Mercury ion (Hg²⁺) is one of the most toxic heavy metals that has severe adverse effects on the environment and human organs even at very low concentrations. Therefore, highly sensitive and selective detection of Hg²⁺ is desirable. Here, we introduce plasmonic micropinball constructed from Au nanooctahedron as a three-dimensional surface-enhanced Raman spectroscopy (SERS) platform, enabling ultrasensitive detection of trace Hg²⁺ ions. Typically, strong SERS signals could be obtained when the single-stranded DNA structure converts to the hairpin structure in the presence of Hg²⁺ ions, due to the formation of thymine (T)–Hg²⁺–T. As a result, the detection limit of Hg²⁺ ions is as low as 1 × 10^–16 M, which is far below compared to that reported for conventional analytical strategies. Moreover, to achieve rapid multiple detection, we combine the micropinball sensors with microflow tube online detection. Our platform prevents cross-talk and tube contamination, allowing multiassay analysis, rapid identification, and quantification of different analytes and concentrations across separate phases.

中文翻译：

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用于汞离子的超灵敏金纳米八面体微弹球传感器

汞离子（Hg ²⁺）是毒性最高的重金属之一，即使浓度很低，也对环境和人体器官造成严重不利影响。因此，期望高度灵敏且选择性的Hg ²⁺检测。在这里，我们介绍由Au纳米八面体构造的等离子微弹球，作为三维表面增强拉曼光谱（SERS）平台，可以超灵敏地检测痕量Hg ²⁺离子。通常，由于存在胸腺嘧啶（T）–Hg ²⁺ –T ，当Hg ²⁺离子存在时单链DNA结构转变为发夹结构时，可以获得强SERS信号。结果，Hg ²⁺的检出限离子低至1×10 ^–16 M，与传统分析策略所报道的离子相比要低得多。此外，为了实现快速的多重检测，我们将微弹球传感器与微流管在线检测相结合。我们的平台可防止串扰和管子污染，从而允许进行多测定分析，快速鉴定和定量分析不同相中的不同分析物和浓度。