Semiconductor Nanocrystals-Reduced Graphene Composites for the Electrochemical Detection of Carbendazim

A new nanocomposite based on ZnCdTe semiconductor nanocrystals (NCs) synthesized in situ on reduced graphene oxide (rGO) was obtained. The heterostructure was characterized using UV-Vis emission and absorption spectroscopies, which provided evidences of the growth of the nanocrystals onto the rGO matrix. To evaluate the electrochemical performance, carbon paste electrodes modified with the nanocomposite (QD-rGO/CPE) were prepared, showing high sensitivity in the electroanalytical detection of the pesticide carbendazim. Under optimal operational conditions a calibration curve was constructed with a linear behavior in the range of 9.98 × 10-8 to 1.18 × 10-5 mol L-1, with a correlation coefficient of 0.997. The limit of detection (LOD) and the limit of quantification (LOQ) for carbendazim were 9.16 × 10-8 and 2.78 × 10-7 mol L-1, respectively. The electrode is successfully applied for the determination of carbendazim in orange juice samples.

本研究成功制备了一种以ZnCdTe半导体纳米晶（semiconductor nanocrystals, NCs）为基础的新型纳米复合材料，该纳米晶原位合成于还原氧化石墨烯（reduced graphene oxide, rGO）表面。通过紫外-可见发射与吸收光谱对该异质结构进行表征，结果证实了纳米晶在还原氧化石墨烯基底上的生长。为评估该复合材料的电化学性能，本研究制备了经该纳米复合材料修饰的碳糊电极（QD-rGO/CPE），其在农药多菌灵的电分析检测中展现出优异的灵敏度。在最优操作条件下构建的校准曲线呈现良好线性关系，线性范围为9.98×10^-8 至 1.18×10^-5 mol·L^-1，相关系数达0.997。多菌灵的检出限（LOD）与定量限（LOQ）分别为9.16×10^-8 mol·L^-1和2.78×10^-7 mol·L^-1。该修饰电极已成功应用于橙汁样品中多菌灵的含量测定。