title: Zinc oxide-potassium ferricyanide composite thin film matrix for biosensing applications.
abstract: Thin film of zinc oxide-potassium ferricyanide (ZnO-KFCN) composite has been deposited on indium tin oxide (ITO) coated corning glass using pulsed laser deposition (PLD). The composite thin film electrode has been exploited for amperometric biosensing in a mediator-free electrolyte. The composite matrix has the advantages of high iso-electric point of ZnO along with enhanced electron communication due to the presence of a redox species in the matrix itself. Glucose oxidase (GOx) has been chosen as the model enzyme for studying the application of the developed matrix to biosensing. The sensing response of the bio-electrode, GOx/ZnO-KFCN/ITO/glass, towards glucose was studied using cylic voltammetry (CV) and photometric assay. The bio-electrode exhibits good linearity from 2.78 mM to 11.11 mM glucose concentration. The low value of Michaelis-Menten constant (1.69 mM) indicates an enhanced affinity of the immobilized enzyme towards its substrate. A quassireversible system is obtained with the composite matrix. The results confirm promising application of the ZnO-KFCN composite matrix for amperometric biosensing applications in a mediator-less electrolyte that could lead to the realization of an integrated lab-on-chip device.
authors.affiliation: Department of Physics & Astrophysics, University of Delhi, Delhi 110007, India.
authors.forename: Shibu
authors.initials: S
authors.lastname: Saha
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Arya
authors.forename: S P
authors.initials: SP
authors.lastname: Singh
authors.forename: K
authors.initials: K
authors.lastname: Sreenivas
authors.forename: B D
authors.initials: BD
authors.lastname: Malhotra
authors.forename: Vinay
authors.initials: V
authors.lastname: Gupta
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry; D004566:Electrodes; D005292:Ferricyanides / Q000737:chemistry*; D005898:Glass / Q000737:chemistry; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D008567:Membranes, Artificial; D010783:Photometry; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D005292:Ferricyanides; D008567:Membranes, Artificial; D017971:Tin Compounds; C109984:indium tin oxide; D005949:Glucose Oxidase; D005947:Glucose; D015034:Zinc Oxide; C028033:potassium ferricyanide