Suárez, GuillaumeSantschi, ChristianPlateel, GregoryMartin, Olivier J. F.Riediker, Michael2014-02-042014-02-042014-02-04201410.1016/j.bios.2013.12.063https://infoscience.epfl.ch/handle/20.500.14299/100353WOS:000333781000031A genericopticalbiosensingstrategywasdevelopedthatreliesontheabsorbanceenhancementphenom- enon occurringinamultiplescatteringmatrix.Experimentally,insertsmadeofglass fiber membranewere placedintomicroplatewellsinordertosignificantlylengthenthetrajectoryoftheincidentlightthroughthe sampleandthereforeincreasethecorrespondingabsorbance.Enhancementfactorwascalculatedby comparingtheabsorbancevaluesmeasuredforagivenamountofdyewithandwithouttheabsorbance- enhancinginsertsinthewells.Moreover,thedilutionofdyeinsolutionswithdifferentrefractiveindices(RI) clearlyrevealedthattheenhancementfactorincreasedwiththe ΔRI betweenthemembraneandthe surroundingmedium,reachingamaximumvalue(EF425)whenthemembranesweredried.Onthisbasis, two H2O2-biosensingsystemsweredevelopedbasedonthebiofunctionalizationoftheglass fiberinserts either withcytochrome c or horseradishperoxidase(HRP)andthe analyticalperformancesweresystem- aticallycomparedwiththecorrespondingbioassayinsolution.Theefficiencyoftheabsorbance-enhancement approachwasparticularlyclearinthecaseofthecytochrome c-basedbiosensorwithasensitivitygainof40 folds andwiderdynamicrange.Therefore,thedevelopedstrategyrepresentsapromisingwaytoconvert standardcolorimetricbioassaysintoopticalbiosensorswithimprovedsensitivity.NanophotonicsPlasmonicstext::journal::journal article::research article