Construction and Characterization of a Chitosan-Immobilized-Enzyme and β-Cyclodextrin-Included-Ferrocene-Based Electrochemical Biosensor for H 2 O 2 Detection

摘要

An electrochemical detection biosensor was prepared with the chitosan-immobilized-enzyme (CTS-CAT) and β-cyclodextrin-included-ferrocene (β-CD-FE) complex for the determination of H 2 O 2 . Ferrocene (FE) was included in β-cyclodextrin (β-CD) to increase its stability. The structure of the β-CD-FE was characterized. The inclusion amount, inclusion rate, and electrochemical properties of inclusion complexes were determined to optimize the reaction conditions for the inclusion. CTS-CAT was prepared by a step-by-step immobilization method, which overcame the disadvantages of the conventional preparation methods. The immobilization conditions were optimized to obtain the desired enzyme activity. CTS-CAT/β-CD-FE composite electrodes were prepared by compositing the CTS-CAT with the β-CD-FE complex on a glassy carbon electrode and used for the electrochemical detection of H 2 O 2 . It was found that the CTS-CAT could produce a strong reduction peak current in response to H 2 O 2 and the β-CD-FE could amplify the current signal. The peak current exhibited a linear relationship with the H 2 O 2 concentration in the range of 1.0 × 10 ?7 –6.0 × 10 ?3 mol/L. Our work provided a novel method for the construction of electrochemical biosensors with a fast response, good stability, high sensitivity, and a wide linear response range based on the composite of chitosan and cyclodextrin.