An innovative ratiometric surface-enhanced Raman scattering (SERS) sensor using a 4-mercaptoboric acid (4-MPBA)-modified silver nanoparticle-decorated silicon wafer (Si@Ag NPs chip) was proposed for the ultrasensitive determination of F- ions in aqueous solutions. The principle of sensing strategy is based on fluoride-induced structural symmetry breaking and charge redistribution of phenylboronic acid, leading to a band shift of the C-C stretching mode of 4-MPBA from 1589 to 1576 cm-1. Accordingly, a ratiometric signal of the area ratio (A1576/A1589) between the fluoride-bond MPBA molecules and unoccupied MPBA molecules can be used for the quantitative response of F- ions. In comparison with other SERS-based sensing methods, this ratiometric method can avoid a large error resulting from the inhomogeneity of substrates. Under the optimized analytical conditions, the proposed SERS sensor possesses a quick response to F- ions within 2 min and exhibits high selectivity for F- ions with the determination limit of 10-8 M, which is over 3 orders of magnitude lower than the World Health Organization (WHO) guideline value for F- ions in drinking water. Of particular significance, the present sensor features favorable recyclability, which preserves suitable reproducibility during 6-time cyclic determination of F- ions. The practical utility of this sensing system for the determination of F- ions was tested with real water and toothpaste samples, and the results demonstrate that this sensor shows high recoveries (90-110%). Given its simple principle and easy operation, the present silicon-based SERS sensor could serve as a promising sensor for various practical applications.

中文翻译：

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可重复使用的硅基SERS芯片，用于水溶液中氟离子的比例分析。

提出了一种创新的比例表面增强拉曼散射（SERS）传感器，该传感器使用4-巯基硼酸（4-MPBA）修饰的银纳米粒子修饰的硅晶片（Si @ Ag NPs芯片），用于超灵敏测定水溶液中的F-离子。解决方案。传感策略的原理基于氟化物引起的苯基硼酸结构对称性破坏和电荷重新分布，导致4-MPBA的CC拉伸模式从1589 cm-1到1576 cm-1的带移。因此，可以将氟化物键合的MPBA分子与未占据的MPBA分子之间的面积比（A1576 / A1589）的比例信号用于F离子的定量响应。与其他基于SERS的传感方法相比，该比率测量方法可以避免由于基材不均匀而导致的较大误差。在优化的分析条件下，建议的SERS传感器在2分钟内对F-离子具有快速响应，并且对F-离子具有高选择性，测定极限为10-8 M，比世界范围低3个数量级。卫生组织（WHO）饮用水中F-离子的准则值。特别重要的是，本传感器具有良好的可回收性，可在F离子的6次循环测定过程中保留适当的可重复性。用实际的水和牙膏样品测试了该传感系统测定F-离子的实际应用，结果表明该传感器显示出高回收率（90-110％）。鉴于其原理简单且易于操作，