosensitizer (PS) uses light as an activator to produce reactive oxygen species for sequential cancer eradication. Multifunctional nanosystems that integrate multiple materials with different properties can provide new opportunities for simultaneous diagnosis and therapy of diseases. In this regard, the search for efficient PDT-PS/nanomaterial nanohybrids has been encouraging research in the last decade.

Several methods to make water-dispersible NaYF4:Er3+,

Yb3+

up-conversion nanoparticles (UCNPs) loaded with singlet oxygen photosensitizers have recently been reported.

1 The drawbacks of some of

these systems are the low PS payload and/or its leaching under experimental conditions. We present here the preparation of water-dispersible nanohybrids (ca. 30 nm) containing

NaYF4:Er3+,

Yb3+

up-conversion nanoparticles (UCNPs), capped with a polymer and highly-loaded with a non-commercial singlet oxygen photosensitizer. Our novel strategy to load the photosensitizer allowed for an effective energy transfer and, additionally, avoided photosensitizer leaching from the nanohybrid. The effectiveness of the nanohybrids for generating singlet oxygen after near-infrared (NIR) excitation (975 nm) with a continuous wavelength (CW) laser was evidenced by using a probe molecule. In vitro assays demonstrated that the nanohybrid was taken up by the human neuroblastoma-derived cells showing low cytotoxicity. Moreover, ca. 50% cancer cell death was observed after NIR irradiation (45 min, 239mW).

Thursday 5th June 16.10 - 16.30 Synthesis and Characterization of Micro- and Nano-Materials with Different Structures Loaded with Upconverting Molecules

G. Massaroa, b

, C. Roscinib, c

, D.R. Molinab, c

, L. Latterinia

a, Dipartimento di Chimica and Centro Eccellenza Materiali Innovativi Nanostrutturati (CEMIN), Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy b, Institut Català de Nanociència i Nanotecnologia (ICN2), Edifici ICN2, Campus UAB, 08193, Cerdanyola del Vallès, Spain c, Consejo Superior de Investigaciones Cientificas (CSIC), , Spain

UpConversion (UC) materials are attracting an increasing interest due to their great potential applicability to many fields.

These materials have the great feature to emit at higher energy than that absorbed. This process could take place through different mechanisms, depending on the kind of the involved molecules. Herein we report the UC occurring through triplet-triplet annihilation mechanism in presence of a sensitizer that absorbs the incident light and an emitter that after a triplet-triplet annihilation process emits at higher energy. In this case the sensitizer is a platinum metal complex, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II) (PtOEP), that transfers the absorbed energy to the emitter, 1,3,6,8-tetraphenylpyrene (TPPy) or 9,10-diphenylanthracene (DPA). A preliminary study was performed in homogeneous solutions to evaluate the behaviour of the couple in different solvents. Since practical applications require the upconverting system to be loaded in solid matrices we decided to synthesize upconverting micro- and nanostructured materials. We initially synthesized silica upconverting micro and nanoparticles that present the advantages of being optically transparent, biocompatible, easily achievable, and cost-effective. Synthesis, optical and morphological characterization are reported.

Moreover, given the crucial requirement of the free diffusion of the dyes in the medium for the triplet–triplet annihilation based UC to occur, we focused our attention on polymeric oil-core capsules.

Thus, we obtain a solid system with a solution-like behaviour, wherein the sensitizer and the emitter molecules are actually dissolved into the liquid phase and are able to interact to generate the upconversion.


We present different types of capsules loaded with the upconverting pair and we illustrate their synthesis, morphological and photophysical characterization.

The results herein reported represent a good starting point for future investigations, for example, on different types of sensitizer-emitter couples working in different spectral ranges.

Friday 6th June 9.10 - 9.40 Upconversion Nanoparticles: Materials, Mechanism and Modeling

Andries Meijerinka, Freddy Rabouw

a, Rosa Martin Rodriguez

a

Utrecht University, Princetonplein 5, Utrecht, 3584, NL

Upconversion in nanoparticles is a field of research that is rapidly gaining importance due to new areas of applications, viz. biomedical imaging and spectral conversion for solar cells. In this presentation new efficient upconversion materials will be discussed based on the well known Er

3+-Yb

3+ couple as well

as the potential of other lanthanide ion combinations. Upconversion of IR to NIR radiation has been widely explored for application in c-Si solar cells with a bandgap around 1100 nm. Even larger gains are possible in photovoltaic applications based on wider bandgap materials. For example, for a 750 nm large bandgap solar cell like amorphous Si, upconversion can increase the efficiency by more than 70% for a maximum UC quantum efficiency of 50%. The potential of upconversion nanoparticles is related to the possibility to make transparent upconversion materials due to the absence of light scattering by nanoparticles of sizes well below the wavelength of light. A disadvantage is the lower efficiency of upconversion in nanoparticles. To understand the efficiency and efficiency losses, upconversion mechanism will be discussed, including modeling of energy transfer processes in confined (nano) geometries. Finally the option of sensitized upconversion will be explored giving an outlook on the future applications of UC-nanoparticles for application in solar cells and bio-imaging.

Friday 6th June 9.40 - 10.10 Lanthanide Doped Active-core@active-shell Nanoparticles: Properties, Applications and Challanges

Artur Bednarkiewicz Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, Wroclaw, 50, PL

Lanthanide doped nanoparticles (Ln:NPs) have gained a tremendous interest in the view of their excellent luminescent properties for bio-medical detection and in-vivo / in-vitro imaging. Since most of biological constituents exhibit their spontaneous (auto)fluorescence under photoexcitation typically suitable to excite the fluorescent labels, it is of critical importance to distinguish the useful signals from background. In order to provide sufficient sensitivity of detection, new, long wavelength (i.e. far red or near infrared) absorbing and emitting dyes and semiconductor quantum dots are sought. Lanthanide doped dielectric nanoparticles (Ln:NPs) and especially up-converting nanoparticles (UCNPs) have become interesting alternative to conventional labels due to their perfect photo stability, spectrally narrowband absorption and emission, blinking-free luminescence and most importantly due to efficient anti-Stokes Vis/NIR emission under NIR photoexcitation. Numerous applications have shown the need for luminescent biolabels with intentionally designed properties. In opposite to bulk materials, such optimised materials can be designed with unprecedented precision by using core-(multi)shell approach. The core and shell parts of the nanoparticles can be independent and heterogenously doped with either optically active lanthanides ions or passive ions.

Because it is extremely difficult to compare different materials aiming at studying the impact of synthesis protocols, presence and type of surface ligands, active and passive dopants, morphology, core-shell architecture and structure of nanoparticles onto the suitability of these up-converting nanoparticles for biological applications, we made efforts to quantitatively compare the luminescent properties of different lanthanide doped up-converting nanoparticles. With the presented system, the time resolved spectra as well as absolute quantum efficiency can be measured versus excitation density (from W/cm

2 to MW/cm

2), which is very important for the understanding of energy transfer up-

conversion processes in nano-colloidal particles in confocal microscopy regimes. This lecture will summarise the:(a) properties of lanthanide doped nanomaterials and their bio-

medical applications : main focus will be devoted to the contruction of spectral codes, bio-sensors and bio-imaging luminescent probes(b) state-of-the-art in core-shell designs and properties of such


engineered nanoparticles : main focus will be devoted to active-core@active-shell nanoparticles and Energy Migration Up-conversion(c) the methods to compare properties of luminescent colloidal nanoparticles (time-resolved techniques, power depenedence, quantum efficiency)(d) basic concepts and technical specification of a home-made instrument suitable to study time resolved luminescence and quantum efficiency. (e) properties of active-core@active-shell nanoparticles such as Yb:Ho@Yb:Nd or Yb:Tb@Yb:Nd co-doped NaYF4@NaYF4 core-shell nanoparticles.

Friday 6th June 10.10 - 10.40 Luminescence of Capped Fluorite Nanoparticles Doped with Trivalent Europium

Miju Kima, Hyo Jin Seo

a, Fabio Piccinelli

b, Marco Pedroni

b, Adolfo Speghini

b, Stefano Polizzi

c, Marco

Bettinellib

a, Pukyong National University, 599-1, Daeyeon 3-Dong, Nam-Gu, Busan 608-737, Republic of Korea b, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy c, University of Venezia, Via Torino 155, 30170 Venezia Mestre, Italy

The luminescence of trivalent lanthanide ions (Ln3+

) in the binary fluorides CaF2 and SrF2 has been thoroughly studied in the past, as these materials are considered to be interesting hosts for luminescent ions (especially Er

3+, Tm

3+, Yb

3+) for laser applications. On the other hand, CaF2:Ln

3+, Yb

3+ (Ln=Er, Tm)

fluorite nanoparticles have been investigated as efficient upconverters. In colloidal form they have been recently suggested as optical active ions for imaging in biology and medicine.

The local environment of lanthanide ions present as dopants in CaF2 or SrF2 in nanocrystalline form has not been exhaustively studied in the literature. This can be done by using the Eu

3+ ion as a spectral

probe. The literature about the luminescence of Eu3+

in nanoparticles of CaF2 or SrF2 is not very rich, and, to the best of our knowledge, no study of the optical spectroscopy under high resolution conditions has been carried out for these nanoparticles doped with trivalent europium. For this reason we found it interesting to carry out a detailed study on isolated nanocrystals of CaF2 and SrF2 doped with Eu

3+, with

the ultimate goal of obtaining information on the local structure around the lanthanide ion in fluorite type nanoparticles.The results of this investigation are presented and discussed for fluorite nanoparticles with different capping agents.

Friday 6th June 11.30 - 12.00 Upconversion Processes in Monoclinic Lanthanide Doped KRE(WO4)2 Crystals and Nanocrystals

M.C. Pujola, J. J. Carvajal

a, X. Mateos

a, R. Solé

a, J. Massons

a, M. Aguiló

a, F. Diaz

a

FiCMA- Universitat Rovira i Virgili (URV), carrer Marcel·li domingo, s/n Campus Sescelades, Tarragona, 43007, ES

Monoclinic potassium rare earth tungstates, KRE(WO4)2 ( RE= Gd, Y, Yb and Lu) are a well-known oxide hosts for lanthanide doping ions, for laser applications. The advantages of these materials are the possibility to obtain a high concentrated lanthanide doped samples without distortion or crystallographic stress in the structure; the distribution coefficient around 1 which assures an almost homogeneous distribution of the lanthanide doping ion inside the material, and spectroscopically, the large emission and absorption cross sections. Some of the disadvantages of these materials could be the large anisotropy in their physical properties, and their rather high phonon energy value around 900 cm

-1.

As a bulk single crystal, these materials have been grown by Top Seeded Solution Growth method typically, and they are commercially available. As a nanocrystal, they were prepared for first time in 2007, by Pechini method, obtaining average sizes around 50 nm. In this work, we will review the upconversion processes studied in these hosts; and how these processes have been explored for white light nano phosphor and thermometric nano biosensor applications.

Friday 6th June 12.00 - 12.30 Optical Trapping of NaYF4:Er3+,Yb3+ Upconverting Fluorescent Nanoparticles

Patricia Haro-Gonzáleza, Blanca del Rosal

a, Laura Martínez Maestro

a, Emma Martín Rodríguez

a, Rafik

Naccacheb, John A Capobianco

c, Kishan Dholakia

d, José García Solé

a, Daniel Jaque

a

a, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, Facultad de Ciencias, Departamento de Física de Materiales, Módulo 04, Despacho 613, Madrid, 28049, ES


b, INRS-EMT, University of Québec, 1650 Blvd. Lionel Boulet, Varennes, Québec J3X 1S2, Canada, Canada c, Department of Chemistry and Biochemistry, and Centre for NanoScience Research, Concordia University, 7141 Sherbrooke Street West, SP 201.00, Montreal, Quebec, Canada H4B 1R6, Canada d, SUPA, School of Physics & Astronomy, University of St Andrews , Physical Science Building, North Haugh, University of St Andrews, St. Andrews, KY16 9SS, United Kingdom, United Kingdom

Three-dimensional manipulation and control of single and multiple nanoparticles is key for a variety of applications, including single molecule spectroscopy, colloidal dynamics, tailored particle assembly, protein isolation, high resolution surface studies, controlled investigation of biological processes and surface enhanced spectroscopy. The potential applications of nanoparticle manipulation may be further extended if the nanoparticles in question also act as fluorescent probes, so that their luminescence properties may be used to provide physical and/or chemical cues. Such single particle manipulation may be used for physical/chemical imaging of a variety of systems with reduced sizes (ranging from photonic devices to single cells).

UCNPs have been successfully used for high resolution intracellular dynamical studies, bioimaging and accurate intracellular thermal measurements. However, to the best of our knowledge, optical trapping of single or multiple UCNPs has not yet been demonstrated. Such a step would facilitate exciting new applications. As an example, intracellular fluorescence sensing and imaging is presently achieved by intracellular incorporation of UCNPs, so that UCNPs are distributed over the entire cell volume. The trapping of one single nanoparticle would allow for the mapping of the cell with only one nanoparticle, thus minimizing the perturbations to the system.

We report on the first experimental observation of stable optical trapping of dielectric NaYF4:Er3+,Yb3+ upconverting fluorescent nanoparticles (~26 nm in diameter) using a continuous wave 980 nm single-beam laser. The laser serves both to optically trap and to excite visible luminescence from the nanoparticles. Sequential loading of individual nanoparticles into the trap is observed from the analysis of the emitted luminescence. We demonstrate that the trapping strength and the number of individual nanoparticles trapped is dictated by both the laser power and nanoparticle density. The possible contribution of thermal effects has been investigated by performing trapping experiments in heavy water in addition to distilled water. For the case of heavy water, thermal gradients are negligible and optical forces dominate the trap loading behaviour. The results provide a promising path towards real three dimensional manipulation of single NaYF4:Er3+,Yb3+ nanoparticles for precise fluorescence sensing in biophotonics experiments.

Friday 6th June 12.30 - 12.50 Upconversion Laser Phosphor Displays

Oleksandr A. Savchuka, Joan J. Carvajal

a, M. Cinta Pujol

a, Jaume Massons

a, Magdalena Aguiló

a, Francesc

Díaza

Física i Cristal·lografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili, Marceli Domingo, s/n, Tarragona, 43007, ES

In the last few years, a passionate interest has been growing for controlling the electromagnetic radiation by focusing on patterned structures and materials, especially when the dimensions of the structured material match the wavelength for resonant optical processes. However, light distribution control can also be achieved using patterned structures at a micrometer level. A particularly interesting approach has been the control of light distribution spatially and spectrally generated by optically active trivalent lanthanide (Ln

3+) ions. It has been demonstrated that by embedding Ln

3+-doped nanoparticles

into microstructured materials it might be possible to control the light spatially at the micrometer scale in a wide spectral range.This kind of technology might have interesting implications to reinforce an emerging technology as it is laser phosphor displays (LPD). These devices consist on a scanning laser beam that excites one or more luminescent materials deposition onto a screen which emit light to form images. The present technology consists on parallel stripes of phosphors deposited on a substrate, that emit light of different colors after absorbing the same laser wavelength. By generating a two-dimensional (2D) array of phosphors, intead of parallel strips, a better definition for the pixels on the screen could be envisaged. Also, present technology uses UV excitable phosphors that emit visible light. However, by using upconversion processes, powerful IR laser diodes at low prices can be used for the same purpose.Here we present the fabrication of upconversion laser phosphor displays based on 2D


patterns fabricated on the surface of non-linear optical materials (KTiOPO4) by ultrafast laser ablation and consisting on an array of holes in which upconversion nanoparticles of monoclinic potassium double tungstates have been embedded able to emit blue, green and red light after excitation at 980 nm. The emissive properties of these displays have been analyzed.

Friday 6th June 12.50 - 13.10 Up-converting Oxide Nanoparticles for Solar H2 Generation

Francisco Gonella, Marta Haro

b, Rafael S. Sánchez

b, Patricia Negro

b, Iván Mora-Seró

b, Beatriz Julián-

Lopeza, Sixto Giménez

b, Juan Bisquert

b

a, Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Avd. Sos Baynat S/N CP, Castellon de la Plana, 12071, ES b, Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, Avd. Sos Baynat S/N CP, Castellon de la Plana, 12071, ES

Up-conversion (UC) of infrared photons to visible radiation constitutes a promising strategy to optimize the spectral match between the incident solar radiation and the absorption properties of semiconductor materials employed for light harvesting systems. Several works have been recently reported incorporating fluoride materials in energy conversion devices for application in photovoltaics, photoelectrochemistry

and photocatalysis. Among them, the most efficient hexagonal (β-) phase NaYF4

codoped with Ho3+, Er3+ or Tm3+/Yb3+ ions is known to be the most efficient converter due to its low phonon energy that suppresses nonradiative multiphonon relaxations.

Even so, fluorides present

important drawbacks such as low thermal and chemical stability, high toxicity, high cost and complex synthetic procedures.

In the present study we demonstrate that up-converting Er3+,Yb3+-Y2O3 nanoparticles synthesized with a simple homogeneous co-precipitation method can be harnessed to produce photocurrent with sub-bandgap photons in heterostructured TiO2/CdS photoanodes for H2 generation. These up-converting nanoparticles present an exciting alternative because of their high stability and the ability of tune their structural, morphological and optical features through controlled synthetic pathways. The proof-of-concept device presented here shows promising features for large scale development of low-cost, stable and efficient photoelectrochemical devices for solar fuels production.

Posters sessions Synthesis of Strontium Ytrium Flourides Using Co-Pprecipitation Method Danas Sakalauskas

a, Simas Sakirzanovas

a, Aldona Beganskiene

a

Faculty of Chemistry, Vilnius University, Naugarduko 24, Vilnius, LT

Nowadays the demand to find new techniques for the facile synthesis of nanosized phosphors is increasing. Ultrasmall, monodispersed light-emitting nanomaterials have real and potential applications in solid-state lasers, bioimaging, optical data storage and 3D flat-panel displays. Recently it was reported that colloidal α- or β-phase NaYF4 hosts doped with RE (RE = Er, Yb, Ho or Tm) are the best candidates for biological applications. However, there are only a few reports on a series of alkali-earth–rare-earth complex fluoride, xMF2–yRREF3 (M = Na, Ba, Sr), (R = Y, Gd), (RE = Er, Yb, Ho or Tm) ternary compounds. It is expected that the alkali-earth–rare-earth complex fluorides have tetragonal and hexagonal phase structure and might possess highly efficient upconversion (UC) emission. SrY2F7 have been selected, as the research object, because of its potential applicability as suitable host for biological applications, where one of the major requirements is nanoparticle size. As mentioned alkali-earth–rare-earth complex fluoride are promising host material for UCNPs, mainly because of low phonon energy. SrY2F7 particle size are dependent on the nucleation rate, which in turn, is governed from the reagents concentration, molar ratio, choice of capping ligand, reaction temperature and pH. SrY2F7 samples were synthesized using co-precipitation method. All samples were analyzed using X-Ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS) and infrared spectroscopy (FTIR). By tuning the ratio of Sr/Y/F, solvent composition, reaction temperature and time, it is possible to synthesize nanoparticles of different size and shape. Fluorine amount in starting mixture, synthesis temperature, pH and surfactant concentration influence for particle size and shape will be discussed.


Posters sessions Upconverting NaYF4 and NaGdF4 Nanoparticles Doped with Rare-Earth Ions for Bioimaging Applications

Aldona Beganskienea, Ieva Mikalauskaite

a, Aivaras Kareiva

a, Vitalijus Karabanovas

b, Ricardas Rotomskis

b,

Ieva Lebedytea

a, Department of Inorganic Chemistry, Vilnius University, Naugarduko 24, Vilnius, LT b, Institute of Oncology, Vilnius University, Baublio 3B, Vilnius, LT

Traditional biological labels such as organic dies, quantum dots and fluorescent proteinsrevealed several undesirable side effects, more effort were concentrated to an increasing class of fluorophores - upconverting nanoparticles (UCNP‘s). Being biocompatible, nontoxic, having longer detection times, good chemical and physical stability and lower autofluorescence rare-earth doped UCNP‘s are promising alternatives for potential biological and medical applications. These nanoparticles offer high photostability and enable deep tissue-penetration depths (up to 10 mm) by irradiation with near-infrared (NIR) light, which makes them particularly attractive for bioimaging applications. Biomedical application of UCNP‘s have also been studied in the past few years, mainly focused on the photodynamic therapy (PDT) relying on the resonance energy transfer from UCNPs to PDT photosensitive molecules under the NIR light irradiation.

In order to obtain multifunctional both fluorescent and magnetic resonance imaging (MRI) contrast agents, Gd

3+ ions are used as activators in host lattice of NaREF4. Also, for comparison of luminescence

properties the doped NaYF4nanoparticles were synthesized. One of the most common route of synthesis for NaYF4 :Yb

3+, Er

3+, Tm

3+ (or NaGdF4 with same dopant ions) the thermal decomposition in organic

solvent was used for preparation of nanoparticles. By changing conditions of a synthesis, different phase (cubic or hexagonal) and size NaREF4:Yb

3+, Er

3+, Tm

3+ nanoparticles were obtained and analyzed with

fluorescence spectrometer (PL), scanning electron and transmission microscopy, (SEM and TEM), X-ray diffraction (XRD) and infrared spectroscopy (FTIR) instruments.

To achieve hydrophilic particles, surface coating ligand (oleic acid) was modified with nonionic triblock copolymer (poly(ethylene oxide)-block-poly(propilene oxide)-block-poly(ethylene oxide)). Highly efficient luminescent UCNP’s which could be used for biological applications as bioimaging dies (NaYF4 NaGdF4 ) for cell visualization and as MRI agent (NaGdF4) were prepared. Also, the data of distribution and toxicity of nanoparticles in cells or in tumor of mice will be presented.

Posters sessions Curcubit[7]urils-capped NaYF4: Yb3+(18%), Er3+(2%) Nanoparticles

Laura Francés-Sorianoa, María González-Béjar

a, Julia Pérez-Prieto

a

Universitat de València, C/ Catedrático José Beltrán 2, Paterna (Valencia), 46980, ES

Surface modification of nanoparticle with cyclic molecules wich have molecular recognition abilities holds great importance in the construction of functional nanodevices. Curcubit[n]urils (CB[n]) are a family of water soluble macrocycles of glycoluril units which have increased their interest due to their unique structure and superior molecular recognition abilities.

Their structure is like a pumpkin with a

hydrophobic cavity which is accessible through carbonyl groups located at the edges. Their internal cavity is capable of forming strong inclusion complexes with molecules and ions and this make them suitable for constructing sensors, drug delivery and biomimetic systems. Some studies demonstrate the interaction between CB[n] and metallic nanoparticles (silver or gold) and lanthanide cations.

Up-conversion nanoparticles (UCNPs) are interesting due their emission properties. When exciting them with NIR light, UCNPs emit in the visible. Generally, UCNPs are synthetized with organics ligands and present non water-dispersibility which limit their application in biological systems.

We have synthesized oleate-capped NaYF4: Yb

3+(18%), Er

3+(2%) UCNPs following an already

described protocol. Subsequently we have made them water-dispersible by efficient exchange of the

oleate capping for CB. These nanohybrids have been fully characterized and the resulting data will be discussed.


Acknowledgements: We thank the Spanish Ministry of Economy and Competitiveness (Project CTQ2011-27758, M.G.B Juan de la Cierva contract and L.F.S. FPU). This research was supported by a Marie Curie Career Integration Grants within the 7th European Community Framework Programme. Posters sessions Hydrothermal Synthesis and Up-conversion Properties of BaREF5:Yb3+/Ln3+ (RE = Y, Gd, Lu; Ln = Er, Ho, Tm) Nanomaterials

Tomasz Grzyb, Sangeetha Balabhadra, Dominika Przybylska, Mariusz Weclawiak Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, Poznan, 61-614, PL

Nanomaterials based on BaREF5 fluorides (where RE = Y, Gd and Lu), doped with lanthanide ions Yb

3+/Ln

3+ (Ln = Er, Ho or Tm) where synthesized by microwave assisted hydrothermal method. The way

of synthesis, structural and morphologic properties will be reported and discussed. The morphology of BaREF5 nanomaterials varied from spharical nanocrystals with average size around 45 nm to ring-like structures with a diameter around 210 nm. Obtained products showed visible up-conversion luminescence excited by the laser light with wavelength around 978 nm as the consequence of energy transfer between Yb

3+ and Ln

3+ ions. Their spectroscopic properties were characterized on the basics of

excitation and emission spectra. Also recorded luminescence decays and emission power dependencies will be presented. Compared materials showed differences in their structural properties what reflected also spectroscopic characteristics. The most intense luminescence was registered for BaLuF5 based materials. In this host compound, the emissions from Er

3+ and Tm

3+ ions were especially efficient

showing also transitions from higher excited states, requiring more than two photons to be populated.

Posters sessions Upconverting Luminescent Carbon Nanodots

Mari Carmen Ortega-Liébanaa, José L Hueso

b, Raúl Arenal

c, Jesús Santamaría

d

a, Institute of Nanoscience of Aragon (INA) and Department of Chemical Engineering and Environmental Technology, University of Zaragoza., C/ Mariano Esquillor, s/n. Ed I+D. Campus Río Ebro, 50018, Zaragoza., ES b, CIBER-Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN, 50018, Zaragoza., ES c, Advanced Microscopy Laboratory (LMA) and Institute of Nanoscience of Aragon (INA), C/ Mariano Esquillor, s/n. Ed I+D. Campus Río Ebro, 50018, Zaragoza, ES d, ARAID Foundation, Zaragoza, ES

Luminescent carbon nanodots (CNDs) are newcomers to the world of nanomaterials and have shown great impact in health and environmental applications because of their fascinating photoluminescence and potential to serve as nontoxic replacements for traditional heavy-metals-based quantum dots. Such nano-materials have been distinguished from traditional fluorescent materials as promising benign candidates for various potential applications including biomedical imaging, photocatalysts, sensors and optoelectronic devices.

Herein, we present a simple, low-cost and green approach to obtain highly fluorescent CNDs by pyrolysis treatment. Several characterization techniques such as HR-TEM, EELLS, FT-IR, XPS and UV-Vis spectroscopy have shown the production of carbon nanodots with emission ranges from UV to green with high quantum yields and long-term stability. By combining free dispersion in water, size-dependent optical properties, and upconverting properties, CNDs may provide a new type of fluorescent markers as well as a new approach to high-efficiency material design for applications in bioscience and energy technology.

Posters sessions Cyclodextrin-Coated Gold Nanoparticles as Platforms for Plasmon-Induced Photoreactions

Marc Padillaa, José Luis Bourdelande

a, Jordi Hernando

a

Universitat Autònoma de Barcelona (UAB), Campus UAB Bellaterra, Cerdanyola del Vallès, 08193, ES


Noble metal nanostructures such as gold nanoparticles (Au NPs) display a unique optical behavior arising from the resonant excitation of their collective free electron oscillations, the so-called surface plasmon resonance. Electromagnetic field enhancement, generation of energetic charge carriers and local conversion of photon energy into heat are some of the most relevant properties resulting from plasmon excitation, which are currently being exploited in a large variety of applications. Among them, Au NPs have been proposed for the sensitization of organic photoreactions with visible light, which are normally initiated by plasmon-induced photothermal effects and/or charge transfer. Since these processes are highly distance dependent, care has to be taken to ensure maximal approach of the substrate molecules to the nanoparticle surface. For instance, this can be achieved by means of naked, non-coated Au NPs. In this communication we present an alternative strategy towards this aim, which relies on the use of cyclodextrin-coated gold nanoparticles (CD@Au NPs). Exploiting the capacity of cyclodextrins to form inclusion complexes with a wide range of organic compounds as well as their well-known activity as photochemical templates, CD@Au NPs are devised to (i) accelerate plasmon-induced photoreactions by inducing the substrate molecules to move in close proximity to the metal surface, and (ii) favor reaction selectivity. As a proof of principle of this approach, in this work we have synthesized thiolated cyclodextrin derivatives, coated gold nanoparticles with them and tested the photocatalytic activity of the resulting assemblies in some benchmark photochemical reactions.

Posters sessions Energy Migration Upconversion in Active-core/Active-shell NaYbF4:Tb3+@NaYbF4:Nd3+ Colloidal Nanoparticles

Katarzyna Proroka, Artur Bednarkiewicz

a, b

a, Wrocław Research Centre EIT+, ul. Stabłowicka 147, 54-066 Wrocław, PL b, Institute of Low Temperature and Structure Research Polish Academy of Sciences, ul. Okólna 2, 50-422 Wrocław, PL

Energy Transfer Upconversion (ETU) with rare earth (RE) doped nanocrystals has drawn a lot of attention in recent years. Although Yb

3+ sensitized ETU is relatively efficient, many applications, such as

biodetection and bioimaging, still suffer from low absorption cross section (σABS) of RE ions and low quantum yield of ETU phenomenon. Due to around 5-fold larger σABS of Nd

3+ ions and low σABS of water

at ~800 nm (4I9/2→

4F5/2 :Nd

3+) in respect to ~980 nm (

2F7/2→

2F5/2 : Yb

3+) of conventional Yb

3+ sensitizer,

Nd3+

ions are considered to be a good alternative for improving pumping efficiency. Interestingly, the energy transfer between the Nd

3+ 4F3/2 and Yb

3+ 2F5/2 states reached nearly 90% efficiency. It was

demonstrated that the Yb3+

ions can act as efficient energy migrators, facilitating energy transfer from Nd

3+ ions to actual activator ions. Additionally, the use of Nd

3+ ions as sensitizers significantly minimizes

the overheating, which is caused by conventional 980 nm excitation through water absorption. On the other hand, the introduction of Nd

3+ ions as sensitizers may directly quench the up-conversion emission,

due to the energy transfer between Nd3+

and activators. For this reason, separating the Nd3+

and activator spatially is necessary. A promising method to avoid parasitic ET processes could be designing a core-shell structure where the activator and Nd

3+ ions will be separated in the core and shell,

respectively. In our work the impact of the concentration of the neodymium ions on the efficiency of upconversion energy (800 nm and 975 nm excitation) was investigated. A relatively high concentration of primer sensitizing Nd

3+ ions doped in the shell host allows for effective absorption of the excitation

NIR energy (around 800 nm) and subsequent energy transfer to secondary sensitizer Yb3+

ions and followed by excitation and emission from activator Tb

3+ ions.

Acknowledgement: The research was supported by Wrocław Research Centre EIT+ and under the project “The Application of Nanotechnology in Advanced Materials” NanoMat (POIG.01.01.02-02-002/08) financed by the European Regional Development Fund (Innovative Economy Operational Programme, 1.1.2)

Posters sessions Near Infrared Activation of Pt(IV) Anticancer Agents by Upconverting Nanoparticles

Emmanuel Ruggieroa, Juan C. Mareque-Rivas

a, b, Luca Salassa

a

a, CIC biomaGUNE, Paseo Miramon 182, Donostia, 20009, ES b, IKERBASQUE, Basque Foundation for Science, Bilbao, 48011, ES


Photodynamic therapy (PDT) is emerging in the clinics as an alternative therapeutic protocol to traditional cancer treatments. PDT kills cancer cells by generating reactive species upon light excitation of a prodrug (i.e. photosensitizer). Light activation allows to control spatially and temporally the effects of the treatment, decreasing systemic toxicity of anticancer agents and limiting unwanted side effects.

On the bases of the success of Pt(II) and Pt(IV) anticancer agents, several photoactivatable Pt(IV) anticancer agents have been developed for PDT in the last few years. However, such photoactive systems all suffer from the need of high-energy UV or visible light for activation, which is not ideal for in vivo applications since low tissue penetration is achieved at such wavelengths and cellular damage can be induced.

Coupling photoactivatable anticancer complexes with upconverting nanoparticles (UCNPs) is a promising strategy to overcome such challenging limitation. UCNPs can convert NIR light into UV-visible light, meeting metal complexes' demand for high-energy light excitation. Recently, we have demonstrated the photoactivation of Ru polypyridyls by UCNPs and we are currently extending the strategy to light-sensitive Pt(IV) anticancer complexes.

In this contribution we will discuss our advances in the design of hybrid systems which combine biocompatible UCNPs with Pt(IV) prodrugs. Our efforts are ultimately aimed at developping theranostic nanoplatforms that are capable of releasing cytotoxic platinum species under NIR activation and that allow visualization via multimodal imaging methods.

Posters sessions Up-converting Materials for Further Improvement of the Light Harvesting Efficiency of Lead Perovskite Solar-Cells

Rafael S. Sáncheza, Francisco Gonell

b, Sixto Giménez

a, Juan Bisquert

a, Beatriz Julián-Lopez

b, Iván Mora-

Seróa

a, Universitat Jaume I, Photovoltaic and Optoelectronic Devices Group, Edificio investigación nº1, Spain b, Universitat Jaume I, Multifunctional Materials Group, Department de Química Inorgànica i Orgànica, Spain

Lead halide perovskite derivatives (CH3NH3PbX3, X= Cl, Br, I) have become very promising materials for photovoltaics during the last two years due to their relatively easy processability, high light absorption coefficients, excellent electrical properties and most importantly, the recent steep rate of improvement in perovskite solar-cell performance, which reaches values of power conversion efficiency as high as 15-16% up to date. The rapid advance of the perovskite solar-cell technology could presage that in the next years, the power conversion efficiency will approach its theoretical maximum value. Thus, additional strategies aimed to overcome this limitation are needed to be exploited: i) broadening of the light harvesting absorption range of the perovskite films; or ii) preparation of tandem configuration devices; among others.In this work, we focus on the first approximation and propose the combination of lead perovskite materials together with up-converting materials as an appealing mechanism to further extend the absorption of sub-bandgap photons through multi-photon transitions. In this context, the use of lanthanide up-converting (UC) nanocrystals, which are able to transform infrared photons into visible radiation, opens new exciting opportunities to develop more efficient devices. The most studied UC systems to date involve lanthanide (Yb

3+, Er

3+, Tm

3+) doped fluoride or

oxide materials. Herein, we report for the first time, up to our knowledge, the integration of Er

3+/Yb

3+ codoped yttrium oxide (Y2O3) nanoparticles with outstanding UC properties, into perovskite

based devices with the aim of extending the spectral range of photon to current functionality.


Posters sessions Up-conversion phenomenon in BaREF5:Yb3+,Er3+ nanosystems (RE = Gd and Lu) co-doped with Mn2+or Nd3+ ions Agata Szczeszak*, Tomasz Grzyb Adam Mickiewicz University, Faculty of Chemistry, Department of Rare Earths, Umultowska 89b, Poznan, 61, PL

These days, scientists are still looking for proper materials that can be easily used in diagnosis and cancer treatment. Luminescent materials, especially inorganic nanophosphors containing lanthanide ions, Ln3+, are still one of the most significant compounds that can be applied in fluorescence imaging, biolabelling or drug delivery. This kind of systems are promising due to visible and intensive anti-Stokes emission, called up-conversion (UC). This phenomenon involves conversion of the near infrared (NIR) or infrared (IR) low-energy radiation to high-energy ultraviolet (UV) or visible (Vis) light. Literature describes various mechanisms associated with multiple absorptions or energy transfers responsible for the conversion, which can occur singly or several at the same time. In order to obtain efficient up-conversion emission matrices based on BaGdF5 and BaLuF5 compounds, doped with Ln3+ ions (Yb3+ as a sensitizer and Er3+ as emitter) and Mn2+ions or Nd3+, were selected. Fluorides are very promising UC materials due to their low phonon energies, which enable to reduce non-radiative relaxations. Also there are many effective ways of their synthesis at nanoscale. Introduction of the additional Mn2+ ions intended to tune green and red up-conversion emission. The influence of Mn2+ ions on the emission intensity was also studied. Additionally, BaREF5:Yb3+,Er3+ nanophosphors were also doped by Nd3+ions, which played a role of absorbers of the NIR radiation and shifted the excitation wavelength to 800 nm. Posters sessions Microwave-assisted Synthesis and Single Particle Spectroscopy of Infrared Down- and Visible Up-conversion in Er3+ and Yb3+ co-doped Fluoride Nanowires

Dominika Wawrzyoczyka, Marcin Nyk

a, Dawid Piatkowski

b, Sebastian Mackowski

b, Marek Samod

a

a, Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, Wroclaw, 50, Poland b, Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland

Lanthanide-doped nanoparticles (NPs) with precisely designed size and shape, as well as thoroughly characterized spectroscopic properties are attractive candidates for new types of optically active labels for microscopic techniques. Thus, establishing reliable, cheap and reproducible methods to synthesize lanthanide-doped NPs of different sizes and shapes is crucial, as the morphology can strongly influence the spectroscopic properties of those nanoluminophores. Additionally, for labeling applications it is very important to precisely characterize the spectroscopic properties at a single NP level, the luminescence intensity of a single NP being one of the relevant parameters in optical imaging.

Lanthanide-doped up-converting NPs are promising candidates for microscopy labeling applications, because of the possibility to excite their characteristic emission with light from the near-infrared region, which is less susceptible to scattering and can penetrate deeper through the investigated species. Such NPs also show only little photobleaching and photoblinking, and thus are promising candidates for single-particle tracking.

Here we report the synthesis of high-quality rare-earth doped NaYF4 nanowires, with the use of oleic acid as a capping agent through the microwave assisted hydrothermal technique. The utilized synthesis protocol resulted in formation of 1μm×100nm long nanowires with a high length:diameter aspect ratio. The phase, shape and size of the particles were examined with TEM and SEM imaging. Er

3+ and Yb

3+ co-

doped nanowires excited with a 976 nm laser diode exhibited strong anti-Stokes emission peaking at 540 nm/654 nm, and Stokes emission within the conventional telecommunication C-band transmission window at 1524 nm. We have investigated the power dependence of both up- and down-conversion emission. Additionally, we have performed diffraction-limited, single-particle imaging and steady-state and time response spectroscopy of the synthesized nanowires, in order to show their suitability for various optical imaging experiments.


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Fluorescent Up-converting Nanoparticles: a Platform for ...nanoge.org/.../docs/BookAbstractsFUN-Bioenergy14.pdf · Lanthanide doped nanoparticles have the ability to undergo upconversion