基于L-半胱氨酸/纳米金固定酶的过氧化氢生物传感器

将L-半胱氨酸电聚合于金电极表面,通过静电作用和共价结合,吸附带负电荷的纳米金(nano-Au),最后再利用纳米金吸附固定过氧化物酶(HRP),制备了一种新型层层自组装的电流型过氧化氢(H2O2)传感器.采用交流阻抗和计时电流法对该传感器的性能进行了详细研究.实验表明,该传感器增加了酶的吸附量,响应快、稳定性好,对H2O2表现出良好的响应特性.在0.1 mol/L PBS(pH值6.5)缓冲溶液中,电位为0.3 V的实验条件下,该传感器对H2O2检测范围为3.5×10-6～5.9×10-3 mol/L,检测下限为9.6×10-7 mol/L(S/N=3).

Hydrogen Peroxide Biosensor Based on Immobilized Enzyme of L-cysteine/Gold Nanoparticles

Based on the immobility of horseradish peroxidase(HRP) with nano-Au,a novel hydrogen peroxide biosensor was fabricated by layer-by-layer self-assembling.L-cysteine,which could adsorb nano-Au via electrostatic and covalent action,was firstly modified on Au electrode via electric aggregation and then the assembled nano-Au on the surface of Au electrode could immobilize HRP to fabricate the proposed biosensor.The performance and factors influencing the biosensor were studied in detail by means of alternating current impedance and chronoamperometry.The immobilized HRP biosensor increased the adsorption amount of euzyme,and for hydrogen peroxide(H2O2) it showed fast response and good stability in the electrochemical behavior.The linear range of H2O2 was from 3.5×10-6 to 5.9×10-3 mol/L,and the detection limit was 9.6×10-7 mol/L(S/N=3) in the condtion of 0.1 mol/L PBS buffer solution(pH 6.5) and 0.3 V voltage.