基于Fe_3O_4/Au磁性复合纳米材料胆固醇生物传感器的研究

Highly-sensitive Cholesterol Biosensor Based on Au/Fe_3O_4 Nanocomposite

用两步法合成Fe3O4/Au磁性复合纳米材料,并通过修饰于金电极表面的L-半胱氨酸的巯基吸附Fe3O4/Au纳米复合材料,再利用静电吸附固载胆固醇氧化酶（ChOx）,构建了高灵敏、稳定的新型电流型胆固醇生物传感器.实验表明,该生物传感器对胆固醇检测范围宽（1.4＆#215;10-6～3.85＆#215;10-3 mol＆#183;L-1）,检出限低（4.6＆#215;10-7mol＆#183;L-1）,灵敏度高（264 μA/mol＆#183;L-1）.

Fe3O4/Au magnetic composite nanomaterials were synthesized via a two-step process and then were immobilized onto the surface of L-cysteine modified gold electrodes owing to the adsorption of Fe304/Au nanocomposites by L-cysteine. After that, cholesterol oxidase （ChOx） was immobilized on Fe3O4/Au nanocomposites via electrostatic adsorption in order to obtain get cholesterol modified electrode. The proposed cholesterol modified electrode can be used as a novel sensitive and stable current biosensor for cholesterol in the linear range of 1.4×10-6 -3.85×10-3 mol·L-1, with the limit of detection of 4.6×10-7 mol·L-1 and the sensitivity of 264μA·L-mol-1.