电聚合烟酰胺制备电化学传感器：同时测定多巴胺、尿酸和抗坏血酸

用循环伏安法（CV）选择不同电位区间来电聚合烟酰胺（NA）得到了两种聚合物膜修饰电极：poly-niacinamide/GCE (poly-NA/GCE)和poly- nicotinic acid /GCE (poly-NC/GCE)。这两电极都具有显著电化学催化作用，能明显地降低多巴胺（DA）、尿酸（UA）和抗坏血酸(AA)的氧化过电位，并在混合溶液中使这些物质的氧化峰电位距离足够大，可进行三物质的同时测定。poly-NC/GCE的电催化性能更好一些，用差分脉冲伏安法（DPV）测定抗坏血酸，线性范围为75–3000 µmol L-1，电流灵敏度为5.6 mA•L•mol-1；测定多巴胺，线性范围为0.37 – 16 µmol L-1，电流灵敏度为1140 mA•L•mol-1； 测定尿酸，线性范围为0.74 – 230 µmol L-1，电流灵敏度为102 mA•L•mol-1。该电极具有很高的灵敏度、选择性和抗污染能力。

Eletropolymerization of Niacinamide for Fabrication of Electrochemical Sensor: Simultaneous Determination of Dopamine,Uric Acid and Ascorbic Acid

Two polymeric thin film modified electrodes, poly‐niacinamide/glassy carbon electrode (poly‐NA/GCE) and poly‐nicotinic acid/glassy carbon electrode (poly‐NC/GCE), have be fabricated at glassy carbon electrodes by simple electropolymerization of niacinamide (NA) in different potential scan ranges of cyclic voltammetry (CV). These two electrodes all showed catalytic ability towards the oxidation of dopamine (DA), uric acid (UA) and ascorbic acid (AA) by obvious reductions of overpotentials, giving well‐resolved voltammetric peaks, which allow simultaneously determination of DA, UA and AA. The poly‐NC/GCE showed even higher electrocatalytic activity than the poly‐NA/GCE. The electrochemical behavior of poly‐NC/GCE was investigated by CV and differential pulse voltammetry (DPV) for determination of DA, UA and AA. The linear ranges of the concentration for the determination of AA, DA and UA using DPV were 75–3000, 0.37–16 and 0.741–230 mol·L^?1, respectively. The slopes of the linear calibration curves for the detection were estimated to be 5.6, 1140 and 102 mA·L·mol^?1 for AA, DA and UA, respectively. The poly‐NC/GCE shows excellent sensitivity, good selectivity and antifouling properties.