In shell-isolated nanoparticle (NP)-enhanced Raman spectroscopy (SHINERS), traditional metal oxide-based shells have inferior chemical inertness, they require strict preparation conditions, and lack specific groups, which lead to their poor selectivity toward target molecules. In this study, ultrathin and compact gold (Au)@polydopamine (PDA) SHINERS NPs were successfully fabricated by a simple self-polymerization technique. High wrapping tendency of PDA, a multifunctional biopolymer, favored the fabrication process. Au@PDA NPs exhibited a typical shell-isolated effect, i.e., Au@PDA NPs with a thick shell (more than 2.3 nm) showed a lower SERS activity, while those with an ultrathin (1.3 nm) shell exhibited higher SERS activity compared to uncoated Au NPs. The Au@PDA SHINERS substrate shows high performance in terms of sensitivity, uniformity, and stability. The relative standard deviations (RSDs) of SERS intensities from ten positions on the same substrate were less than 4%. Their Raman intensities dropped by only 15% over two months. More importantly, the Au@PDA (1.3 nm) SHINERS substrate exhibited high SERS activity for label-free and quantitative detection of benzotriazole (BTA), an important corrosion inhibitor, through utilizing a presumed π–π stacking interaction. A broad linear range from 10⁻⁴ to 10⁻⁸ M was achieved with a low detection limit (LOD) of 1 nM (0.119 μg L⁻¹). The LOD was not only significantly lower than the maximum allowable level (20 μg L⁻¹) of the Australian government water guide, but also lower than that of some modern methods such as fluorescence, liquid chromatography, and gas chromatography coupled with mass spectrometry. Furthermore, the substrate showed excellent discrimination against other compounds with a single aromatic ring. It is expected that the Au@PDA SHINERS substrate will offer great potential for analysis application in a complicated environmental system.

中文翻译：

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超薄聚多巴胺薄膜包被的金纳米颗粒：灵敏，均匀且稳定的SHINERS底物，用于检测苯并三唑

在壳分离的纳米粒子（NP）增强拉曼光谱（SHINERS）中，传统的基于金属氧化物的壳化学惰性较弱，它们需要严格的制备条件，并且缺少特定的基团，这导致它们对目标分子的选择性差。在这项研究中，通过简单的自聚合技术成功地制造了超薄和致密金（Au）@polydopamine（PDA）SHINERS NP。多功能生物聚合物PDA的高包装趋势有利于制造工艺。Au @ PDA NPs具有典型的壳分离作用，即与未涂覆的Au NP相比，具有厚壳（大于2.3 nm）的Au @ PDA NPs表现出较低的SERS活性，而具有超薄壳（1.3 nm）的Au @ PDA NPs具有更高的SERS活性。Au @ PDA SHINERS基板在灵敏度，均匀性和稳定性方面显示出高性能。从同一基材上的十个位置开始，SERS强度的相对标准偏差（RSD）小于4％。他们的拉曼强度在两个月内仅下降了15％。更重要的是，Au @ PDA（1.3 nm）SHINERS基板通过假定的π-π堆积相互作用，对无标记的苯并三唑（BTA）（一种重要的腐蚀抑制剂）进行无标记和定量检测，显示出很高的SERS活性。从10 ^-4到10 ^-8的宽线性范围以1 nM（0.119μgL ^-1）的低检测限（LOD）达到M。LOD不仅显着低于澳大利亚政府水指南的最大允许水平（20μgL ^-1），而且还低于某些现代方法，例如荧光，液相色谱和气相色谱与质谱联用。此外，该基材对具有单个芳环的其他化合物表现出出色的辨别力。预计Au @ PDA SHINERS基板将为在复杂的环境系统中进行分析应用提供巨大潜力。