The combination of surface-enhanced Raman scattering (SERS) and optical fiber has led to the development of SERS optical fiber probe, which demonstrates potential for real-time, in-situ, and flexible detection of water contamination. In this paper, a highly sensitive SERS optical fiber probe of gold nano-bipyramids (Au NBPs) was successfully developed for the first time. The Au NBPs were controllably synthesized by a heat-treated seed growth method. Surface modification of the Au NBPs was carried out by adding poly (sodium 4-styrenesulfonate) (PSS) instead of hexadecyl trimethyl ammonium bromide (CTAB), which changed the Zeta potential of the Au NBPs solution from positive to negative. The SERS properties of the Au NBPs can be significantly enhanced by optimizing the parameters of PSS content. The optical fiber end face was pretreated with silane coupling agent to introduce amino groups and exhibit positive charge. As a result, highly sensitive SERS optical fiber probes were prepared through electrostatic adsorption of the Au NBPs. The performance of the SERS optical fiber probe was evaluated. The crystalline violet (CV) limit concentration of 10 mol/L was detected by the optimized SERS optical fiber probe with satisfactory reproducibility and stability. Additionally, a limit concentration of 10 mol/L for thiram could also be detected by the SERS optical fiber probe. Finally, the SERS enhancement mechanism was further discussed. The finite element method was utilized to analyze the electromagnetic field distribution of Au NBPs, optical fibers, and SERS optical fiber probes, theoretically explaining the performance advantages of Au NBPs SERS optical fiber probes. Based on our results, the Au NBPs SERS optical fiber probe holds significant value for trace detection of water contamination and biomolecules.

中文翻译：

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具有 PSS 修饰金纳米双锥体的高灵敏度 SERS 光纤探针，用于水污染的痕量检测

表面增强拉曼散射（SERS）和光纤的结合促进了SERS光纤探头的发展，它展示了实时、原位、灵活检测水污染的潜力。本文首次成功研制出高灵敏度金纳米双锥体（Au NBPs）SERS光纤探针。 Au NBPs是通过热处理种子生长方法可控合成的。通过添加聚（4-苯乙烯磺酸钠）（PSS）代替十六烷基三甲基溴化铵（CTAB）对Au NBPs进行表面修饰，从而将Au NBPs溶液的Zeta电位从正变为负。通过优化 PSS 含量参数可以显着增强 Au NBP 的 SERS 性能。光纤端面用硅烷偶联剂进行预处理，引入氨基并呈现正电荷。结果，通过静电吸附Au NBPs制备了高灵敏度的SERS光纤探针。对SERS光纤探头的性能进行了评价。采用优化的SERS光纤探针检测结晶紫(CV)极限浓度为10 mol/L，具有良好的重现性和稳定性。此外，SERS光纤探头还可以检测到福美双的极限浓度为10 mol/L。最后，进一步讨论了SERS增强机制。利用有限元方法对Au NBPs、光纤和SERS光纤探头的电磁场分布进行了分析，从理论上解释了Au NBPs SERS光纤探头的性能优势。根据我们的结果，Au NBPs SERS 光纤探头对于水污染物和生物分子的痕量检测具有重要价值。