Institute of Cytology and Genetics, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
Institute for Future Sciences, University of South China, Changsha, Hunan 410000, China.
Anal Methods. 2024 May 9;16(18):2905-2912. doi: 10.1039/d4ay00322e.
The presence of lead ions (Pb) in the environment not only leads to environmental contamination but also poses a significant risk to public health through their migration into food and drinking water. Therefore, the development of rapid and effective techniques for detection of trace amounts of Pb is crucial for safeguarding both the environment and biosafety. In this study, an aptamer-based electrochemical sensor was developed for specific detection of Pb by modifying a polylysine (PLL) coated silver-thiolated graphene (Ag-SH-G) nanocomposite (PLL/Ag-SH-G) on the surface of a glassy carbon electrode, which was further modified with gold nanoparticles (AuNPs) for attachment of aptamers (Apt) that specifically recognized Pb. The Ag-SH-G particles were synthesized using a one-step method, resulting in significantly enhanced electrochemical properties upon incorporating Ag nanoparticles into the PLL/Ag-SH-G composite. Coating of the covalently or no-covalently bonded Ag-SH-G particles with PLL provides an excellent supporting matrix, facilitating the assembly of AuNPs and a thiol-modified aptamer for Pb. Under optimized conditions, Apt/AuNPs/PLL/Ag-SH-G/GCE exhibited excellent sensing performance for Pb with a wide linear response range (10-1000 nM), a low detection limit (0.047 nM) and extraordinary selectivity. The sensor was employed and satisfactory results were obtained in river water, soil and vegetable samples for the detection of Pb.
环境中铅离子（Pb）的存在不仅导致环境污染，而且通过迁移到食物和饮用水中对公众健康构成重大威胁。因此，开发快速有效的痕量 Pb 检测技术对于保障环境和生物安全至关重要。在这项研究中，通过在玻碳电极表面修饰聚赖氨酸（PLL）包覆的银硫代石墨烯（Ag-SH-G）纳米复合材料（PLL/Ag-SH-G），进一步修饰金纳米粒子（AuNPs）以附着特异性识别 Pb 的适配体（Apt），开发了一种基于适配体的电化学传感器，用于特异性检测 Pb。Ag-SH-G 颗粒通过一步法合成，在 PLL/Ag-SH-G 复合材料中掺入 Ag 纳米粒子后，电化学性能得到显著增强。用 PLL 共价或非共价键合的 Ag-SH-G 颗粒涂覆提供了极好的支撑基质，有利于 AuNPs 和巯基修饰的适配体组装用于 Pb。在优化条件下，Apt/AuNPs/PLL/Ag-SH-G/GCE 对 Pb 表现出优异的传感性能，具有较宽的线性响应范围（10-1000 nM）、较低的检测限（0.047 nM）和非凡的选择性。该传感器用于河水、土壤和蔬菜样品中 Pb 的检测，结果令人满意。
