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Abstract
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tA novel and efficient glucose biosensor based on the chemiluminescence (CL) detection of enzymat-ically generated H2O2was constructed by the effective immobilization of glucose oxidase (GOX) onthe Fe3O4–chitosan (Fe3O4–CS) nanoparticles support. The covalent immobilization of enzyme was per-formed using glutheraldehyde (GA) as a cross-linking agent. (H2O2was constructed by one covalentimmobilization of glucose oxidase in glutaraldehyde-functionalized glass cell). In addition to catalyzesthe luminol CL reaction, gold NPs offer excellent catalytic activity toward hydrogen peroxide generation asa result of enzymatic reaction between glucose oxidase and glucose. Based on response surface method-ology (RSM), the optimal immobilization conditions for glucose oxidase were obtained as: enzyme tosupport ratio, 0.7; Immobilization pH, 6; cross-linking time, 75 min; and glutaraldehyde (GA) concen-tration, 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 × 10−4to 8.5 × 10−7mol L−1(R2= 0.9956). Thedetection limit is 4.3 × 10−7mol L−1. The relative standard deviation (RSD) <3.1% was obtained.
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