o A highly sensitive and stable glucose biosensor using thymine-based polycations into laponite hydrogel films

VERÓNICA I. PAZ ZANINI; MAXIMILIANO GAVILAN ; DÉBORA MARTINO; CLAUDIO D. BORSARELLI; BEATRIZ A. LOPEZ DE MISHIMA

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 150 p. 646 - 654

0039-9140

A seriesofglucosebioelectrodeswerepreparedbyglucoseoxidase(GOx)immobilizationintolaponitehydrogel films containingDNAbioinspiredpolycationsmadeofvinylbenzylthymine(VBT)andvi-nylbenzyltriethylammoniumchloride(VBA)withgeneralformulae [( ) ()]≈VBT + VBA m nn25 with m¼0, 1andn¼2, 4,8,depositedontoglassycarbonelectrode.Thebioelectrodeswerecharacterizedbychron-oamperometry,cyclicvoltammetryandelectrochemicalimpedancespectroscopy.Resultsindicatedthatthe electrochemicalpropertiesofthelaponitehydrogel films werelargelyimprovedbytheincorporationof thymine-basedpolycations,beingproportionaltothepositivechargedensityofthepolycationmo-lecule. Afterincorporationofglucoseoxidase,thesensitivityofthebioelectrodetoglucoseincreasedwith thepositivechargedensityofthepolycation.Additionally,thepresenceofthevinylbenzylthyminemoiety playedaroleinthelong-termstabilityandreproducibilityofthebioelectrodesignal.Asacon-sequence,the [( )()]≈VBT + VBA 8 258 wasthemostappropriatepolycationforbioelectrodepreparationandglucose sensing,withaspecific sensitivityof se¼176mAmmol1 L cm2 U1, almosttwo-orderofmagnitude largerthanotherlaponiteimmobilizedGOxbioelectrodesreportedelsewhere.Thesefeatureswereconfirmed bytestingthebioelectrodeforaselectivedeterminationofglucoseinpowdermilkandblood serumsampleswithoutinterferenceofeitherascorbicoruricacidsundertheexperimentalconditions.The presentstudydemonstratesthesuitabilityofDNAbioinspiredwater-solublepolycations[( ) ()]≈VBT + VBA m nn25 for enzymeimmobilizationlikeGOxintolaponitehydrogels,andthepreparationofhighly sensitiveandstablebioelectrodesonglassycarbonsurface.