Nanostructuring platinum nanoparticles on multilayered graphene petal nanosheets for electrochemical biosensing

Abstract

Hybridization of nanoscale metals and carbon nanotubes into composite nanomaterials has produced some of the best-performing sensors to date. The challenge remains to develop scalable nanofabrication methods that are amenable to the development of sensors with broad sensing ranges. A scalable nanostructured biosensor based on multilayered graphene petal nanosheets (MGPNs), Pt nanoparticles, and a biorecognition element (glucose oxidase) is presented. The combination of zero-dimensional nanoparticles on a two-dimensional support that is arrayed in the third dimension creates a sensor platform with exceptional characteristics. The versatility of the biosensor platform is demonstrated by altering biosensor performance (i.e., sensitivity, detection limit, and linear sensing range) through changing the size, density, and morphology of electrodeposited Pt nanoparticles on the MGPNs. This work enables a robust sensor design that demonstrates exceptional performance with enhanced glucose sensitivity (0.3 μM detection limit, 0.01-50 mM linear sensing range), a long stable shelf-life (>1 month), and a high selectivity over electroactive, interfering species commonly found in human serum samples. A controllable electrochemical deposition technique is used to deposit Pt nanoparticles of varying size and density onto multilayered graphene petal nanosheets (MGPNs). The Pt/MGPNs are converted to glucose biosensors by electrodepositing the enzyme glucose oxidase with the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) onto the electrode surface. The glucose linear sensing range is optimized by varying the Pt nanoparticle size and density. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.