College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002, P. R. China.
Anal Chem. 2011 Jul 1;83(13):5290-5. doi: 10.1021/ac200706k. Epub 2011 Jun 3.
A novel photoelectrochemical sensor for detection of the organophosphorus pesticide (OP) dichlofenthion using nanometer-sized titania coupled with a screen-printed electrode is presented. Nonelectroactive dichlofenthion can be indirectly determined through the photocatalytical degradation of dichlofenthion with nanometer-sized titania. The electrochemical characterization and anodic stripping voltammetric performance of dichlofenthion were evaluated using cyclic voltammetric (CV) and differential pulse anode stripping voltammetric (DPASV) analysis, respectively. DPASV analysis was used to monitor the amount of dichlofenthion and provide a simple, fast, and facile quantitative method for dichlofenthion. Operational parameters, including the photocatalysis time, pH of buffer solution, deposition potential, and accumulation time have been optimized. The stripping voltammetric response is linear over the 0.02-0.1 and 0.2-1.0 μmol/L ranges with a detection limit of 2.0 nmol/L. The assay result of dichlofenthion in green vegetable with the proposed method was in acceptable agreement with that of the gas chromatograph-mass spectrometer (GC-MS) method. The promising sensor opens a new opportunity for fast, portable, and sensitive analysis of OPs in environmental samples.
一种使用纳米二氧化钛结合丝网印刷电极检测有机磷农药（OP）二氯噻丰的光电化学传感器。非电化学活性的二氯噻丰可以通过纳米二氧化钛的光催化降解来间接测定。采用循环伏安法（CV）和差分脉冲阳极溶出伏安法（DPASV）分别对二氯噻丰的电化学特性和阳极溶出伏安性能进行了评价。DPASV 分析用于监测二氯噻丰的含量，并提供了一种简单、快速、方便的二氯噻丰定量方法。优化了包括光催化时间、缓冲溶液 pH 值、沉积电位和积累时间在内的操作参数。在 0.02-0.1 和 0.2-1.0 μmol/L 范围内，溶出伏安响应呈线性，检出限为 2.0 nmol/L。该方法对蔬菜中二氯噻丰的检测结果与气相色谱-质谱（GC-MS）法基本一致。这种有前景的传感器为快速、便携和灵敏地分析环境样品中的 OP 开辟了新的机会。
