Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Institute of Applied Chemistry, Guizhou University, Guiyang, 550025, China.
Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Institute of Applied Chemistry, Guizhou University, Guiyang, 550025, China.
Anal Chim Acta. 2022 Aug 15;1221:340148. doi: 10.1016/j.aca.2022.340148. Epub 2022 Jul 11.
Aptamers are single-stranded DNA or RNA that can specifically bind to a target substance with high affinity. Pesticides have obvious biological effects and are very harmful to the human body and the environment. Surface-enhanced Raman spectroscopy (SERS) can be combined with aptamer for the rapid detection of pesticide residues because of its simple operation and high sensitivity. However, a single analysis method has certain limitations and can't satisfy the research of complex system. In this study, SERS and electrochemical were used to prove the specific recognition of malathion by aptamer. The biochemical sensor directly detected the SERS spectra of the aptamer, malathion, and aptamer-malathion through the SERS method. Malathion could also be verified the specific recognition of aptamer by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Based on the peak difference before and after the combination of malathion and aptamer, a detection method for the specific recognition of malathion in a complex system was established. The identification mechanism was discussed. Then, the practical detection of malathion demonstrated the practicability of the method. The method was applied for the detection of malathion in spiked apple and bell pepper samples. The recoveries were in the range of 89.80%-106.50%, and the relative standard deviations were from 2.51%-6.92%. The use of aptamers for the specific detection of pesticides will have the potential for broad applications in the future.
适配体是一种单链 DNA 或 RNA，能够与目标物质特异性结合，具有高亲和力。农药具有明显的生物效应，对人体和环境非常有害。表面增强拉曼光谱（SERS）可以与适配体结合，用于快速检测农药残留，因为它具有操作简单、灵敏度高的特点。然而，单一的分析方法存在一定的局限性，不能满足复杂体系的研究需要。本研究利用 SERS 和电化学方法证明了适配体对马拉硫磷的特异性识别。该生化传感器通过 SERS 方法直接检测适配体、马拉硫磷和适配体-马拉硫磷的 SERS 光谱。差分脉冲伏安法（DPV）和循环伏安法（CV）也可以验证马拉硫磷对适配体的特异性识别。基于马拉硫磷与适配体结合前后的峰差，建立了用于复杂体系中马拉硫磷特异性识别的检测方法，并对其识别机制进行了探讨。然后，对实际样品中马拉硫磷的检测验证了该方法的实用性。该方法应用于加标苹果和甜椒样品中马拉硫磷的检测，回收率在 89.80%-106.50%之间，相对标准偏差在 2.51%-6.92%之间。利用适配体特异性检测农药将具有广阔的应用前景。
