黄芩素在聚-L-赖氨酸修饰电极上的电化学研究

<研究了黄芩素(baicalein, 缩写BAI)在玻碳电极(GCE)与聚-L-赖氨酸修饰的玻碳电极(PLL/GCE)上的电化学行为. 发现BAI不能在裸玻碳电极上产生明显的氧化还原信号, 但在PLL/GCE上有一对可逆性较好的氧化还原峰出现. 在最佳实验条件下, 氧化峰电流与BAI的浓度在5.0×10－7～1.0×10－5 mol/L范围内呈良好的线性关系, 相关系数R为0.998, BAI检测限为4.8×10－8 mol/L(信号与噪声比S/N＝3). 配10份相同浓度溶液, 每次测定后需重新修饰电极, 连续测定10次, 所得结果的相对标准偏差(RSD)为4.3%, 平均峰电流为1.48 μA. 这表明修饰电极具有良好的重现性. 将该方法用于BAI在尿样中的回收率分析, 结果令人满意.

Electrochemical Study on Baicalein at Poly-L-lysine Modified Glass Carbon Electrode

The electrochemical behavior of baicalein (BAI) was investigated at a glass carbon electrode (GCE) and a poly-L-lysine modified glass carbon electrode (PLL/GCE). The result showed that a pair of reversible redox peaks that did not emerge at GCE was observed at PLL/GCE, which indicated that PLL/GCE performed effective electrochemical response to BAI. Under optimal conditions, a good linear relationship between the anodic peak current and concentration was obtained in the range of 5.0×10~(-7)～1.0× 10~(-5) mol/L with the detection limit of 4.8 × 10~(-8) mol/L (S/N=3). The responses of repeated measurements at the renewed surface of the PLL/GCE were examined with relative standard deviation of 4.3% (n=10), respectively, indicating that the chemically modified electrode showed excellent reproducibility. The proposed method has been used to determine baicalein concentration in urine samples with satisfactory results.