As the concentrations of different neurotransmitters can indicate the presence of certain disorders affecting brain functions, quantitative analyses of neurotransmitters have attracted increasing attention in various fields. Surface-enhanced Raman scattering (SERS) spectroscopy is an outstanding spectroscopic analytical tool that enables detection at the single molecule level with high specificity. As local field enhancement of surface plasmon is effective within nanometers, active interaction between SERS-active noble metals (gold and silver) and analyte molecules enhances the molecular detection capacity of SERS. However, neurotransmitters and noble metal nanoparticles are often not affinitive, because neurotransmitters generally have a hydroxyl group rather than a thiol group. As a result, the interaction between the two typically remains inactive, which makes detection more difficult. To overcome this limitation, in the present work we utilized metal-chelation to attract dopamine, a neurotransmitter molecule, close to the surface of silver nanoparticles. AgNS was capped with poly(vinyl alcohol) (PVA) and sequentially integrated with copper ion to bind dopamine in the form of chelate bonding between dopamine and copper. The PVA linked AgNS and metal ions through a coordinate bond between hydroxyl groups and metal ions. This metal-chelation-functionalized nanoprobe allowed us to stably detect dopamine in aqueous solution at a concentration of less than 10⁻⁶ M. Therefore, this method provides a convenient and easy-to-prepare option for the effective detection of dopamine, thus meaning it has the potential to be applied to other neurotransmitters.

中文翻译：

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使用金属螯合银纳米壳进行 SERS 检测多巴胺

由于不同神经递质的浓度可以表明某些影响大脑功能的疾病的存在，神经递质的定量分析在各个领域引起了越来越多的关注。表面增强拉曼散射 (SERS) 光谱是一种出色的光谱分析工具，能够在单分子水平上进行高特异性检测。由于表面等离子体的局部场增强在纳米范围内有效，SERS活性贵金属（金和银）与分析物分子之间的主动相互作用增强了SERS的分子检测能力。然而，神经递质和贵金属纳米粒子往往不具有亲和力，因为神经递质通常具有羟基而不是硫醇基。因此，两者之间的相互作用通常保持不活跃状态，这使得检测更加困难。为了克服这一限制，在目前的工作中，我们利用金属螯合来吸引多巴胺（一种神经递质分子）靠近银纳米粒子的表面。 AgNS 用聚乙烯醇 (PVA) 封端，然后与铜离子结合，以多巴胺和铜之间的螯合键的形式结合多巴胺。 PVA通过羟基和金属离子之间的配位键连接AgNS和金属离子。这种金属螯合功能化纳米探针使我们能够稳定检测浓度低于10 ^-6 M的水溶液中的多巴胺。因此，该方法为多巴胺的有效检测提供了方便且易于制备的选择，从而意味着它有可能应用于其他神经递质。