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REVIEW 1
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Electrochemical enzymatic biosensors based on metal micro-/nanoparticles-3
modified electrodes: a review 4
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Nina D. Dimcheva*, Elena G. Horozova 6
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Department of Physical Chemistry, Plovdiv University, 24, Tsar Assen Street, BG-4000 8
Plovdiv, Bulgaria 9
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Received 17 March 2014; Revised 6 June 2014; Accepted 6 June 2014 11
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The functions of metal structures of micro- or nano-dimensions in the sensing 14
mechanisms of amperometric enzyme-based biosensors are considered in the light of the 15
principles of detection of the latter. The applications of metal mono- or bimetallic 16
nanoparticles-modified materials as catalytic electrodes in the fabrication of first-generation 17
and the role which metal nanoparticles play in promoting or enhancing the electron transfer 18
rates in third-generation electrochemical biosensors are reviewed. Some examples of gold 19
NPs functionalised with enzymes via gold–thiol chemistry as a strategy for enzyme 20
immobilisation and spatial orientation when developing amperometric biosensors are also 21
discussed. 22
2014 Institute of Chemistry, Slovak Academy of Sciences 23
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Keywords: nanoparticles, biosensors, electrocatalysis, direct electron transfer (DET) 25
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Introduction 28
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The first historical proof of the fabrication of metal nanoparticles dates back to the 30
times of the Roman Empire, as evidenced by an artefact currently in the British museum – the 31
dichroic Lycurgus Cup. Due to the incorporation of gold (Au) and silver (Ag) nanoparticles in 32
*Corresponding author, e-mail: [email protected]
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the glass, its colour appears greenish in a reflected light or ruby-red when light is transmitted 33
through the glass (Freestone et al., 2007). In the Middle Ages, Au nanoparticles of different 34
sizes were used to produce intensively-coloured glass for the stained-glass windows of the 35
cathedral churches of Europe, e.g. Notre Dame de Paris (Aili & Liedberg, 2010). Nowadays, 36
the ever-increasing interest in fabricating metal nanoparticles results from the diversity of 37
their possible applications,, ranging from tumour diagnosis (Wilson, 2008) through 38
electrocatalysts for energy production (Alexeyeva et al., 2006; Bron, 2008; El-Deab, 2010; 39
El-Deab & Ohsaka, 2002a, 2003, 2006, 2007; El-Deab et al., 2005a; Erikson et al., 2009; 40
Lima et al., 2010; Plyasova et al., 2006; Ramos et al., 2010; Sekol et al., 2013) to plasmonic 41
resonance-based sensing (Chandrasekharan & Kamat, 2001; Freeman et al., 1996; Gartia et 42
al., 2013; Ghosh & Pal, 2007; Ishikawa et al., 1996; Jäckel & Feldmann, 2012), e.g. surface 43
plasmon resonance (SPR) or surface-enhanced Raman scattering (SERS). This broad 44
spectrum of applications for nanosized metal particles predetermines the diversity of the 45
protocols for their fabrication, such as wet chemical techniques (Bharathi & Lev, 1997; Sau & 46
Rogach, 2012; Turkevich & Kim, 1970; Turkevich et al., 1951, 1953), photo-decomposition 47
(Krasnansky et al., 1991) and thermal decomposition of salts (Mao et al., 2013; Xue et al., 48
2001), vapour deposition (Whyman, 1996), sputtering (Ishikawa et al., 1996; Mizsei et al., 49
1998; Terauchi et al., 1995), acoustic (Mizukoshi et al., 1997) or radio-frequency-based 50
(Terauchi et al., 1995) methods and miscellaneous electrochemical-deposition techniques 51
(Chikae et al., 2006; Dai & Compton, 2006; Dobbs et al., 2006; El-Deab, 2010; El-Deab & 52
Ohsaka, 2002a; El-Deab et al., 2005b, 2006; Fu et al., 2010; Gao et al., 2005; Gloaguen et al., 53
1999; Ilias et al., 2013; Ma et al., 2009; Plyasova et al., 2006; Quinn et al., 2005; Sau & 54
Rogach, 2012; Tang et al., 2012; Wang et al., 2008, 2009), etc. Due to the numerous 55
advantages which they offer, e.g. the opportunity to tune the particle size and distribution 56
(Plyasova et al., 2006), improved mechanical stability (El-Deab, 2010) and better electrical 57
contact (El-Deab & Ohsaka, 2007; El-Nagar et al., 2013) with the underlying substrate, 58
electrochemical techniques for the deposition of metal nanoparticles on conductive supports 59
are favoured for producing electrocatalysts applicable in either electroanalysis (Zhang et al., 60
2013) or energy-producing devices (Alexeyeva et al., 2006; Bron, 2008; El-Deab, 2009; El-61
Deab & Ohsaka, 2002b, 2003, 2006, 2007; El-Deab et al., 2005a, 2005b, 2005c, 2006; 62
Erikson et al., 2009; Sekol et al., 2013; Shao et al., 2013). 63
Biosensor technologies represent one of the research areas in which nano-materials 64
play important roles in the sensing process. As defined by IUPAC (IUPAC, 2005–2014), a 65
biosensor is a device that makes use of specific biochemical reactions catalysed by a 66
3
biological element for molecular recognition, such as isolated enzymes, antigens/antibodies, 67
nucleic acids, tissues, organelles or whole cells in order to detect chemical compounds, 68
usually by electrical, thermal or optical signals. 69
Electrochemical biosensors possess two main advantages over the other types of 70
biosensors: (i) susceptibility to miniaturisation, and (ii) facility of operation with electrical 71
response – current, potential, or conductivity, which could be easily processed using relatively 72
inexpensive instrumentation. 73
Depending on the type of the measurable response, they could be sub-divided into 74
three types: (i) amperometric – the measurable response is the current, which varies upon 75
addition of the enzyme substrate; (ii) potentiometric – the potential difference between the 76
working and the reference electrode measured under equilibrium conditions (no current 77
flowing) is the electrode response; (iii) impedimetric – the impedance of the electrode is the 78
measurable response. Biosensors measuring the conductivity changes upon the addition of the 79
enzyme substrate can be also considered in this group. 80
Among the electrochemical biosensors, enzyme-based amperometric biosensors 81
represent the most commonly used group; this functions on the basis of monitoring the current 82
variation at a polarised electrode, induced by the reaction/interaction of the bio-recognition 83
element with the analyte of interest. Furthermore, amperometric enzyme-based biosensors 84
can, on their part, be classified into three categories in accordance with the mode of action 85
(Montornes et al., 2008): (i) first-generation biosensors: the signal corresponds to the 86
electrochemical reaction of an active reagent (monitoring the decrease in the current) or 87
product (monitoring the increase in the current) that is involved in biochemical transformation 88
of the target compound; (ii) second-generation biosensors: the architecture of these biosensors 89
includes a redox mediator either freely diffusing or spatially confined on the electrode surface 90
(small molecular mass compounds, able to effectively shuttle electrons between the electrode 91
surface and the enzyme active site); in this mode, the concentration of the target analyte 92
taking part in the biochemical reaction is proportional to the response resulting from the 93
oxidation/reduction of the mediator; (iii) third-generation biosensors: the bio-component is 94
capable of directly (mediators-free) exchanging electrons between the active site of the 95
enzyme and the transducer (Ghindilis et al., 1997; Gorton et al., 1999); consequently, the 96
concentration of analyte is directly proportional to the redox current generated at the polarised 97
electrode. The third-generation biosensors possess the advantages of simplicity of 98
construction, exclusion of additional supportive substances (e.g. mediator), increase in 99
4
specificity for towards target analyte, removal of interferences due to the usually low 100
polarisation potential at the working electrode, etc. 101
In the past decade, several review papers comprehensively discussed the uses of the 102
magnetic, optical, chemical and physical properties of nanoparticles of different natures in 103
bioanalytical techniques (de Dios & Díaz-García, 2010; Doria et al., 2012; Luo et al., 2006) 104
such as immune-assay, plasmonic biosensors, nucleic acids-based sensors, etc. The current 105
review focuses in particular on the roles played by metal nano- and microparticles-modified 106
electrodes in the first- and third-generation amperometric biosensors – they may have 107
electrocatalytic properties towards the redox transformation of a reaction product or reagent, 108
may bind to the biocatalyst, thereby retaining it closer to the electrode surface, they may also 109
affect enzyme-orientation or reduce the distance between its active site and the electrode 110
surface. Second-generation biosensors will be excluded from this review since they require a 111
redox-active species able to switch between the oxidised and the reduced form in order to 112
mediate the electron transport between the electrode and the enzyme active site. 113
114
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First-generation biosensors 116
117
The simplest way to construct an enzyme electrode working for the first-generation 118
(1G) amperometric biosensors is to put a biocatalyst in contact with a catalytic electrode. As 119
stated above, the detection of the analyte is based on the monitoring of the current variation 120
due to the redox transformation of either an electroactive product or a reagent of the 121
biocatalysed process. Accordingly, a hydrogen peroxide-producing or -consuming enzyme or 122
protein is often used as a biocatalyst, although two non-oxidative enzymes, urease and 123
acetylcholinesterase (AChE), are also known to work for the first-generation amperometric 124
biosensors. In this case, the metal nano- or microparticles (NPs or MPs)-modified transducer 125
may function as either the electrocatalysts of the response-generating process or they act as 126
anchors to which the enzyme is attached. 127
128
129
Biosensors based on detection of enzymatically produced hydrogen peroxide 130
131
Hydrogen peroxide (H2O2) is usually generated as a by-product in most of the 132
enzyme-catalysed oxidative reactions, where its quantity is directly proportional to the 133
5
concentration of the analyte of interest – the enzyme substrate. H2O2 is the electrochemically 134
active compound and might be electrocatalytically oxidised on solid platinum (Pt) electrodes 135
at an applied potential of 0.6 V (vs Ag/AgCl) (Charmantray et al., 2013). Several examples, 136
however, have shown that the electro-oxidation of enzymatically generated H2O2 onto the 137
electrodes modified with Pt NPs (Olivia et al., 2004), Pt NPs–CNT composite (Zhao et al., 138
2007), Ir NPs (Hsu et al., 2010) or with bimetallic Pd/Pt microdeposits (Horozova et al., 139
2000) affords a more sensitive determination than the bulk Pt electrode. 140
The main drawback of this type of sensing is that, at the operating potentials at which 141
the electrooxidation of H2O2 takes place (i.e. above 0.5 V), organic compounds such as 142
ascorbic or uric acids, some neurotransmitters, antioxidants, pigments, drugs, etc., normally 143
present in the real samples, could be co-oxidised, thereby contributing to the electrode 144
response, which consequently results in overestimated analyte levels. One strategy to 145
overcome this issue is to cover the electrode surface with a perm-selective membrane to 146
restrict the access of the potentially interfering compounds (Kirwan et al., 2007). A much 147
more successful strategy, however, is to electrochemically reduce the peroxide at operating 148
potentials close to 0 V over electrodes modified with metal – mostly iron, hexacyanoferrates 149
(Karyakin, 2001), such as Prussian Blue (also known as artificial peroxidase). Although the 150
preparation of these modifiers is easy, their applications are rather limited because they form a 151
stable film only under acidic conditions, whilst at neutral and slightly alkaline pH they 152
dissolve and tend to lose their catalytic activity. 153
An alternative to the hexacyanoferrate-modified transducers for first-generation 154
biosensors which provides a stable electrode response over a pH range of 3 to 11, was 155
proposed previously (Dimcheva et al., 2002a, 2002b). These first-generation biosensors were 156
based on conventional graphite electrodes onto which a thin layer of bimetallic catalytic 157
phase, consisting of palladium (Pd) and Pt, was allowed to grow through electrodeposition at 158
a constant potential. Subsequent studies showed that the electrocatalytic activity towards 159
H2O2 reduction depended on the ratio at which the two metals were deposited (Dodevska et 160
al., 2006; Nagaiah et al., 2013). Hence, the biosensors thus produced exhibited a practically 161
interference-free response towards the target analyte (Dodevska et al., 2010; Horozova et al., 162
2009) due to the near-zero operating potential. Detailed SEM studies of the electrodeposited 163
bimetallic phases (Nagaiah et al., 2013) demonstrated that the deposits consisted of nanosized 164
crystallites which formed bigger agglomerates upon piling up, the shape and dimensions of 165
which were closely dependent on the ratio of the two metals. In the same study, XRD 166
confirmed that the two co-deposited metals formed alloys, thus explaining why their catalytic 167
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activity towards H2O2 electroreduction greatly exceeded those of the solely Pd or Pt deposits. 168
Several examples of first-generation biosensors where the detection principle resides in the 169
electroreduction of the enzymatically generated H2O2 are summarised in Table 1. As seen 170
from the examples presented, in all the cases the detection of H2O2 is performed over the 171
potential range of −0.1–0.2 V, in neutral buffers. Under such operating conditions, it is 172
scarcely conceivable that some of the substances normally present in real samples, such as 173
glutathione or other antioxidants, neurotransmitters, phenols, etc. might be electrochemically 174
active and contribute to the electrode response. Therefore, as discussed above, the reduced 175
working potentials warrant a practically interference-free assay of the target analyte. 176
177
178
Two further examples of first-generation biosensors 179
180
Urease is a hydrolase-type enzyme which catalyses the hydrolysis of urea to 181
ammonium and bicarbonate ions according to the equation (Singh et al., 2008): 182
183
NH2CONH2 + 3H2O 2NH4 + OH– + HCO3
urease –+ (1) 184
185
Because the pH of the medium changes upon release of these ions, urease-based 186
potentiometric biosensors are quite commonly used for urea monitoring. This type of 187
biosensors was extensively discussed in two recent reviews (Dhawan et al., 2009; Singh et al., 188
2008), and will not be considered here as being beyond the scope of this review. 189
Electrodeposited rhodium nanoparticles were recently reported as exhibiting a 190
significant catalytic effect on the electro-oxidation of enzymatically liberated ammonia 191
(Velichkova et al., 2011) by the urease-based amperometric biosensor. A similar effect was 192
reported by Jia et al. (2011) due to the Pt-nanoflowers-decorated transducer of their biosensor 193
for urea. Some other nanoparticles-modified electrode materials have been found to contribute 194
to increased sensitivity of the determination, e.g. Ag NPs (Crespilho et al., 2009), Au NPs 195
(Do et al., 2011), or Au NPs-polymer composite material (Tiwari et al., 2009); however the 196
role of the metal nanoparticles is not justified. 197
Acetylcholinesterase (AChE) also belongs to the hydrolases group; it plays a key role 198
in the nervous system of mammalian organisms as one of the factors responsible for 199
transmitting nerve impulses to the cholinergic synapses (Arduini et al., 2010). It may readily 200
7
be inhibited by a variety of toxic compounds: heavy metals, nicotine and neuroparalytic gases, 201
medications for the treatment of Alzheimer’s or Parkinson’s diseases, or pesticides 202
(organophosphorous and carbamate types). The enzyme catalyses the hydrolysis of 203
acetylcholine to choline and acetic acid. Since none of these reaction products is 204
electrochemically active, acetylthiocholine is often used as an enzyme substrate (Pandey et 205
al., 2000). The principle of the detection of AChE enzyme inhibitors using acetylthiocholine 206
as the enzyme substrate lay in the following three stages (Arduini et al., 2010; Stoytcheva et 207
al., 1998). Stage 1: AChE catalyses the hydrolysis of acetylthiocholine to thiocholine and 208
acetic acid at ambient temperature: 209
210
Acetylthiocholine + H2O Thiocholine + CH3COOHAChE
(2) 211
212
Both the non-enzymatic and the enzymatic hydrolysis of acetylthiocholine to thiocholine 213
depended on the pH of the solution and were found to slow down in basic media; stage 2: 214
electrochemical oxidation of thiocholine onto the electrode surface: 215
216
2Thiocholine Disulphide + 2H+ + 2e–anodic oxidation
(3) 217
218
The process takes place with the transfer of one electron from the thiocholine and the 219
subsequent dimerisation of the intermediate to disulphide. When conventional electrodes are 220
used (Martorell et al., 1994; Marty et al., 1992, 1995), thiocholine electro-oxidation proceeds 221
at potentials greater than 0.7 V (vs SCE); stage 3: upon the inhibition of the AChE enzyme, 222
the thiocholine oxidation current decreases. The extent of enzyme inhibition is determined in 223
accordance with the equation: 224
225
%100InhibitionS
IS
I
II (4) 226
227
where IS is the steady-state electrode response to the control solution (at the large thiocholine 228
concentration present); II is the enzyme electrode response at the same thiocholine 229
concentration plus a given inhibitor concentration. 230
A simple and versatile technique for enzyme immobilisation based on gold-thiol 231
chemistry is the spontaneous chemisorption of the sulphur-containing organic compound 232
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(cysteamine, mercaptobenzothiazole, etc.) on the colloid gold-modified electrode surfaces, 233
thereby forming a self-assembled monolayer, SAM, to which the AChE enzyme is attached 234
through intermolecular complexes (Du et al., 2008, 2009; Liu & Lin, 2006; Pedrosa et al., 235
2007; Somerset et al., 2009). This immobilisation approach provides conformational 236
flexibility of the enzyme and hence assures a more efficient biocatalytic process, albeit 237
enabling the formation of a thicker diffusion layer that reduces electrode sensitivity. An even 238
simpler method for AChE immobilisation is to chemisorb it directly on the surface of Au NPs 239
without the need for additional thiolated linkers (Du et al., 2007a, 2007b; Marinov et al., 240
2010; Shulga & Kirchhoff, 2007), since its protein shell contains terminal SH-groups. The 241
obvious challenge in this case, however, entails retaining the enzyme-functionalised NPs on 242
the electrode, which is implemented by either their incorporation in a porous membrane 243
(Marinov et al., 2010) or by inclusion in a composite film cast on the surface of the working 244
electrode (Du et al., 2007a, 2007b), thereby yielding a stable but thick catalytic layer that 245
triggers additional diffusion limitations. Direct growth of Au NPs on the surface of a compact 246
graphite electrode through electrodeposition allows for a much better electrical contact 247
between the two conductive materials, resulting in a much improved electrode sensitivity 248
towards thiocholine (Dimcheva et al., 2013a). Self-assembly of the AChE enzyme to the Au 249
NPs thus deposited yielded a membrane-free and, hence, fast-responding AChE-based 250
biosensor with a storage stability exceeding one month. 251
252
253
Direct electron transfer promoted by metal nanoparticles and its application in third-254
generation biosensors 255
256
The role of metal nanosized particles in third-generation biosensors is much more 257
complex, since it is believed that, in many cases, they promote the direct electron transfer 258
(DET) process between the electrode and the enzyme active site by shortening the distance 259
between them or by orienting the enzyme upon its immobilisation (Liu et al., 2003; Pingarrón 260
et al., 2008). The most systematically DET-promoting abilities of Au NPs have been explored 261
in relation to the development of cathodes for the enzymatic biofuel cells bearing multi-262
copper oxidases–laccases (Brondani et al., 2013; Krikstolaityte et al., 2014; Rahman et al., 263
2008) or bilirubin oxidases (Mano & Edembe, 2013; Pita et al., 2013), as catalysts for ORR 264
(oxygen reduction reaction). 265
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Some of the earlier reports on the direct electrochemistry promoted by the 266
nanoparticles of noble metals concerned haem-containing redox proteins such as myoglobin 267
(Dimcheva et al., 2011; Liu & Ju, 2003), haemoglobin (Zhao et al., 2006) and the larger 268
molecule of the peroxidase enzyme (Di et al., 2005). Catalase also belongs to the haem-269
containing enzymes; it consists of four sub-units forming a tetramer with the huge molecular 270
mass of 275 kDa and its active site was found to be buried deep in the protein shell; all these 271
conditions suggest the electrochemical inactivity of the enzyme. Huang et al. (2011), 272
however, observed direct electrochemistry and electrocatalysis with catalase immobilised on 273
an Au NPs-amine-functionalised graphene composite, most probably due to the reduced 274
distance between the enzyme active centre and the electrode. In all of the examples discussed 275
above, where the direct electrochemistry of haem-containing proteins/enzymes was 276
established, it was further used to construct third-generation amperometric biosensors for 277
H2O2. 278
Although glucose oxidase, a flavoprotein with the active site placed deeply inside the 279
protein globule, is considered to be electrochemically inactive, several recent studies have 280
reported on its direct electrochemistry and electrocatalysis applicable in third-generation 281
glucose biosensors (Cui et al., 2014; Haghighi & Tabrizi, 2013; Holland et al., 2011; Liu & 282
Huang, 2012; Palanisamy et al., 2014; Ragupathy et al., 2009; Xu et al., 2012; Yu et al., 283
2014). In connection with this, a very successful strategy to greatly increase the biosensor 284
sensitivity towards its substrate (glucose) by electrically wiring the enzyme via highly ordered 285
nanostructures has been developed by Adeloju and co-workers (Cui et al., 2014; Xu et al., 286
2012). Their glucose nanobiosensor arrays exhibited extraordinary operational characteristics 287
(Cui et al., 2014), e.g. a limit of detection below 1 µM and a linear dynamic range spanning 288
three orders of magnitude (5–6000 µM) and the capacity to respond interference-free to 289
glucose in real samples. 290
Another interesting example of a flavoenzyme believed to be electrochemically inert, 291
but exhibiting direct electrochemistry when immobilised on metal NPs-modified electrodes, is 292
cholesterol oxidase (Karimi et al., 2012; Zhu et al., 2013). Similarly, third-generation 293
cholesterol biosensors demonstrate low limits of detection, high sensitivity and excellent 294
selectivity towards the analyte of interest. 295
Au NPs were found to be useful in promoting DET processes even for the more 296
complex oxidative enzyme – the two-domain sulphite oxidase (Frasca et al., 2012). The 297
strong electrocatalytic effect on the oxidation of sulphite was the basis for constructing a fast-298
responding and highly sensitive third-generation sulphite biosensor. Analogously, direct 299
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electrochemistry and electrocatalysis by chemisorbed ascorbate oxidase (a multi-copper 300
oxidase, MCO) triggered by Au NPs-modified electrodes was recently reported by our group 301
(Dimcheva et al., 2013b; Dodevska et al., 2013). It is generally believed that two-substrate 302
MCOs only work for third-generation biosensors towards oxygen reduction, due to the 303
internal electron transfer between the three active centres of these enzymes, and that they can 304
eventually oxidise their second substrate (bilirubin, phenols or L-ascorbate) solely under de-305
oxygenated conditions. The AOx enzyme chemisorbed on Au NPs, however, demonstrates 306
the somewhat unusual ability to work for the third-generation L-ascorbate biosensor even 307
under oxygenated conditions. It is possible that a part of the enzyme binds to the Au NPs in 308
close proximity to the ascorbate-linking site (T1), thereby creating a shortcut between it and 309
the underlying electrode which renders the internal electron transport a less favourable 310
pathway. Comparing the electrode response towards L-ascorbate in the absence and in the 311
presence of oxygen, it may be estimated that approximately 1/3 of the enzyme chemisorbs 312
onto the Au NPs in this unusual conformation. Comparative experiments have shown that, on 313
a flat solid gold electrode, the AOx enzyme chemisorbs, shows the ability to 314
electrochemically reduce oxygen, but does not electrocatalytically oxidise L-ascorbate under 315
aerated conditions (Dimcheva et al., 2014). 316
317
318
Conclusions 319
320
In brief, the most beneficial feature of the micro-/nanoparticles-modified transducers, 321
in view of the development of first-generation amperometric biosensors, is their 322
electrocatalytic activity towards the target compound, which is an electroactive either reagent 323
or product of the enzyme-catalysed process. In addition, when the modifiers are Au NPs or Pt 324
NPs, the nanostructures may serve as anchors to which the biocatalyst is attached, largely 325
using the gold–thiol or platinum–thiol chemistry. 326
DET is an exclusive feature of the oxidative enzymes/proteins: their active sites 327
consist of either metal clusters (e.g. Fe/S or Cu clusters) or redox molecules (haemin, FAD, 328
NADH, PQQ), which are buried in the protein shell. Achieving the direct electrochemistry of 329
the enzyme and electrocatalysis in the presence of its typical substrate is the necessary 330
prerequisite to construct third-generation biosensors with exclusive selectivity and greatly 331
improved operational characteristics. Metal NPs or MPs may trigger these two events or may 332
even provoke some unexpected modifications of the electrocatalytic activity. 333
11
334
335
Acknowledgements. The authors gratefully acknowledge the financial support received 336
from the Bulgarian National Science Fund (grant no. DVU-02/38) and the technical help 337
received from the student, Boris Dzhuvinov (Computer Science, University of Plovdiv). 338
339
340
References 341
342
Aili, D., & Liedberg, B. (2010). Biomimetic approaches to self-assembly of nanomaterials. In 343
C. S. S. R. Kumar (Ed.), Biomimetic and bioinspired nanomaterials (Series: Nanomaterials 344
for the life sciences, Chapter 10, pp. 343–377). Weinheim, Germany: Wiley-VCH. DOI: 345
10.1002/9783527610419.ntls0212. 346
Alexeyeva, N., Laaksonen, T., Kontturi, K., Mirkhalaf, F., Schiffrin, D. J., & Tammeveski, K. 347
(2006). Oxygen reduction on gold nanoparticle/multi-walled carbon nanotubes modified 348
glassy carbon electrodes in acid solution. Electrochemistry Communications, 8, 1475–1480. 349
DOI: 10.1016/j.elecom.2006.07.002. 350
Arduini, F., Amine, A., Moscone, D., & Palleschi, G. (2010). Biosensors based on 351
cholinesterase inhibition for insecticides, nerve agents and aflatoxin B1 detection (review). 352
Microchimica Acta, 170, 193–214. DOI: 10.1007/s00604-010-0317-1. 353
Batra, B., & Pundir, C. S. (2013). An amperometric glutamate biosensor based on 354
immobilization of glutamate oxidase onto carboxylated multiwalled carbon nanotubes/gold 355
nanoparticles/chitosan composite film modified Au electrode. Biosensors and 356
Bioelectronics, 47, 496–501. DOI: 10.1016/j.bios.2013.03.063. 357
Bharathi, S., & Lev, O. (1997). Direct synthesis of gold nanodispersions in sol–gel derived 358
silicate sols, gels and films. Chemical Communications, 1997, 2303–2304. DOI: 359
10.1039/a705609e. 360
Bron, M. (2008). Carbon black supported gold nanoparticles for oxygen electroreduction in 361
acidic electrolyte solution. Journal of Electroanalytical Chemistry, 624, 64–68. DOI: 362
10.1016/j.jelechem.2008.07.026. 363
Brondani, D., de Souza, B., Souza, B. S., Neves, A., & Vieira, I. C. (2013). PEI-coated gold 364
nanoparticles decorated with laccase: A new platform for direct electrochemistry of enzymes 365
and biosensing applications. Biosensors and Bioelectronics, 42, 242–247. DOI: 366
10.1016/j.bios.2012.10.087. 367
12
Chandrasekharan, N., & Kamat, P. V. (2001). Assembling gold nanoparticles as 368
nanostructured films using an electrophoretic approach. Nano Letters, 1, 67–70. DOI: 369
10.1021/nl000184f. 370
Charmantray, F., Touisni, N., Hecquet, L., & Mousty, C. (2013). Amperometric biosensor 371
based on galactose oxidase immobilized in clay matrix. Electroanalysis, 25, 630–635. DOI: 372
10.1002/elan.201200274. 373
Chauhan, N., Narang, J., Sunny, & Pundir, C. S. (2013). Immobilization of lysine oxidase on 374
a gold–platinum nanoparticles modified Au electrode for detection of lysine. Enzyme and 375
Microbial Technology, 52, 265–271. DOI: 10.1016/j.enzmictec.2013.01.006. 376
Chikae, M., Idegami, K., Kerman, K., Nagatani, N., Ishikawa, M., Takamura, Y., & Tamiya, 377
E. (2006). Direct fabrication of catalytic metal nanoparticles onto the surface of a screen-378
printed carbon electrode. Electrochemistry Communications, 8, 1375–1380. DOI: 379
10.1016/j.elecom.2006.06.019. 380
Choi, H. N., Han, J. H., Park, J. A., Lee, J. M., & Lee, W. Y. (2007). Amperometric glucose 381
biosensor based on glucose oxidase encapsulated in carbon nanotube–titania–Nafion 382
composite film on platinized glassy carbon electrode. Electroanalysis, 19, 1757–1763. DOI: 383
10.1002/elan.200703958. 384
Comba, F. N., Rubianes, M. D., Herrasti, P., & Rivas, G. A. (2010). Glucose biosensing at 385
carbon paste electrodes containing iron nanoparticles. Sensors and Actuators B: Chemical, 386
149, 306–309. DOI: 10.1016/j.snb.2010.06.020. 387
Crespilho, F. N., Iost, R. M., Travain, S. A., Oliveira, O. N., Jr., & Zucolotto, V. (2009). 388
Enzyme immobilization on Ag nanoparticles/polyaniline nanocomposites. Biosensors and 389
Bioelectronics, 24, 3073–3077. DOI: 10.1016/j.bios.2009.03.026. 390
Cui, J., Adeloju, S. B., & Wu, Y. (2014). Integration of a highly ordered gold nanowires array 391
with glucose oxidase for ultra-sensitive glucose detection. Analytica Chimica Acta, 809, 392
134–140. DOI: 10.1016/j.aca.2013.11.024. 393
Dai, X., & Compton, R. G. (2006). Direct electrodeposition of gold nanoparticles onto indium 394
tin oxide film coated glass: Application to the detection of arsenic(III). Analytical Sciences, 395
22, 567–570. DOI: 10.2116/analsci.22.567. 396
de Dios, A. S., & Díaz-García, M. E. (2010). Multifunctional nanoparticles: Analytical 397
prospects. Analytica Chimica Acta, 666, 1–22. DOI: 10.1016/j.aca.2010.03.038. 398
Dhawan, G., Sumana, G., & Malhotra, B. D. (2009). Recent developments in urea biosensors. 399
Biochemical Engineering Journal, 44, 42–52. DOI: 10.1016/j.bej.2008.07.004. 400
13
Di, J., Shen, C., Peng, S., Tu, Y., & Li, S. (2005). A one-step method to construct a third-401
generation biosensor based on horseradish peroxidase and gold nanoparticles embedded in 402
silica sol–gel network on gold modified electrode. Analytica Chimica Acta, 553, 196–200. 403
DOI: 10.1016/j.aca.2005.08.013. 404
Dimcheva, N., Horozova, E., & Jordanova, Z. (2002a). An amperometric xanthine oxidase 405
enzyme electrode based on hydrogen peroxide electroreduction. Zeitschrift für 406
Naturforschung C – A Journal of Biosciences, 57c, 883–889. 407
Dimcheva, N., Horozova, E., & Jordanova, Z. (2002b). A glucose oxidase immobilized 408
electrode based on modified graphite. Zeitschrift für Naturforschung C – A Journal of 409
Biosciences, 57c, 705–711. 410
Dimcheva, N. D., Horozova, E. G., & Dodevska, T. M. (2011). Direct electrochemistry of 411
myoglobin immobilized on non-modified and modified graphite. Bulgarian Chemical 412
Communications, 43, 17–22. 413
Dimcheva, N., Horozova, E., Ivanov, Y., & Godjevargova, T. (2013a). Self-assembly of 414
acetylcholinesterase on gold nanoparticles electrodeposited on graphite. Central European 415
Journal of Chemistry, 11, 1740–1748. DOI: 10.2478/s11532-013-0307-3. 416
Dimcheva, N., Dodevska, T., & Horozova, E. (2013b). Direct electrochemistry of ascorbate 417
oxidase self-assembled on Au-modified glassy carbon. Journal of the Electrochemical 418
Society, 160, H414–H419. DOI: 10.1149/2.025308jes. 419
Dimcheva, N., Horozova, E., & Dodevska, T. (2014). Electrochemical activity of two redox 420
biocatalysts promoted by gold nanostructures: A proof of principle and applications in 421
biosensing. In Book of Abstracts of the 8th National Conference on Chemistry: Chemistry 422
for Sustainable Development, June 26–28, 2014 (pp. 11-O7). Sofia, Bulgaria: University of 423
Chemical Technology and Metallurgy. 424
Do, J. S., Lin, K. H., & Ohara, R. (2011). Preparation of urease/nano-structured polyaniline-425
Nafion®/Au/Al2O3 electrode for inhibitive detection of mercury ion. Journal of the Taiwan 426
Institute of Chemical Engineers, 42, 662–668. DOI: 10.1016/j.jtice.2010.11.007. 427
Dobbs, W., Suisse, J. M., Douce, L., & Welter, R. (2006). Electrodeposition of silver particles 428
and gold nanoparticles from ionic liquid-crystal precursors. Angewandte Chemie, 118, 4285–429
4288. DOI: 10.1002/ange.200600929. 430
Dodevska, T., Horozova, E., & Dimcheva, N. (2006). Electrocatalytic reduction of hydrogen 431
peroxide on modified graphite electrodes: Application to the development of glucose 432
biosensors. Analytical and Bioanalytical Chemistry, 386, 1413–1418. DOI: 10.1007/s00216-433
006-0682-0. 434
14
Dodevska, T., Horozova, E., & Dimcheva, N. (2010). Design of an amperometric xanthine 435
biosensor based on a graphite transducer patterned with noble metal microparticles. Central 436
European Journal of Chemistry, 8, 19–27. DOI: 10.2478/s11532-009-0102-3. 437
Dodevska, T., Horozova, E., & Dimcheva, N. (2013). Electrochemical behavior of ascorbate 438
oxidase immobilized on graphite electrode modified with Au-nanoparticles. Materials 439
Science and Engineering B: Solid-State Materials for Advanced Technology, 178, 1497–440
1502. DOI: 10.1016/j.mseb.2013.08.012. 441
Doria, G., Conde, J., Veigas, B., Giestas, L., Almeida, C., Assunção, M., Rosa, J., & Baptista, 442
P. V. (2012). Noble metal nanoparticles for biosensing applications. Sensors, 12, 1657–443
1687. DOI: 10.3390/s120201657. 444
Du, D., Ding, J., Cai, J., & Zhang, A. (2007a). Electrochemical thiocholine inhibition sensor 445
based on biocatalytic growth of Au nanoparticles using chitosan as template. Sensors and 446
Actuators B: Chemical, 127, 317–322. DOI: 10.1016/j.snb.2007.04.023. 447
Du, D., Huang, X., Cai, J., & Zhang, A. (2007b). Amperometric detection of triazophos 448
pesticide using acetylcholinesterase biosensor based on multiwall carbon nanotube–chitosan 449
matrix. Sensors and Actuators B: Chemical, 127, 531–535. DOI: 10.1016/j.snb.2007.05.006. 450
Du, D., Chen, W., Cai, J., Zhang, J., Qu, F., & Li, H. (2008). Development of 451
acetylcholinesterase biosensor based on CdTe quantum dots modified cysteamine self-452
assembled monolayers. Journal of Electroanalytical Chemistry, 623, 81–85. DOI: 453
10.1016/j.jelechem.2008.06.020. 454
Du, D., Chen, W., Cai, J., Zhang, J., Tu, H., & Zhang, A. (2009). Acetylcholinesterase 455
biosensor based on gold nanoparticles and cysteamine self assembled monolayer for 456
determination of monocrotophos. Journal of Nanoscience and Nanotechnology, 9, 2368–457
2373. DOI: 10.1166/jnn.2009.se24. 458
El-Deab, M. S., & Ohsaka, T. (2002a). An extraordinary electrocatalytic reduction of oxygen 459
on gold nanoparticles-electrodeposited gold electrodes. Electrochemistry Communications, 460
4, 288–292. DOI: 10.1016/s1388-2481(02)00263-1. 461
El-Deab, M. S., & Ohsaka, T. (2002b). Hydrodynamic voltammetric studies of the oxygen 462
reduction at gold nanoparticles-electrodeposited gold electrodes. Electrochimica Acta, 47, 463
4255–4261. DOI: 10.1016/s0013-4686(02)00487-5. 464
El-Deab, M. S., & Ohsaka, T. (2003). Electrocatalysis by nanoparticles: oxygen reduction on 465
gold nanoparticles-electrodeposited platinum electrodes. Journal of Electroanalytical 466
Chemistry, 553, 107–115. DOI: 10.1016/s0022-0728(03)00291-2. 467
15
El-Deab, M. S., Sotomura, T., & Ohsaka, T. (2005a). Oxygen reduction at electrochemically 468
deposited crystallographically oriented Au(1 0 0)-like gold nanoparticles. Electrochemistry 469
Communications, 7, 29–34. DOI: 10.1016/j.elecom.2004.10.010. 470
El-Deab, M. S., Sotomura, T., & Ohsaka, T. (2005b). Morphological selection of gold 471
nanoparticles electrodeposited on various substrates. Journal of the Electrochemical Society, 472
152, C730–C737. DOI: 10.1149/1.2041948. 473
El-Deab, M. S., Sotomura, T., & Ohsaka, T. (2005c). Size and crystallographic orientation 474
controls of gold nanoparticles electrodeposited on GC electrodes. Journal of the 475
Electrochemical Society, 152, C1–C6. DOI: 10.1149/1.1824041. 476
El-Deab, M. S., & Ohsaka, T. (2006). Electrocatalytic reduction of oxygen at Au 477
nanoparticles–manganese oxide nanoparticle binary catalysts. Journal of the 478
Electrochemical Society, 153, A1365–A1371. DOI: 10.1149/1.2196707. 479
El-Deab, M. S., Sotomura, T., & Ohsaka, T. (2006). Oxygen reduction at Au nanoparticles 480
electrodeposited on different carbon substrates. Electrochimica Acta, 52, 1792–1798. DOI: 481
10.1016/j.electacta.2005.12.057. 482
El-Deab, M. S., & Ohsaka, T. (2007). Electrocatalysis by design: Effect of the loading level 483
of Au nanoparticles–MnOx nanoparticles binary catalysts on the electrochemical reduction 484
of molecular oxygen. Electrochimica Acta, 52, 2166–2174. DOI: 485
10.1016/j.electacta.2006.08.041. 486
El-Deab, M. S. (2009). On the preferential crystallographic orientation of Au nanoparticles: 487
Effect of electrodeposition time. Electrochimica Acta, 54, 3720–3725. DOI: 488
10.1016/j.electacta.2009.01.054. 489
El-Deab, M. S. (2010). Electrocatalysis by nanoparticles: Oxidation of formic acid at 490
manganese oxide nanorods-modified Pt planar and nanohole-arrays. Journal of Advanced 491
Research, 1, 87–93. DOI: 10.1016/j.jare.2010.01.001. 492
El-Nagar, G. A., Mohammad, A. M., El-Deab, M. S., & El-Anadouli, B. E. (2013). 493
Electrocatalysis by design: Enhanced electrooxidation of formic acid at platinum 494
nanoparticles–nickel oxide nanoparticles binary catalysts. Electrochimica Acta, 94, 62–71. 495
DOI: 10.1016/j.electacta.2013.01.133. 496
Erikson, H., Jürmann, G., Sarapuu, A., Potter, R. J., & Tammeveski, K. (2009). 497
Electroreduction of oxygen on carbon-supported gold catalysts. Electrochimica Acta, 54, 498
7483–7489. DOI: 10.1016/j.electacta.2009.08.001. 499
16
Frasca, S., Rojas, O., Salewski, J., Neumann, B., Stiba, K., Weidinger, I. M., Tiersch, B., 500
Leimkühler, S., Koetz, J., & Wollenberger, U. (2012). Human sulfite oxidase 501
electrochemistry on gold nanoparticles modified electrode. Bioelectrochemistry, 87, 33–41. 502
DOI: 10.1016/j.bioelechem.2011.11.012. 503
Freeman, R. G., Hommer, M. B., Grabar, K. C., Jackson, M. A., & Natan, M. J. (1996). Ag-504
clad Au nanoparticles: Novel aggregation, optical, and surface-enhanced Raman scattering 505
properties. The Journal of Physical Chemistry, 100, 718–724. DOI: 10.1021/jp951379s. 506
Freestone, I., Meeks, N., Sax, M., & Higgitt, C. (2007). The Lycurgus Cup – a Roman 507
nanotechnology. Gold Bulletin, 40, 270–277. DOI: 10.1007/bf03215599. 508
Fu, C., Zhou, H., Xie, D., Sun, L., Yin, Y., Chen, J., & Kuang, Y. (2010). Electrodeposition 509
of gold nanoparticles from ionic liquid microemulsion. Colloid and Polymer Science, 288, 510
1097–1103. DOI: 10.1007/s00396-010-2238-2. 511
Gao, F., El-Deab, M. S., Okajima, T., & Ohsaka, T. (2005). Electrochemical preparation of a 512
Au crystal with peculiar morphology and unique growth orientation and its catalysis for 513
oxygen reduction. Journal of the Electrochemical Society, 152, A1226–A1232. DOI: 514
10.1149/1.1906023. 515
Gartia, M. R., Hsiao, A., Pokhriyal, A., Seo, S., Kulsharova, G., Cunningham, B. T., Bond, T. 516
C., & Liu, G. L. (2013). Colorimetric plasmon resonance imaging using nano Lycurgus Cup 517
arrays. Advanced Optical Materials, 1, 68–76. DOI: 10.1002/adom.201200040. 518
Ghindilis, A. L., Atanasov, P., & Wilkins, E. (1997). Enzyme-catalyzed direct electron 519
transfer: Fundamentals and analytical applications. Electroanalysis, 9, 661–674. DOI: 520
10.1002/elan.1140090902. 521
Ghosh, S. K., & Pal, T. (2007). Interparticle coupling effect on the surface plasmon resonance 522
of gold nanoparticles: From theory to applications. Chemical Reviews, 107, 4797–4862. 523
DOI: 10.1021/cr0680282. 524
Gloaguen, F., Léger, J. M., Lamy, C., Marmann, A., Stimming, U., & Vogel, R. (1999). 525
Platinum electrodeposition on graphite: electrochemical study and STM imaging. 526
Electrochimica Acta, 44, 1805–1816. DOI: 10.1016/s0013-4686(98)00332-6. 527
Gorton, L., Lindgren, A., Larsson, T., Munteanu, F. D., Ruzgas, T., & Gazaryan, I. (1999). 528
Direct electron transfer between heme-containing enzymes and electrodes as basis for third 529
generation biosensors. Analytica Chimica Acta, 400, 91–108. DOI: 10.1016/s0003-530
2670(99)00610-8. 531
17
Haghighi, B., & Tabrizi, M. A. (2013). Direct electron transfer from glucose oxidase 532
immobilized on an overoxidized polypyrrole film decorated with Au nanoparticles. Colloids 533
and Surfaces B: Biointerfaces, 103, 566–571. DOI: 10.1016/j.colsurfb.2012.11.010. 534
Holland, J. T., Lau, C., Brozik, S., Atanassov, P., & Banta, S. (2011). Engineering of glucose 535
oxidase for direct electron transfer via site-specific gold nanoparticle conjugation. Journal of 536
the American Chemical Society, 133, 19262–19265. DOI: 10.1021/ja2071237. 537
Horozova, E. G., Dimcheva, N. D., & Jordanova, Z. J. (2000). Study of xanthine oxidase 538
immobilized electrode based on modified graphite. Zeitschrift für Naturforschung C – A 539
Journal of Biosciences, 55c, 60–65. 540
Horozova, E., Dodevska, T., & Dimcheva, N. (2009). Modified graphites: Application to the 541
development of enzyme-based amperometric biosensors. Bioelectrochemistry, 74, 260–264. 542
DOI: 10.1016/j.bioelechem.2008.09.003. 543
Hsu, S. Y., Bartling, B., Wang, C., Shieu, F. S., & Liu, C. C. (2010). Enzymatic determination 544
of diglyceride using an iridium nano-particle based single use, disposable biosensor. 545
Sensors, 10, 5758–5773. DOI: 10.3390/s100605758. 546
Huang, K. J., Niu, D. J., Liu, X., Wu, Z. W., Fan, Y., Chang, Y. F., & Wu, Y. Y. (2011). 547
Direct electrochemistry of catalase at amine-functionalized graphene/gold nanoparticles 548
composite film for hydrogen peroxide sensor. Electrochimica Acta, 56, 2947–2953. DOI: 549
10.1016/j.electacta.2010.12.094. 550
Ilias, S. H., Kok, K. Y., Ng, I. K., & Saidin, N. U. (2013). Electrochemical synthesis and 551
characterization of palladium nanostructures. Journal of Physics: Conference Series, 431. 552
012003. DOI: 10.1088/1742-6596/431/1/012003. 553
Ishikawa, H., Ida, T., & Kimura, K. (1996). Plasmon absorption of gold nanoparticles and 554
their morphologies observed by AFM. Surface Review and Letters, 3, 1153–1156. DOI: 555
10.1142/s0218625x96002060. 556
IUPAC (2005–2014). IUPAC compendium of chemical terminology – gold book. Version 557
2.3.3 (2014-02-24). Research Triangle Park, NC, USA International Union of Pure and 558
Applied Chemistry. DOI: 10.1351/goldbook. 559
Jäckel, F., & Feldmann, J. (2012). Surface-enhanced Raman scattering using complex-shaped 560
metal nanostructures In T. K. Sau & A. L. Rogach (Eds.), Complex-shaped metal 561
nanoparticles: Bottom-up syntheses and applications (Chapter 13, pp. 429–454). Weinheim, 562
Germany: Wiley-VCH. DOI: 10.1002/9783527652570.ch13. 563
Jia, W., Su, L., & Lei, Y. (2011). Pt nanoflower/polyaniline composite nanofibers based urea 564
biosensor. Biosensors and Bioelectronics, 30, 158–164. DOI: 10.1016/j.bios.2011.09.006. 565
18
Karimi, S., Ghourchian, H., Rahimi, P., & Rafiee-Pour, H. A. (2012). A nanocomposite based 566
biosensor for cholesterol determination. Analytical Methods, 4, 3225–3231. DOI: 567
10.1039/c2ay25826a. 568
Karyakin, A. A. (2001). Prussian blue and its analogues: Electrochemistry and analytical 569
applications. Electroanalysis, 13, 813–819. DOI: 10.1002/1521-570
4109(200106)13:10<813::AID-ELAN813>3.0.CO;2-Z. 571
Kirwan, S. M., Rocchitta, G., McMahon, C. P., Craig, J. D., Killoran, S. J., O’Brien, K. B., 572
Serra, P. A., Lowry, J. P., & O’Neill, R. D. (2007). Modifications of poly(o-573
phenylenediamine) permselective layer on Pt-Ir for biosensor application in neurochemical 574
monitoring. Sensors, 7, 420–437. DOI: 10.3390/s7040420. 575
Krasnansky, R., Yamamura, S., Thomas, J. K., & Dellaguardia, R. (1991). Photoproduction of 576
gold colloids and films. Langmuir, 7, 2881–2886. DOI: 10.1021/la00060a003. 577
Krikstolaityte, V., Barrantes, A., Ramanavicius, A., Arnebrant, T., Shleev, S., & Ruzgas, T. 578
(2014). Bioelectrocatalytic reduction of oxygen at gold nanoparticles modified with laccase. 579
Bioelectrochemistry, 95, 1–6. DOI: 10.1016/j.bioelechem.2013.09.004. 580
Lim, S. H., Wei, J., Lin, J., Li, Q., & You, J. K. (2005). A glucose biosensor based on 581
electrodeposition of palladium nanoparticles and glucose oxidase onto Nafion-solubilized 582
carbon nanotube electrode. Biosensors and Bioelectronics, 20, 2341–2346. DOI: 583
10.1016/j.bios.2004.08.005. 584
Lima, F. H. B., Profeti, D., Chatenet, M., Riello, D., Ticianelli, E. A., & Gonzalez, E. R. 585
(2010). Electro-oxidation of ethanol on Rh/Pt and Ru/Rh/Pt sub-monolayers deposited on 586
Au/C nanoparticles. Electrocatalysis, 1, 72–82. DOI: 10.1007/s12678-010-0014-1. 587
Liu, S., & Ju, H. (2003). Electrocatalysis via direct electrochemistry of myoglobin 588
immobilized on colloidal gold nanoparticles. Electroanalysis, 15, 1488–1493. DOI: 589
10.1002/elan.200302722. 590
Liu, S., Leech, D., & Ju, H. (2003). Application of colloidal gold in protein immobilization, 591
electron transfer, and biosensing. Analytical Letters, 36, 1–19. DOI: 10.1081/al-120017740. 592
Liu, G., & Lin, Y. (2006). Biosensor based on self-assembling acetylcholinesterase on carbon 593
nanotubes for flow injection/amperometric detection of organophosphate pesticides and 594
nerve agents. Analytical Chemistry, 78, 835–843. DOI: 10.1021/ac051559q. 595
Liu, A. R., & Huang, S. M. (2012). A glucose biosensor based on direct electrochemistry of 596
glucose oxidase immobilized onto platinum nanoparticles modified graphene electrode. 597
Science China - Physics, Mechanics & Astronomy, 55, 1163–1167. DOI: 10.1007/s11433-598
012-4782-x. 599
19
Luo, X., Morrin, A., Killard, A. J., & Smyth, M. R. (2006). Application of nanoparticles in 600
electrochemical sensors and biosensors. Electroanalysis, 18, 319–326. DOI: 601
10.1002/elan.200503415. 602
Ma, Y., Di, J., Yan, X., Zhao, M., Lu, Z., & Tu, Y. (2009). Direct electrodeposition of gold 603
nanoparticles on indium tin oxide surface and its application. Biosensors and Bioelectronics, 604
24, 1480–1483. DOI: 10.1016/j.bios.2008.10.007. 605
Mano, N., & Edembe, L. (2013). Bilirubin oxidases in bioelectrochemistry: Features and 606
recent findings. Biosensors and Bioelectronics, 50, 478–485. DOI: 607
10.1016/j.bios.2013.07.014. 608
Mao, S., Long, Y., Li, W., Tu, Y., & Deng, A. (2013). Core–shell structured Ag@C for direct 609
electrochemistry and hydrogen peroxide biosensor applications. Biosensors and 610
Bioelectronics, 48, 258–262. DOI: 10.1016/j.bios.2013.04.026. 611
Marinov, I., Ivanov, Y., Gabrovska, K., & Godjevargova, T. (2010). Amperometric 612
acetylthiocholine sensor based on acetylcholinesterase immobilized on nanostructured 613
polymer membrane containing gold nanoparticles. Journal of Molecular Catalysis B: 614
Enzymatic, 62, 67–75. DOI: 10.1016/j.molcatb.2009.09.005. 615
Martorell, D., Céspedes, F., Martínez-Fàbregas, E., & Alegret, S. (1994). Amperometric 616
determination of pesticides using a biosensor based on a polishable graphite-epoxy 617
biocomposite. Analytica Chimica Acta, 290, 343–348. DOI: 10.1016/0003-2670(94)80121-618
5. 619
Marty, J. L., Mionetto, N., & Rouillon, R. (1992). Entrapped enzymes in photocrosslinkable 620
gel for enzyme electrodes. Analytical Letters, 25, 1389–1398. DOI: 621
10.1080/00032719208017123. 622
Marty, J. L., Mionetto, N., Lacorte, S., & Barceló, D. (1995). Validation of an enzymatic 623
biosensor with various liquid chromatographic techniques for determining 624
organophosphorus pesticides and carbaryl in freeze-dried waters. Analytica Chimica Acta, 625
311, 265–271. DOI: 10.1016/0003-2670(94)00617-u. 626
Mizsei, J., Sipilä, P., & Lantto, V. (1998). Structural studies of sputtered noble metal catalysts 627
on oxide surfaces. Sensors and Actuators B: Chemical, 47, 139–144. DOI: 10.1016/s0925-628
4005(98)00015-x. 629
Mizukoshi, Y., Okitsu, K., Maeda, Y., Yamamoto, T. A., Oshima, R., & Nagata, Y. (1997). 630
Sonochemical preparation of bimetallic nanoparticles of gold/palladium in aqueous solution. 631
The Journal of Physical Chemistry B, 101, 7033–7037. DOI: 10.1021/jp9638090. 632
20
Montornes, J. M., Vreeke, M. S., & Katakis, I. (2008). Glucose biosensors. In P. N. Bartlett 633
(Ed.), Bioelectrochemistry: Fundamentals, experimental techniques and applications 634
(Chapter 5, pp. 199–217). Chichester, UK: Wiley. DOI: 10.1002/9780470753842.ch5. 635
Nagaiah, T. C., Schäfer, D., Schuhmann, W., & Dimcheva, N. (2013). Electrochemically 636
deposited Pd-Pt and Pd-Au codeposits on graphite electrodes for electrocatalytic H2O2 637
reduction. Analytical Chemistry, 85, 7897–7903. DOI: 10.1021/ac401317y. 638
Olivia, H., Sarada, B. V., Honda, K., & Fujishima, A. (2004). Continuous glucose monitoring 639
using enzyme-immobilized platinized diamond microfiber electrodes. Electrochimica Acta, 640
49, 2069–2076. DOI: 10.1016/j.electacta.2003.10.026. 641
Palanisamy, S., Karuppiah, C., & Chen, S. M. (2014). Direct electrochemistry and 642
electrocatalysis of glucose oxidase immobilized on reduced graphene oxide and silver 643
nanoparticles nanocomposite modified electrode. Colloids and Surfaces B: Biointerfaces, 644
114, 164–169. DOI: 10.1016/j.colsurfb.2013.10.006. 645
Pandey, P. C., Upadhyay, S., Pathak, H. C., Pandey, C. M. D., & Tiwari, I. (2000). 646
Acetylthiocholine/acetylcholine and thiocholine/choline electrochemical biosensors/sensors 647
based on an organically modified sol–gel glass enzyme reactor and graphite paste electrode. 648
Sensors and Actuators, B: Chemical, 62, 109–116. DOI: 10.1016/s0925-4005(99)00367-6. 649
Pedrosa, V. A., Caetano, J., Machado, S. A. S., Freire, R. S., & Bertotti, M. (2007). 650
Acetylcholinesterase immobilization on 3-mercaptopropionic acid self assembled monolayer 651
for determination of pesticides. Electroanalysis, 19, 1415–1420. DOI: 652
10.1002/elan.200703872. 653
Pingarrón, J. M., Yáñez-Sedeño, P., & González-Cortés, A. (2008). Gold nanoparticle-based 654
electrochemical biosensors. Electrochimica Acta, 53, 5848–5866. DOI: 655
10.1016/j.electacta.2008.03.005. 656
Pita, M., Gutierrez-Sanchez, C., Toscano, M. D., Shleev, S., & De Lacey, A. L. (2013). 657
Oxygen biosensor based on bilirubin oxidase immobilized on a nanostructured gold 658
electrode. Bioelectrochemistry, 94, 69–74. DOI: 10.1016/j.bioelechem.2013.07.001. 659
Plyasova, L. M., Molina, I. Y., Gavrilov, A. N., Cherepanova, S. V., Cherstiouk, O. V., 660
Rudina, N. A., Savinova, E. R., & Tsirlina, G. A. (2006). Electrodeposited platinum 661
revisited: Tuning nanostructure via the deposition potential. Electrochimica Acta, 51, 4477–662
4488. DOI: 10.1016/j.electacta.2005.12.027. 663
Qiaocui, S., Tuzhi, P., Yunu, Z., & Yang, C. F. (2005). An electrochemical biosensor with 664
cholesterol oxidase/sol-gel film on a nanoplatinum/carbon nanotube electrode. 665
Electroanalysis, 17, 857–861. DOI: 10.1002/elan.200403162. 666
21
Quinn, B. M., Dekker, C., & Lemay, S. G. (2005). Electrodeposition of noble metal 667
nanoparticles on carbon nanotubes. Journal of the American Chemical Society, 127, 6146–668
6147. DOI: 10.1021/ja0508828. 669
Ragupathy, D., Gopalan, A. I., & Lee, K. P. (2009). Synergistic contributions of multiwall 670
carbon nanotubes and gold nanoparticles in a chitosan–ionic liquid matrix towards improved 671
performance for a glucose sensor. Electrochemistry Communications, 11, 397–401. DOI: 672
10.1016/j.elecom.2008.11.048. 673
Rahman, M. A., Noh, H. B., & Shim, Y. B. (2008). Direct electrochemistry of laccase 674
immobilized on Au nanoparticles encapsulated-dendrimer bonded conducting polymer: 675
Application for a catechin sensor. Analytical Chemistry, 80, 8020–8027. DOI: 676
10.1021/ac801033s. 677
Ramos, S. G., Moreno, M. S., Andreasen, G. A., & Triaca, W. E. (2010). Facetted platinum 678
electrocatalysts for electrochemical energy converters. International Journal of Hydrogen 679
Energy, 35, 5925–5929. DOI: 10.1016/j.ijhydene.2009.12.106. 680
Sau, T. K., & Rogach, A. L. (2012). Colloidal synthesis of noble metal nanoparticles of 681
complex morphologies. In T. K. Sau, & A. L. Rogach (Eds.), Complex-shaped metal 682
nanoparticles: Bottom-up syntheses and applications (Chapter 1, pp. 7–90). Weinheim, 683
Germany: Wiley-VCH. 10.1002/9783527652570.ch1. 684
Sekol, R. C., Li, X., Cohen, P., Doubek, G., Carmo, M., & Taylor, A. D. (2013). Silver 685
palladium core–shell electrocatalyst supported on MWNTs for ORR in alkaline media. 686
Applied Catalysis B: Environmental, 138–139, 285–293. DOI: 687
10.1016/j.apcatb.2013.02.054. 688
Shao, M., Odell, J. H., Choi, S. I., & Xia, Y. (2013). Electrochemical surface area 689
measurements of platinum- and palladium-based nanoparticles. Electrochemistry 690
Communications, 31, 46–48. DOI: 10.1016/j.elecom.2013.03.011. 691
Shulga, O., & Kirchhoff, J. R. (2007). An acetylcholinesterase enzyme electrode stabilized by 692
an electrodeposited gold nanoparticle layer. Electrochemistry Communications, 9, 935–940. 693
DOI: 10.1016/j.elecom.2006.11.021. 694
Singh, M., Verma, N., Garg, A. K., & Redhu, N. (2008). Urea biosensors. Sensors and 695
Actuators B: Chemical, 134, 345–351. DOI: 10.1016/j.snb.2008.04.025. 696
Somerset, V., Baker, P., & Iwuoha, E. (2009). Mercaptobenzothiazole-on-gold organic phase 697
biosensor systems: 1. Enhanced organosphosphate pesticide determination. Journal of 698
Environmental Science and Health, Part B: Pesticides, Food Contaminants, and 699
Agricultural Wastes, 44, 164–178. DOI: 10.1080/03601230802599092. 700
22
Stoytcheva, M., Sharkova, V., & Magnin, J. P. (1998). Electrochemical approach in studying 701
the inactivation of immobilized acetylcholinesterase by arsenate(III). Electroanalysis, 10, 702
994–998. DOI: 10.1002/(SICI)1521-4109(199810)10:14<994::AID-ELAN994>3.0.CO;2-0. 703
Tang, J., Tian, X. C., Pang, W. H., Liu, Y. Q., & Lin, J. H. (2012). Codeposition of AuPd 704
bimetallic nanoparticles on to ITO and their electrocatalytic properties for ethanol oxidation. 705
Electrochimica Acta, 81, 8–13. DOI: 10.1016/j.electacta.2012.07.048. 706
Terauchi, S., Koshizaki, N., & Umehara, H. (1995). Fabrication of Au nanoparticles by radio-707
frequency magnetron sputtering. Nanostructured Materials, 5, 71–78. DOI: 10.1016/0965-708
9773(95)00011-3. 709
Tiwari, A., Aryal, S., Pilla, S., & Gong, S. (2009). An amperometric urea biosensor based on 710
covalently immobilized urease on an electrode made of hyperbranched polyester 711
functionalized gold nanoparticles. Talanta, 78, 1401–1407. DOI: 712
10.1016/j.talanta.2009.02.038. 713
Turkevich, J., Stevenson, P. C., & Hillier, J. (1951). A study of the nucleation and growth 714
processes in the synthesis of colloidal gold. Discussions of the Faraday Society, 11, 55–75. 715
DOI: 10.1039/df9511100055. 716
Turkevich, J., Stevenson, P. C., & Hillier, J. (1953). The formation of colloidal gold. The 717
Journal of Physical Chemistry, 57, 670–673. DOI: 10.1021/j150508a015. 718
Turkevich, J., & Kim, G. (1970). Palladium: Preparation and catalytic properties of particles 719
of uniform size. Science, 169, 873–879. 720
Velichkova, Y., Ivanov, Y., Marinov, I., Ramesh, R., Kamini, N. R., Dimcheva, N., 721
Horozova, E., & Godjevargova, T. (2011). Amperometric electrode for determination of urea 722
using electrodeposited rhodium and immobilized urease. Journal of Molecular Catalysis B: 723
Enzymatic, 69, 168–175. DOI: 10.1016/j.molcatb.2011.01.015. 724
Wang, L., Mao, W., Ni, D., Di, J., Wu, Y., & Tu, Y. (2008). Direct electrodeposition of gold 725
nanoparticles onto indium/tin oxide film coated glass and its application for electrochemical 726
biosensor. Electrochemistry Communications, 10, 673–676. DOI: 727
10.1016/j.elecom.2008.02.009. 728
Wang, J., Wang, L., Di, J., & Tu, Y. (2009). Electrodeposition of gold nanoparticles on 729
indium/tin oxide electrode for fabrication of a disposable hydrogen peroxide biosensor. 730
Talanta, 77, 1454–1459. DOI: 10.1016/j.talanta.2008.09.034. 731
Whyman, R. (1996). Gold nanoparticles: A renaissance in gold chemistry. Gold Bulletin, 29, 732
11–15. DOI: 10.1007/bf03214736. 733
23
Wilson, R. (2008). The use of gold nanoparticles in diagnostics and detection. Chemical 734
Society Reviews, 37, 2028–2045. DOI: 10.1039/b712179m. 735
Xu, G., Adeloju, S. B., Wu, Y., & Zhang, X. (2012). Modification of polypyrrole nanowires 736
array with platinum nanoparticles and glucose oxidase for fabrication of a novel glucose 737
biosensor. Analytica Chimica Acta, 755, 100–107. DOI: 10.1016/j.aca.2012.09.037. 738
Xue, B., Chen, P., Hong, Q., Lin, J., & Tan, K. L. (2001). Growth of Pd, Pt, Ag and Au 739
nanoparticles on carbon nanotubes. Journal of Materials Chemistry, 11, 2378–2381. DOI: 740
10.1039/b100618p. 741
Yang, M., Qu, F., Lu, Y., He, Y., Shen, G., & Yu, R. (2006). Platinum nanowire 742
nanoelectrode array for the fabrication of biosensors. Biomaterials, 27, 5944–5950. DOI: 743
10.1016/j.biomaterials.2006.08.014. 744
Yu, Y., Chen, Z., He, S., Zhang, B., Li, X., & Yao, M. (2014). Direct electron transfer of 745
glucose oxidase and biosensing for glucose based on PDDA-capped gold nanoparticle 746
modified graphene/multi-walled carbon nanotubes electrode. Biosensors and Bioelectronics, 747
52, 147–152. DOI: 10.1016/j.bios.2013.08.043. 748
Zhang, X., Cao, Y., Yu, S., Yang, F., & Xi, P. (2013). An electrochemical biosensor for 749
ascorbic acid based on carbon-supported PdNi nanoparticles. Biosensors and Bioelectronics, 750
44, 183–190. DOI: 10.1016/j.bios.2013.01.020. 751
Zhao, S., Zhang, K., Sun, Y., & Sun, C. (2006). Hemoglobin/colloidal silver nanoparticles 752
immobilized in titania sol–gel film on glassy carbon electrode: Direct electrochemistry and 753
electrocatalysis. Bioelectrochemistry, 69, 10–15. DOI: 10.1016/j.bioelechem.2005.09.004. 754
Zhao, K., Zhuang, S., Chang, Z., Songm, H., Dai, L., He, P., & Fang, Y. (2007). 755
Amperometric glucose biosensor based on platinum nanoparticles combined aligned carbon 756
nanotubes electrode. Electroanalysis, 19, 1069–1074. DOI: 10.1002/elan.200603823. 757
Zhu, L., Xu, L., Tan, L., Tan, H., Yang, S., & Yao, S. (2013). Direct electrochemistry of 758
cholesterol oxidase immobilized on gold nanoparticles-decorated multiwalled carbon 759
nanotubes and cholesterol sensing. Talanta, 106, 192–199. DOI: 760
10.1016/j.talanta.2012.12.036. 761
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Table 1. First-generation amperometric biosensors with H2O2 electrocatalytic reduction as response-generating process 765
766
Analyte Immobilised enzyme Electrode modifier Ea/V Reference
Glucose Glucose oxidase Pd/Pt alloys (MPs) 0 Dimcheva et al. (2002b); Dodevska et al. (2006); Nagaiah et al. (2013)
Pt nanowires 0 Yang et al. (2006)
Fe NPs −0.1 Comba et al. (2010)
Pt NPs −0.1 Choi et al. (2007)
Pd NPs n.a. Lim et al. (2005)
Cholesterol Cholesterol oxidase CNT + Pt NPs n.a. Qiaocui et al. (2005)
Glutamate Glutamate oxidase Au NPs 0.135 Batra and Pundir (2013)
L-Lysine L-Lysine oxidase Au NPs + Pt NPs 0.2 Chauhan et al. (2013)
Xanthine Xanthine oxidase Pd/Pt alloys (MPs) −0.05 Dodevska et al. (2010); Horozova et al. (2009)
a) All operating potentials (E) were measured against Ag/AgCl; n.a. means not available. 767
768
