A novel glucose biosensor based on immobilization of glucose oxidase in chitosan on a glassy carbon electrode modified with gold platinum alloy nanoparticles/multiwall carbon nanotubes.
A novel glucose biosensor was constructed, based on the immobilization of glucose oxidase (GOx) with cross linking in the matrix of biopolymer chitosan (CS) on a glassy carbon electrode (GCE) which was modified with gold platinum alloy nanoparticles (Au PtNPs) by electrodeposition on multiwall carbon nanotubes (CNTs) in CS film (CNTs/CS) The properties of Au PtNPs/CNTs/CS were characterized by scan electron microscopy (SEM) X ray diffraction (XRD) cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) Primary study indicated that Au PtNPs/CNTs had a better synergistic electrocatalytic effect on the reduction of hydrogen peroxide than did AuNPs/CNTs or PtNPs/CNTs at a low applied potential window. With GOx as a model enzyme, a new glucose biosensor was fabricated. The biosensor exhibited excellent performances for glucose at a low applied potential (0.1V) with a high sensitivity (8.53 microA mM( 1) a low detection limit (0.2 microM) a wide linear range (0.001 7.0 mM) a fast response time <5s) and good reproducibility, stability, and selectivity. In addition, the biosensor was applied in the determination of glucose in human blood and urine samples, and satisfied results were obtained.
Analytical biochemistry