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超氧自由基(O2·-)检测对于研究氧化损伤有关的生化及病理过程具有重要意义.本文基于金纳米棒/超氧化物歧化酶层层自组装方法构建了一种新型超氧自由基电化学传感器.通过带正电的十六烷基三甲基溴化铵(CTAB)包裹的金纳米棒(AuNRs)与带负电的超氧化物歧化酶(SOD)在半胱氨酸(Cys)修饰的金(Au)电极上层层自组装制备了(SOD/AuNRs)2/Cys/Au电极,证明了金纳米棒/SOD双层组装膜能有效增强SOD与电极之间的电子转移,并且该电极中的SOD保持有良好的生物活性,可在还原电位下实现O2·-电催化还原,从而达到检测O2·-的目的.该超氧自由基电化学传感器表现出了良好的电分析性能,其检测线性范围为200nM～0.2mM,检测限为100nM(S/N=3),灵敏度为22.11nAcm-2μM-1,响应时间为5s.此外,该传感器还显示了较好的稳定性以及排除常见共存物过氧化氢、尿酸和抗坏血酸等干扰的能力.因此,对于第三代超氧化物歧化酶传感器的制作来说,酶与纳米材料层层自组装方法能够提供一种有效的电极构建方式.
Detection of superoxide radical (O2 · -) is of great significance to study the biochemical and pathological processes involved in oxidative damage.In this paper, a new type of superoxide radical based on self-assembly of gold nanorods / superoxide dismutase Chemical sensors - Gold nanorods (AuNRs) wrapped with positively charged cetyltrimethylammonium bromide (CTAB) and cysteine (Cys) modified with negatively charged superoxide dismutase (SOD) (SOD / AuNRs) 2 / Cys / Au electrodes were prepared by self-assembly of Au (Au) electrodes. It is demonstrated that the gold nanorods / SOD dual-layer assembled films can effectively enhance the electron transfer between SOD and the electrodes, SOD has good biological activity and can achieve O2 · electrocatalytic reduction under reduction potential to achieve the purpose of detecting O2 · .The superoxide radical electrochemical sensor shows good electro- The detection limit ranged from 200nM to 0.2mM, the detection limit was 100nM (S / N = 3), the sensitivity was 22.11nAcm-2μM-1 and the response time was 5s. In addition, the sensor also showed good stability and exclusion of common Coexistence of hydrogen peroxide, uric acid and ascorbate, etc. Therefore, for the third Production of superoxide dismutase sensor, the enzyme and the nanomaterial layer self-assembly method can provide an effective way to build electrode.