Nie Yonghui, Teng Yuanjie, Li Pan, Liu Wenhan, Shi Qianwei, Zhang Yuchao
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Feb 15;191:271-276. doi: 10.1016/j.saa.2017.10.030. Epub 2017 Oct 10.
A novel label-free aptamer surface-enhanced Raman scattering (SERS) sensor for trace malathion residue detection was proposed. In this process, the binding of malathion molecule with aptamer is identified directly. The silver nanoparticles modified with positively charged spermine served as enhancing and capture reagents for the negatively charged aptamer. Then, the silver nanoparticles modified by aptamer were used to specifically capture the malathion. The SERS background spectra of spermine, aptamer, and malathion were recorded and distinguished with the spectrum of malathion-aptamer. To enhance the characteristic peak signal of malathion captured by the aptamer, the aggregate reagents (NaCl, KCl, MgCl) were compared and selected. The selectivity of this method was verified in the mixed-pesticide standard solution, which included malathion, phosmet, chlorpyrifos-methyl, and fethion. Results show that malathion can be specifically identified when the mixed-pesticide interferences existed. The standard curve was established, presenting a good linear range of 5×10 to 1×10mol·L. The spiked experiments for tap water show good recoveries from 87.4% to 110.5% with a relative standard deviation of less than 4.22%. Therefore, the proposed label-free aptamer SERS sensor is convenient, specifically detects trace malathion residues, and can be applied for qualitative and quantitative analysis of other pesticides.
提出了一种用于痕量马拉硫磷残留检测的新型无标记适体表面增强拉曼散射（SERS）传感器。在此过程中，直接识别马拉硫磷分子与适体的结合。用带正电荷的精胺修饰的银纳米颗粒用作带负电荷适体的增强和捕获试剂。然后，用适体修饰的银纳米颗粒特异性捕获马拉硫磷。记录了精胺、适体和马拉硫磷的SERS背景光谱，并与马拉硫磷-适体光谱进行了区分。为增强适体捕获的马拉硫磷的特征峰信号，对聚集试剂（氯化钠、氯化钾、氯化镁）进行了比较和选择。在包括马拉硫磷、亚胺硫磷、甲基毒死蜱和倍硫磷的混合农药标准溶液中验证了该方法的选择性。结果表明，在存在混合农药干扰的情况下，仍能特异性识别马拉硫磷。建立了标准曲线，呈现出5×10至1×10mol·L的良好线性范围。自来水加标实验显示回收率良好，为87.4%至110.5%，相对标准偏差小于4.22%。因此，所提出的无标记适体SERS传感器操作简便，能特异性检测痕量马拉硫磷残留，可用于其他农药的定性和定量分析。
