Exposure to trace amounts of lead is known to harm human health, especially for children, which results in irreversible detriment to brain and nerve development. However, most of the sensor platforms using the colorimetric method to detect lead (II) ions (Pb²⁺) are difficult to reach a decent limit of detection (LOD) and a large detection range. This work presents a practical method to detect Pb²⁺ in aqueous-medium with the help of single-particle dark field spectroscopy, which allows us to obtain good LOD and wide detection range. Our results illustrate that the glutathione functionalized AuNPs are able to capture free AuNPs in the presence of Pb²⁺ to form multipliers. Such a process results in a significant spectral redshift of scattering spectra due to plasmonic coupling, which allows us to reach a good LOD of 3.5 pM, and a large linear quantifiable detection range from 10 pM to 10 μM. The performance of our sensor platform provides an alternative way to detect traces of Pb²⁺ in real-life water samples.

已知微量的铅会危害人类健康，尤其是对儿童的健康，这会导致不可逆转的损害大脑和神经发育。但是，大多数使用比色法检测铅（II）离子（Pb ²⁺）的传感器平台很难达到像样的检测极限（LOD）和较大的检测范围。这项工作提出了一种借助单粒子暗场光谱法检测水性介质中Pb ²⁺的实用方法，这使我们可以获得良好的LOD和宽广的检测范围。我们的结果表明，在Pb ²⁺存在下，谷胱甘肽功能化的AuNPs能够捕获游离的AuNPs。形成乘数 由于等离子体耦合，这样的过程会导致散射光谱发生明显的光谱红移，这使我们可以达到3.5 pM的良好LOD，并且线性定量检测范围从10 pM到10μM。我们传感器平台的性能提供了另一种方法来检测现实生活中的水样中的痕量Pb ²⁺。