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利用单壁纳米碳管(SWNT)优异的电学性能和催化特性以及DNA特定的分子识别功能,成功构建了一种高灵敏度、快速测定双酚A(BPA)的电化学传感器。在pH7.0的磷酸缓冲溶液中,BPA在SWNT-DNA复合修饰电极上的氧化电流信号是空白电极上的10倍。在10～200 mV/s扫速范围内,氧化峰电流与扫速呈线性关系,表明该氧化过程受吸附控制,通过理论计算,BPA在修饰电极上的反应是一个双电子和双质子过程。在最优的实验条件下,采用差分脉冲伏安法(DPV)对BPA进行测定,氧化电流与BPA浓度在1.0×10-8～2.0×10-5mol/L范围内呈良好的线性关系(r=0.9954),检出限为5.0×10-9mol/L(S/N=3)。该方法初步用于实际样品分析,BPA的加标回收率为93.1%～109.3%。
An electrochemical sensor with high sensitivity and rapid determination of bisphenol A (BPA) was constructed successfully using the excellent electrical and catalytic properties of single-walled carbon nanotubes (SWNTs) and DNA-specific molecular recognition. The oxidation current signal of BPA on SWNT-DNA composite modified electrode was 10 times higher than that of blank electrode in pH7.0 phosphate buffer solution. In the range of 10 ~ 200 mV / s, there is a linear relationship between the oxidation peak current and the sweeping velocity, indicating that the oxidation process is controlled by adsorption. The theoretical calculation shows that the reaction of BPA on the modified electrode is a two-electron and two-proton process. Under the optimal experimental conditions, the differential pulse voltammetry (DPV) was used to determine BPA. The oxidation current showed a good linear relationship with the concentration of BPA in the range of 1.0 × 10-8 ~ 2.0 × 10-5mol / L (r = 0.9954), the detection limit was 5.0 × 10-9mol / L (S / N = 3). The method was initially applied to the actual sample analysis. The spiked recoveries of BPA ranged from 93.1% to 109.3%.