Stream2A-Smartphonediagnostics,wearablebiosensorsandmobilehealth10:15-11:45Tuesday,27thJuly,2021PresentationtypeOralMun'delanjiC.Vestergaard,Dae-HyeongKim

10:15-10:30

O2A.01 Lubricin(PRG4):Aversatileproteinforelectrochemicalsensing

SaimonM.Silva1,M.Russo2,A.F.Quigley3,R.M.I.Kapsa4,G.W.Greene2,S.E.Moulton11SwinburneUniversityofTechnology,Australia.2DeakinUniversity,Australia.3RoyalMelbourneInstituteofTechnology,Australia.4UniversityofWollongong,Australia

Abstract

Lubricin(LUB;a.k.a.PRG4)isacytoprotectiveglycoproteinexistinginthesynovialfluidsandcoatingcartilagesurfacesinmammalianarticularjoints.LUBpresentsadistinctivechemistry,molecularandconformationalstructure,aswellasthecapabilityofself-assemblinginawell-organizedmanneronpracticallyanysubstrate,whichmakesitaninterestingsurfacecoatingforbiologicalapplications[1].Whentetheredtoaconductivesurface,LUBcanpreventbiofoulingandenablegoodelectrochemistrywiththeadvantageofasimpleandone-stepcoatingpreparation[2].ThisworkaimstoinvestigatetheantifoulingpropertiesofLUBimmobilizedontodifferentsubstrates(i.e.metalsandcarbon-basedelectrodes)aswellasitsversatilityforelectrochemicalsensing.TheanalyticalperformanceofLUBcoatingstowardsdirectdetectionofbarbituratedrugsinsalivasamplesandrelevantbiologicalmoleculesinwholebloodisalsoinvestigated.IthasbeenshownthatthesizeselectivityofLUBcoatingsinhibitthenon-specificadsorptionoflargebiomoleculeswhilesimultaneouslyallowingsmallerredoxactivemoleculessuchasferricyanidetoreachtheelectrodesurface(Figure1).OurstudiesshowedthattheLUBcoatingscouldpreventnon-specificadsorptionoflargerproteinssuchasbovineandhumanserumalbuminsevenwhenthepreparedsurfaces(LUBtetheredtogold,platinum,carbon-based,orITOelectrodes)arechallengedinhigh-concentrationproteinsolutions.Next,weshowtheversatilityoflubricinforperformingdirectanalyticalquantificationofbarbituratesdrugsinunprocessedcomplexbiologicalmatricessuchassalivausingsquare-wavevoltammetryasexcitationtechnique.Thefindingspresentedhere,showsthegreatpotentialofusingLUBcoatingsinprotein-basedelectrochemicalformonitoringofdrugslevelsinapoint-of-caresetting.

Figure1-Schematicillustratingthesize-selectivetransportpropertiesoftheLUBself-assembledmonolayer.[1]M.Han,S.M.Silva,W.Lei,A.F.Quigley,R.M.Kapsa,S.E.Moulton,G.W.Greene,AdhesionandSelf-AssemblyofLubricin(PRG4)BrushLayersonDifferentSubstrateSurfaces.Langmuir(2019)Inpress.[2]S.M.Silva,A.F.Quigley,R.M.Kapsa,G.W.Greene,S.E.Moulton,LubricinonPlatinumElectrodes:ALow‐ImpedanceProtein‐ResistantSurfaceTowardsBiomedicalImplantation,6(2019)1939-1943.

10:30-10:45

O2A.02 Instrument-freevoltammetryusingamobilephone

C.F.Hogan,D.Elton,P.O'ConghaileLaTrobeUniversity,Australia

Abstract

Recenttrendsinthefieldofchemicalsensorsandbiosensorshavehighlightedtheimportanceofsimplicityandlowcostindeterminingwhetherasensingtechnologyhasthecapacitytobeinanywaytransformativetothelivesofordinarypeople,particularlythoseinresource-poororremoteenvironments.Anapproachwhichisgrowinginimportanceislinkingthesensingstrategytomobilephones,whichhavereachedmarketsaturationinthedevelopedworldandarerapidlyreachingthesamelevelofubiquityinthedevelopingworld.Electrochemicalmethodsaretotheforefrontofthistrend,andanumberofminiaturizedpotentiostats,whichhavetheabilitytointerfacewithamobiledevice,havebeendescribed.

Voltammetryisthecornerstonetechniqueofelectrochemicalsensing.Theabilitytoprovidenotonlysensitivequantitativeinformationfromthemagnitudeofthecurrentpeak,butalsoadegreeofselectivityofferedbythepotentialaxisofthevoltammogram,isthereasonvoltammetricmethodshaveenjoyedsuchenduringpopularity.Inthisworkwedemonstratehowelectrochemicalanalysis,specifically2ndharmonicFourierTransformedACvoltammetry,maybecarriedoutusingamobilesmartphoneortablet.Importantly,unlikeexistingapproaches,whereanelectronicmodule(suchasaminiaturisedpotentiostat),isconnectedtothephone,wehaveachievedthisusingonlythebuilt-inelectronicfeaturesofthephoneitselfandasoftwareapplication.Byusingtheaudiooutputoftheheadsetporttoapplyavoltageexcitationsignalandthemicrophoneinputlineofthesameporttomeasurethecurrent,avoltammogramcanbeproducedwhichremarkablycloselyresemblesthatproducedusingacommercialpotentiostat.Usingthisapproach,whichwecallAndroidvoltammetry,wedemonstrateseveralapplicationsintheareasofwinetesting,waterqualityanalysisandhealthtesting.

10:45-11:00

O2A.03 DirectelectrontransfertypeL-lactatesensorforwearablemultiplexedbiosensorsystemtowardcontinuousmonitoringofmetabolitesinsweat

K.Hiraka1,S.Motohashi1,W.Tsugawa1,R.Asano1,M.A.Yokus2,K.Ikebukuro1,M.A.Daniele2,3,K.Sode3,21TokyoUniversityofAgricultureandTechnology,Japan.2NorthCarolinaStateUniversity,USA.3UniversityofNorthCarolinaatChapelHill,USA

Abstract

Introduction:Inthisstudy,wereportdirectelectrontransfer(DET)typeL-lactatesensoremployingengineeredDETtypeL-lactatedehydrogenase(DET-LDH)tobeintegratedintowearablemultiplexedbiosensorsystemforcontinuousmonitoringofmetabolitesinsweat.Intherecentdecade,non-invasivemetaboliteandelectrolytesensors,basedonsweatanalysis,hasbeenpaidgreatattention.Theauthorshavebeenengagedinthedevelopmentofanelectrodearray-basedflexiblesensorplatformintegratedwithalow-costmultiplexingsystemforsimultaneousdetectionofglucose,L-lactate,pH,andtemperature.Thewearablehardwareisaminiaturizedandinexpensivestand-alonesystem.Forthefurtherimprovementoftheenzymaticsensorperformance,theemploymentofDETprincipleisideal.AlthoughDETtypeglucosedehydrogenaseisreadytobecombinedintothisplatform,thelactatesensorisstillsufferingfromtheavailabilityofDETtypeLDH.Here,wepresentourefforttorealizeDET-basedL-lactatemonitoring,bythedevelopmentofanengineeredLDH,whichiscapableofDET,anditsorientationontheelectrodeiscontrollable.Methods:TheengineeredDET-LDH,harbouringHemebastheelectrontransferdomain,wasfurtherengineeredbyfusingcarbonnanotubebindingpeptide(CNTBP)toregulateitsorientationontheelectrode.ToevaluatetheabilityforDET,chronoamperometryinvestigationwascarriedout(Ag/AgClasareferenceandexternalPtasacounterelectrode),andcurrentincreasewasmonitoredbyapplying+150mVvs.Ag/AgClwithsuccessiveadditionofL-lactate.ResultsandDiscussion:CatalyticcurrentwasobservedaftertheadditionofL-lactate,andtheresponsecurrentincreaseddependingonlactateconcentrationatengineeredLDH,whichwasmuchhigherthantheonewithoutCNTBP.TheseresultssuggestedthatthusdevelopedDETtypeL-lactatesensorcouldbeintegratedintothewearableflexibleelectrodeplatformtoachievenon-invasiveandcontinuousmonitoringofsweatL-lactatewithoutanyartificialelectronmediator.

11:00-11:15

O2A.04 MouthguardglucosesensorwithPrussianblueasanelectron-transfermediatorforreductionofinfluenceofsalivarycontaminants

T.Arakawa,Z.Zhang,K.Tomoto,K.Toma,K.MitsubayashiTokyoMedicalandDentalUniversity,Japan

Abstract

Wehavedevelopedamouthguardbiosensorfornon-invasivemonitoringofsalivaryglucose.AsalivarybiosensorbasedontheintegrationofPtandAg/AgClelectrodeswithanenzymemembraneonamouthguardwasfabricatedanddemonstrated.ThismouthguardbiosensorwasintegratedwithaglucosebiosensorwithPrussianblueasanelectron-transfermediatorandwirelessmeasurementsystem(Bluetooth4.0module).Intheinvestigationofin-vitrocharacterization,thebiosensorshowedexcellentrelationshipbetweentheoutputcurrentandtheglucoseconcentration.Inartificialsalivaconsistingofsaltsandproteins,theglucosesensorexhibitshigh-sensitiveandhigh-selectivedetectioninarangeof1-5000µmol/Lglucose.Stableandlong-termmonitoring(morethan2hours)usingtelemetrysystemwasestablished.Themouthguardbiosensorcouldbeusefulandconvenientmonitoringasanovelmanagementofglucose.Fig.1showsfabricatedmouthguardglucosesensorwithtelemetrysystemondentalmodelbasedonMEMSfabricationtechnique.Theglucosesensorresponsewasdependentonglucoseconcentration.Outputcurrentimmediatelyincreasedwheneachglucosesolutioninjectedandreachedsteady-statevaluessoonafterthestartofeach180secondinterval.Glucoseconcentration(dynamicrange1-5000µM)wasstronglycorrelatedwithmeanΔoutputcurrentincludingconcentrationofsalivaryglucoseinhuman(Fig.2left).Whenglucosewasmeasuredinartificialsalivausinganappliedpotentialof+100mV,aclearincreaseinoutputduetoglucosewasnotconfirmed.Prussianblue(PB)-Ptelectrodeasanelectronmediator,wasexaminedinordertomeasureglucoseatalowpotential.CVcharacteristicsofhydrogenperoxideinartificialsalivawereinvestigatedusingPB-Ptelectrodespreparedbyelectroplating.ComparedwiththePtelectrode,thePB-Ptelectrodeobtainedthepeakvalueofthereductioncurrentattheappliedlowpotentialvolatageof+5mV.ItwaspossibletomeasureGlucoseatalowappliedpotentialwithoutinfluenceofascorbicacidanduricacid(Fig.2right).Wealsodemonstratedthecapabilityofthesensorandwirelesscommunicationmoduletomonitorsalivaglucoseinaphantommandiblereplicatingtheenvironmentofthehumanoralcavity.Stableresponseswithinapproximately60secondswereobtainedwhenchangingfrom0.05to1.0mmol/L.

Fig.1SchematicimageandphotoofmouthguardglucosesensorwithBluetoothlowenergytelemetrysystemondentalmodel.Fig.2(Left)Calibrationcurveforglucosesensor(n=5).(Insetgraph)Responseofglucosesensorto1–5000µmol/Lglucosesolution.(Right)Responsetoglucose,ascorbicacidanduricacidusingglucosesensor.

11:15-11:30

O2A.05 Aflexiblepolyanilinebiosensorarrayformulti-channelcardiovascularhealthmonitoring

V.P.Rachim,S.Kang,J.H.Baek,S.M.ParkPohangUniversityofScienceandTechnology,RepublicofKorea

Abstract

Continuousmonitoringofthekeycardiovascularparameterssuchaspulserate(PR),bodytemperature,andbloodpressure(BP)playanimportantroleinawiderangeofhealthcareapplicationsfromthelifestylerecommendation,tothepreventionofdiseases.Amongmanyparameters,pulsewavehasbeenidentifiedasaversatiledigitalphenotypeandavarietyofdeviceshavebeendevelopedforaccuratemeasurementofthepulsewave.Recentadvancementsinflexibleelectronicshaveenabledthedevelopmentofhighlysensitiveandstretchablewearablesensorsthatcansupporttheneedsofunobstructive,mobilehealthmonitoringsystem.However,mostoftheestablishedstudiesonlyfocusonasinglewavemonitoringwhichisnotenoughforthecompletecardiovascularanalysis,yetadditionalsensorusuallyneededwhichmakestheoverallsystempower-hungry.Therefore,wedevelopaflexible,low-power,patch-typebiosensorarrayusingaconductivepolymer,polyaniline(PANI)materialtomeasurepulsewavebydetectingthedeformationoftheskinscausedbythebloodvesselvolumechange.Inparticular,weenableamulti-channelcardiovascularmonitoringfromonlyasinglemeasurementsite,subjectwrist,bydesigninga3x2arrayofPANIsensor(multiPANI).Inthisstudy,theproposedmultiPANIconfigurationisutilizedforsignalqualityassessmentandcuff-lessBPestimation.Firstly,amultiplepulsewavesarecollectedfromthemultiPANI,thusthisredundantsignalsareusedasmotionartifactsreductionforhigh-qualitypulsewaveandbetterPRdetection.Secondly,thepulsetransittime(PTT)methodisappliedtocalculatetheBPfromthetimeintervalbetweenthespecificreferencepointsofthetwosignalsofthemultiPANI.ThemultiplePTTdelaybetweendifferenttwo-channelconfigurationisobservedconcerningthechangeofBPvalue.Inconclusion,ourstudysuggeststhattheproposedmultiPANIisapromisingsolutionforafullynon-obstructive,low-power,andcontinuousmulti-cardiovascularparametermonitoring.

Figure1.FlexibleMultiPANIbiosensorforfullynon-obstructive,low-power,andcontinuousmulti-

cardiovascularparametermonitoring.a)PhotographofMultiPANIattachedtoawrist.b)Illustrationoftheusageofmulti-channelpulsewavesignalforsignalqualityassessmentandcuff-lessBPestimation.

11:30-11:45

O2A.06 SurfaceresonancebasedRFsensorforglucosemappinginaqueoussolutions

J.Malik1,2,F.Bien1,21SB-SolutionsInc.,RepublicofKorea.2UlsanNationalInstituteofScienceandTechnology,RepublicofKorea

Abstract

Introduction:Earlier,surfaceplasmonresonance(SPP)basedbiosensorsarewellrecognizedfortheiraccuracyandhighsensitivitytowardsbio-moleculedetection[1].However,theSPPbasedsensorsrequiresophisticatedexperimentalsetupoperatingatsubterahertztoTHzfrequencyregime.Radiofrequency(RF)basedbiosensorsarenowadaysubiquitousinbiomedicaldiagnosisaswellasawiderangeofapplicationssuchaspoint-of-caremonitoring,biomedicalsensing(e.g.heartrate),invivotrackingetc.Inthiswork,wepresentasurfaceresonancebasedRFsensorfordetectionandmappingofglucosecontentinaqueousglucosesolution.Thesensorisintendedtobeusedasbodyimplantsensorforbloodglucosemonitoringfrominterstitialfluid.Thesensoroperatesatindustrialscientificmedical(ISM)band,andcanbeintegratedwithminiaturestate-of-theartintegratedcircuittechnology.Sensorwithultra-highQfactorresonanceyieldshighersensitivityduetoitssharpresonance,withsignificantfrequencyshiftaccordingtoaminutechangeofanalytepermittivity.ThehighQvalueresonancemodescanbeobtainedintrappedmodesorsub-radiativemodeswithFanolikeresonance.Theseresonancessupporthigherordermodes,whichispossibleinapreciseelectromagnetictailoredmetamaterial[2].Methods:BioTissuehasbeenmodelasDebyedielectricmodelwithdispersivecharacteristics.Theresonancefrequencydoesnotaffectedbythethicknessofthesurroundingbiotissuethickness.Thismodelisconsideredfortheactualscenariothatmimicsbodydielectricconstantsincewateroccupiesalargestportionofblood.Results:CalculatedweightofD-glucose(GR1009-500-00)wasmixedin100mlofdeionizedwatertoproducetheaqueousglucosesolutionswithdifferentconcentrations.Thesolutionswerestirredusingmagneticstirrertoachieveahomogeneousglucosesolution.Thetemperatureofthesolutionwastrackedusingathermometer(CASFT-500).

(a)(b)Fig.1(a)sensormodellingandfabricatedprototype(b)measuredsensitivitywithglucosesolutionThesensorwastestedwithglucosesolutionwithdifferentconcentration.Thesurfaceofthesensorissensitivetowardsdielectricchangearoundthesensor.Thesensitivityintermsofresonanceminimumwasprecisely

trackedwithavectornetworkanalyser.Theresonancefrequencyshiftobservedaninverserelationwithincreasingglucoselevel.Discussion:ThepresentsurfaceresonancebasedRFsensorcanmonitorbloodglucosefrominterstitialfluid.Fortheproofofconcept,experimentalmeasurementswithaqueousglucosesolutionshowsgoodsensitivitytowardsglucoselevelchange.Thesensorissupercompact(4mmdiameter,17mmlength,0.071gramweight)tobeusedasanimplantsensorcapableofcontinuousbloodglucosemonitoring.References:[1]SabineSzuneritsandRabahBoukherroub,SensingusinglocalisedsurfaceplasmonresonancesensorsChem.Commun.,2012,48,8999–9010.[2]JagannathMaliketal.,Electromagneticallyinducedtransparencyinsinusoidalmodulatedringresonator,Appl.Phys.Lett.112,234102,2018.