Chen Jiayu, Ji Chun, Wang Xiao, Tian Yunxia, Tao Han
School of Liquor and Food Engineering, Guizhou Province Key Laboratory of Fermentation Engineering and Biopharmacy, Guizhou University Huaxi District Guiyang 550025 China
School of Pharmaceutical Sciences, Guizhou University Huaxi District Guiyang 550025 China.
RSC Adv. 2024 Apr 2;14(15):10703-10713. doi: 10.1039/d4ra00009a. eCollection 2024 Mar 26.
Chlorpyrifos (CPF) is the most common pesticide entering the food chain and posing a threat to human health. This study presents a new electrochemical biosensor based on molybdenum disulfide nanosheets and nitrogen-doped carbon dot nanocomposite (MoS@N-CDs) and kidney bean esterase (KdBE), and it is shown to achieve accurate detection of CPF. MoS@N-CDs were prepared by a facile solvothermal method and characterized by electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Electrochemical characterization confirmed that MoS@N-CDs facilitated electron transfer and increased the electroactive surface area of the electrode, thereby improved the sensing performance of the electrode. The oxidation peak current of 1-naphthol, which was produced by the hydrolysis of 1-naphthyl acetate catalyzed by KdBE, was adopted as the signal of the sensor. CPF can suppress KdBE activity and consequently cause a decrease in the sensing signal. The experimental results show that the variation of sensing signal is a reliable index to evaluate the CPF level. Under the optimized conditions, the developed enzyme sensor showed superior CPF assay performance with a linear detection range as wide as 0.01-500 μg L and LOD as low as 3.5 × 10 μg L (S/N = 3). The inter- and intra-batch RSDs for electrode testing were 4.02% and 2.69%, respectively. Moreover, the developed biosensor also showed good stability and anti-interference. The spiked recoveries of CPF in oilseed rape and cabbage ranged from 98.09% to 106.01% with low relative standard deviation (RSD) (<5.23%), suggesting that the sensor is a promising tool to enable simple, low-cost but highly sensitive large-scale screening of CPF residues in food.
毒死蜱（CPF）是进入食物链并对人类健康构成威胁的最常见农药。本研究提出了一种基于二硫化钼纳米片和氮掺杂碳点纳米复合材料（MoS@N-CDs）以及菜豆酯酶（KdBE）的新型电化学生物传感器，该传感器被证明能实现对CPF的准确检测。MoS@N-CDs通过简便的溶剂热法制备，并通过电子显微镜、X射线衍射和X射线光电子能谱进行表征。电化学表征证实，MoS@N-CDs促进了电子转移并增加了电极的电活性表面积，从而提高了电极的传感性能。以KdBE催化乙酸萘酯水解产生的1-萘酚的氧化峰电流作为传感器的信号。CPF可抑制KdBE活性，从而导致传感信号降低。实验结果表明，传感信号的变化是评估CPF水平的可靠指标。在优化条件下，所开发的酶传感器表现出优异的CPF检测性能，线性检测范围宽达0.01 - 500 μg L，检测限低至3.5×10 μg L（S/N = 3）。电极测试的批间和批内相对标准偏差（RSD）分别为4.02%和2.69%。此外，所开发的生物传感器还表现出良好的稳定性和抗干扰性。油菜和卷心菜中毒死蜱的加标回收率在98.09%至106.01%之间，相对标准偏差较低（RSD）（<5.23%），这表明该传感器是一种有前景的工具，可用于简单、低成本但高灵敏度地大规模筛查食品中的毒死蜱残留。
