Direct electrochemistry of glucose oxidase and biosensing for glucose based on boron-doped carbon-coated nickel modified electrode

A novel biosensor for detecting glucose had been constructed by the immobilization of glucose oxidase (GOD) on chitosan-boron-doped carbon-coated nickel (BCNi) nanoparticle modified electrode. The GOD-chitosan-BCNi bionanocomposite film was characterized with scanning electron microscope (SEM). The film was propitious to the immobilization of GOD and to the retention of its bioactivity. The direct electrochemistry and electrocatalysis of GOD on modified electrode had been investigated by cyclic voltammogram (CV) and amperometric measurements. The GOD displayed a pair of stable, well-defined and quasi-reversible redox peaks in pH 7.0 phosphate buffer solution (PBS). Furthermore, the biosensor was applied to detect glucose with a broad linear range from 2.50 × 10−5 to 1.19 × 10−3 M, the detection limit was brought down to 8.33 × 10−6 M at a signal to noise ratio of 3 and with an applied potential of −0.2 V. The proposed biosensor showed rapid response (within 3 s), low detection limit, high affinity to glucose and accepted storage stability over one-month period, which demonstrated that the chitosan-BCNi film has potential applications in the immobilization of other third-generation enzyme biosensors.