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用循环伏安法研究了2-巯基嘧啶(MP)、4-氨基-2-巯基嘧啶(AMP)及4,6-二氨基-2-巯基嘧啶(DAMP)自组装修饰金电极的制备及其对细胞色素c直接电子传递的促进作用。用扫描电子显微镜(SEM)表征了2-巯基嘧啶衍生物修饰金电极的表面形貌。细胞色素c在MP、AMP修饰金电极上能进行准可逆的电化学反应,氧化还原峰电位差(ΔEp)分别为61 mV和86 mV,氧化与还原峰电流比ipa/ipc接近1,峰电流与电位扫描速率平方根(v1/2)呈正比,是扩散控制的准可逆过程,异相电子迁移速率常数(Ks)分别为1.4×10-3cm·s-1和5.1×10-5cm·s-1。金电极在2.0 mmol·L-1MP、AMP溶液中分别浸泡3 h和9 h,促进效果较好。随2-巯基嘧啶环上取代氨基数的增加,对细胞色素c电化学反应的促进作用及电极的稳定性逐渐减弱,即MP>AMP,而DAMP基本无促进作用。
The preparation of 2-mercaptopyrimidine (MP), 4-amino-2-mercaptopyrimidine (AMP) and 4,6-diamino-2-mercaptopyrimidine (DAMP) modified gold electrode by cyclic voltammetry Promotes the direct electron transfer of cytochrome c. The surface morphology of 2-mercaptopyrimidine derivative modified gold electrode was characterized by scanning electron microscopy (SEM). Quasi-reversible electrochemical reaction of cytochrome c on MP and AMP modified gold electrodes was achieved with 61 mV and 86 mV redox potential difference (ΔEp), respectively. The peak current-to-current ratio (ipa / ipc) Which is proportional to the square root of potential sweep rate (v1 / 2), is a quasi-reversible process for diffusion control. The heterogeneous electron mobility constant (Ks) are 1.4 × 10-3cm · s-1 and 5.1 × 10-5cm · s- 1. The gold electrode immersed in 2.0 mmol·L-1MP, AMP solution for 3 h and 9 h, respectively, which promoted the effect better. With the increase of the number of substituted amino groups on 2-mercaptopyrimidine ring, the effect on the electrochemical reaction of cytochrome c and the stability of the electrode gradually diminished, ie, MP> AMP, while DAMP had no effect.