聚中性红膜修饰碳糊电极的电化学研究及其对维生素K3的检测

Electrochemical Study of Poly Neutral Red Film Modified Carbon Paste Electrode for the Determination of Vitamin K3

在一定温度下,以K2S2O8作引发剂,分别采用化学引发-电聚合和电引发-电聚合的方法制备了聚中性红膜修饰碳糊电极（PNR/CPE）。运用循环伏安法（CV）对修饰电极进行表征,并通过扫描电子显微镜（SEM）对聚合膜的表面形貌进行观察分析,推断了成膜的可能机理,探讨了最佳聚合条件。研究了维生素K3在该修饰电极上的电化学行为,并用差分脉冲伏安法（DPV）对其含量进行了测定。研究结果表明：经过化学引发后,中性红单体自由基增多,提高了成膜效率,此电极在NH3-NH4Cl溶液中对维生素K3有更好的电催化作用,其还原峰电流与浓度在2.0×10-6~1.2×10-4 mol/L范围内呈现出良好的线性关系,检出限为2.0×10-7 mol/L,回收率为94.7%~108.0%。

By using K2S2O8 as initiator to react with neutral red in a phosphate buffer solution at a certain temperature,apoly neutral red modified carbon paste electrode（PNR/CPE）was fabricated by the electrochemical polymerization of neutral red on carbon paste electrode（CPE）.Meanwhile,another modified electrode was fabricated by the method of electrochemical initation.The modified electrodes were characterized by cyclic voltammetry（CV）and the structural morphology of the polymerized film was observed by SEM.The film-forming mechanism was deduced and the optimal polymerization conditions were studied.The electrochemical behaviors of VK3 on the modified electrodes were studied by CV,and the differential pulse voltammetry（DPV）was used to detect the content of VK3 in the sample.The results indicated that the free radical of neutral red monomer increased after chemical initiation,improving the efficiency of film-forming.The PNR/CPE（chemical initiation）showed a strong electrocatalytic ability for VK3 in NH3-NH4 Cl buffer.The reduction peak currents and concentrations of VK3 had a good linear relationship in the range from 2.0×10-7 mol/L to 1.2×10-4 mol/L with a detection limit of 2.0×10-8 mol/L and the recoveries of 94.7%-108.0%.