Absorbance enhancement in microplate wells for improved-sensitivity biosensors

A 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.


Published in:
Biosensors and Bioelectronics, 56, 198-203
Year:
2014
Publisher:
Oxford, Elsevier
ISSN:
0956-5663
Keywords:
Laboratories:




 Record created 2014-02-04, last modified 2018-09-13

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