A novel glucose sensor based on immobilization of glucose oxidase on the chitosan-coated Fe3O4 nanoparticles and the luminol–H2O2–gold nanoparticle chemiluminescence detection system

Abstract

A novel and efficient glucose biosensor based on the chemiluminescence (CL) detection of enzymatically generated H2O2 was constructed by the effective immobilization of glucose oxidase (GOX) on the Fe3O4–chitosan (Fe3O4–CS) nanoparticles support. The covalent immobilization of enzyme was performed using glutheraldehyde (GA) as a cross-linking agent. (H2O2 was constructed by one covalent immobilization of glucose oxidase in glutaraldehyde-functionalized glass cell). In addition to catalyzes the luminol CL reaction, gold NPs offer excellent catalytic activity toward hydrogen peroxide generation as a result of enzymatic reaction between glucose oxidase and glucose. Based on response surface methodology (RSM), the optimal immobilization conditions for glucose oxidase were obtained as: enzyme to support ratio, 0.7; Immobilization pH, 6; cross-linking time, 75min; and glutaraldehyde (GA) concentration, 0.2%. The characterization of Fe3O4, Fe3O4–chitosan and Au nanoparticles was analyzed by XRD, FT-IR and SEM. The linear range of this novel method is 1×10−4 to 8.5×10−7molL−1 (R2=0.9956). The detection limit is 4.3×10−7molL−1. The relative standard deviation (RSD) <3.1% was obtained.