基于纳米金自组装膜固定辣根过氧化物酶的生物传感研究

Study of Biosensor Based Immobilized Horseradish Peroxidase on Nano-Au and Self-assembled Monolayers

将辣根过氧化物酶(HRP)通过纳米技术和自组装技术固定于电极表面,制得了酶修饰电极。纳米金与HRP形成了静电复合物并高效地保持了HRP的生物活性,以对苯二酚作为电子媒介体,差示脉冲伏安法(DPV)研究生物酶电极测定H2O2的线性范围为5.0×10-6～1.0×10-3 mol/L,检测限为2.5×10-6 mol/L,线性方程为△I=0.34765+4.05553CH2O2(mM)。酶电极的表观米氏常数(Kmapp)为0.0675 mmol/L。实验同时证明该生物酶电极具有良好的稳定性和使用寿命。

Enzyme modified electrode was prepared based immobilized horseradish peroxidase （HRP）on nano-Au and self-assembled monolayers. The presence of nano-Au in film can efficiently retain HRP activity since the formation of electrostatic complex of nano-Au-HRP. Hydrogen peroxide was determined in the presence of hydroquinone as a mediator to transfer electrons between the electrode and HRP. It was experimentally proved that HRP embedded on nano-Au demonstrated excellently electrocatalytical ability to the reduce of H2O2. The influences of experimental parameters on the response of H2O2 biosensor were optimized by using an DPV method. The linear range of biosensor for the detection of H2O2 was 5.0×10^-6 mol/L to 1. 0×10^-3 mol/L and a detective limit of 2. 5 μmoL/L. The equation was △I = 0. 34765 ＋4. 05553 CH202 （ mM ）. The apparent Michaelis-Menten constant （ Km ^app ） for the sensor was determination to be 0. 0675 mmol/L. The characteristics of our sensor include well-retained enzyme activity, long lifetime and high stability for the detection of H2O2.