基于金纳米-植酸胶束混合组装的过氧化氢传感器的电化学研究

采用混合组装技术,利用植酸胶束(IP6micelles)的磷酸酯键络合辣根过氧化物酶(HRP)和金纳米粒子(GNPs),形成了具有生物亲和性的纳米复合材料,保持了辣根过氧化物酶的生物活性,并利用金纳米粒子的高电子密度、介电特性和催化性能,实现了HRP与玻碳电极(GCE)表面的直接电子转移。Nafion膜的滴加能提高电极的选择性和稳定性。实验过程中借助紫外-可见吸收光谱和透射电子显微镜进行表征,实验结果证明:GNPs的高导电和高催化性能,结合植酸胶束的优良生物相容性和对酶的高负载量的特点,使得吸附在其上的HRP保持活性,制备的生物传感器能对H2O2进行电催化还原。Nafion/HRP-IP6micelles-GNPs/GCE对H2O2的线性浓度范围为5×10-7～1.15×10-5mol/L(线性相关系数r=0.993,n=9),最低检测限为0.1μmol/L(信噪比S/N=3),米氏常数为0.002 4 mmol/L。

Hydrogen peroxide biosensor based on gold nanoparticles-phytic acid micelle mixed assemble

A hybrid and bio-compatible sensor constructed with IP6 micelles phosphate bonded horseradish peroxidase and gold nanoparticles. The nano-composite materials not only keep the biological activity of horseradish peroxidase, but also achieve the high electron density, dielectric properties and catalytic performance of gold nanoparticles to facilitate the direct electron transfer. Furthermore, Nation membrane can improve the selectivity and stability of sensor. The characterizations of UV-visible absorption spectroscopy and transmission electron microscopy showed that the high conductivity and high catalytic properties of nanoparticles together with the excellent biocompatibility and high enzyme loading IP6 micelles made the adsorption of HRP and maintained its activity. Nafion/HRP-IP6 micelles-GNPs/GCE biosensor can electrocatalytically reduce H2O2. The current response with the concentration of H202 has a linear relationship within the concentration range of 5×10^-7～1.15×10^-5mol/L （linear correlation coefficient r = 0.993, n = 9）, the detection limit was 0.1μmol/L （signal to noise ratio S/N = 3）, Michaelis constant of 0.002 4 mmol/L.