壳聚糖复合碳纳米管修饰超薄碳糊电极对硝基酚异构体的同时测定

Simultaneous Determination of Nitrophenol Isomers Using Ultra-thin Carbon Paste Electrode Modified with Chitosan Carbon Nanotubes Composite

以镍镉合金为基底,将壳聚糖滴涂在碳纳米管修饰的超薄碳糊电极表面制成电化学传感器（CTSCNTs-UTCPE）,利用循环伏安法（CV）、半微分伏安法研究硝基酚异构体在该电极上的电化学行为。考察了底液种类、酸碱度、扫描速度、起始电位和富集时间对检测结果的影响。与镍铬合金电极、超薄碳糊电极（UTCPE）和碳纳米管修饰超薄碳糊电极（CNTs-UTCPE）相比,由于壳聚糖和碳纳米管的协同效应,硝基酚异构体在p H 5.72的B-R中氧化电流较高。在最佳条件下,传感器对邻、间、对硝基酚的检测范围分别为4.0×10-7-8.0×10-5mol/L,4.0×10-7-8.0×10-5mol/L,8.0×10-7-8.0×10-5mol/L;检出限（S/N=3）分别为2.3×10-7,2.9×10-7,6.7×10-7mol/L。该传感器显示出良好的稳定性和抗干扰性能,可实现对人工水样中硝基酚异构体的同时检测。

Based on nickel chromium substrate, a novel electochemical sensor was prepared by coat- ing chitosan on the surface of nanotubes modified ultra thin carbon paste electrode （ CTS - CNTs - UTCPE）, and this sensor was further employed for electrochemical determination of o-, m- and p-ni- trophenol. Electrochemical behaviors of o-, m- and p-nitrophenol on CTS -CNTs- UTCPE were in- vestigated by cyclic vohammetry（CV） and semi-differential vohammetry method. Effects of supporting electrolyte, pH value, onset potential, scan rate and accumulation time on the result of detection were explored. Compared to nickel chromium electrode, ultra thin carbon paste electrode （UTCPE） and carbon nanotubes modified ultra thin carbon paste electrode （ CNTs - UTCPE）, the new electrode displays a larger oxidative current response to o-, m- and p-nitrophenol in pH 5.72 B - R solution, probably due to the synergistic effects between chitosan and carbon nanotubes. Under the optimum conditions, the presented sensor exhibited wide linear responses to o-nitrophenol ranging from 4. 0 x 10 -Tmol/L to 8.0× 10 -5 mol/L with a detection limit（S/N = 3） down to 2. 3× 10 -7 mol/L, to m-ni- trophenol ranging from 4. 0 ×10 -7 mol/L to 8.0× 10 -5 mol/L, with a detection limit down to 2.9 × 10 -7 mol/L, to p-nitrophenol ranging from 8.0× 10 -7 to 8.0× l0 -5 mol/L with a detection limit down to 6. 7 x 10-7 mol/L. This presented sensor also showed a good stability and an excellent se- lectivity, and was successfully applied in the simultaneous determination of o-, m- and p-nitrophenol in artificial water samples.