Dai Shuxian, Hu Mengting, Zhang Wen, Lei Zhen
School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan, 430205, China.
School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan, 430205, China.
Anal Chim Acta. 2025 Jan 22;1336:343519. doi: 10.1016/j.aca.2024.343519. Epub 2024 Dec 3.
Carbosulfan (CBS) is a widely used carbamate pesticide in agricultural production, its easy decomposition into hypertoxic carbofuran poses serious threats to human health and food safety. Therefore, sensitive and accurate detection of CBS is of significant importance. Conventional chromatography-based techniques require expensive instruments and complicated sample pretreatment, limiting their application for fast detection. Current electrochemical and colorimetric methods for detection of pesticides based on the cascade catalytic reactions between acetylcholinesterase (AChE) and nanozymes, which exhibit inferior selectivity. Hence, selective, sensitive and fast detection of CBS is still challenging.
In this work, an AChE-free colorimetric method was proposed for selective detection of CBS based on its unique hydrolysis behavior and nanozyme. TiC nanosheets/AuPt nanoparticles (TiC/AuPt NPs) with enhanced peroxidase-like activity were prepared via one-step self-reduction reaction. CBS can be hydrolyzed under acidic condition and produce -SH moieties, which could bond to Pt atoms of TiC/AuPt NPs and shield the active sites of nanozyme, resulting in decreased catalytic activity. Based on the inhibitory effect on the peroxidase-like activity of TiC/AuPt NPs, a colorimetric method was proposed for direct detection of CBS. Under optimal conditions, the method showed wide linear range (0.5 ng mL-5 μg mL), low limit of detection (0.342 nM), good selectivity and anti-interference ability. The feasibility of this method for practical use was confirmed by analysis of CBS in real lake water samples.
This work proposed a simple colorimetric method for selective and fast detection of CBS, which avoided employing AChE and cascade catalytic reactions, significantly lowering the detection cost and improving detection efficiency. The method showed great potential for accurate detection of CBS in actual samples, and provided a new avenue for developing nanozyme-based colorimetric method for detection of other pesticide residues.
丁硫克百威（CBS）是农业生产中广泛使用的氨基甲酸酯类农药，其易分解为高毒性的克百威，对人类健康和食品安全构成严重威胁。因此，灵敏准确地检测CBS具有重要意义。传统的基于色谱的技术需要昂贵的仪器和复杂的样品预处理，限制了它们在快速检测中的应用。目前基于乙酰胆碱酯酶（AChE）与纳米酶之间的级联催化反应检测农药的电化学和比色法，选择性较差。因此，选择性、灵敏且快速地检测CBS仍然具有挑战性。
在这项工作中，基于CBS独特的水解行为和纳米酶，提出了一种无需AChE的比色法用于选择性检测CBS。通过一步自还原反应制备了具有增强类过氧化物酶活性的TiC纳米片/AuPt纳米颗粒（TiC/AuPt NPs）。CBS在酸性条件下可水解并产生-SH基团，该基团可与TiC/AuPt NPs的Pt原子结合并屏蔽纳米酶的活性位点，导致催化活性降低。基于对TiC/AuPt NPs类过氧化物酶活性的抑制作用，提出了一种直接检测CBS的比色法。在最佳条件下，该方法具有宽线性范围（0.5 ng mL-5 μg mL）、低检测限（0.342 nM）、良好的选择性和抗干扰能力。通过对实际湖水样品中CBS的分析，证实了该方法实际应用的可行性。
这项工作提出了一种简单的比色法用于选择性和快速检测CBS，避免了使用AChE和级联催化反应，显著降低了检测成本并提高了检测效率。该方法在实际样品中准确检测CBS方面显示出巨大潜力，并为开发基于纳米酶的比色法检测其他农药残留提供了新途径。
