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利用滴涂于金盘电极表面的 Nation 膜中负电性的磺酸基与 L-半胱氨酸阳离子之间的静电作用实现 L-半胱氨酸的固定化,然后利用 L-半胱氨酸表面的巯基吸附纳米金,荷负电的纳米金再结合 L-半胱氨酸阳离子后再吸附纳米金以制备基于多层分子自组装的辣根过氧化氢生物传感器。采用循环伏安法考察了传感器的电化学特性,用 Co(bpy)_3~(3+)作为电子媒介体,峰电流值与 H_2O_2浓度在2.5×10~(-5)～5.0×10~(-3)mol/L 成线性关系,检测下限为1.0×10~(-5)mol/L(S/N=3)。该传感器具有响应快、灵敏度高、稳定性好的性能,且具有良好的选择性,能有效排除抗坏血酸、抗尿酸等常见干扰物质对测定的影响。
L-cysteine was immobilized by the electrostatic interaction between the negatively charged sulfonic acid group and the L-cysteine cation in the Nation membrane dripped on the surface of the gold plate electrode. Then, L-cysteine Surface thiol adsorption of gold nanoparticles, negatively charged gold nanoparticles recombine with L-cysteine cation and then adsorbed gold nanoparticles to prepare multi-layer molecular self-assembly of horseradish hydrogen peroxide biosensors. The electrochemical properties of the sensor were investigated by cyclic voltammetry. Co (bpy) _3 ~ (3+) as the electron mediator, the peak current value and the concentration of H_2O_2 ranged from 2.5 × 10 ~ (-5) to 5.0 × 10 ~ -3) mol / L, the detection limit was 1.0 × 10 -5 mol / L (S / N = 3). The sensor has the characteristics of fast response, high sensitivity and good stability, and has good selectivity and can effectively eliminate the influence of common interfering substances such as ascorbic acid and anti-uric acid on the determination.