In this study, we developed a new derivative-synchronous fluorescence spectroscopy enhanced surface plasmon coupled emission (DS-SPCE) technique for the detection of tannic acid (TA). DS-SPCE generates greatly amplified directional fluorescence signal, approaching nearly a 20-fold enhancement. The property of a gradual fluorescence quenching of the monolayer Rhodamine B isothiocyanate (RBITC) with increasing TA concentration was used for the quantitative detection of TA. The method achieved an ultra-low limit of detection (LOD) of 15.3 pM. It exhibited high selectivity for TA detection, even in the presence of common interferences such as glucose, catechin, and ascorbic acid at concentrations exceeding 100-fold. DS-SPCE method demonstrated robust performance in analyzing TA in tea samples, yielding good average recoveries of TA. Consequently, DS-SPCE emerges as a straightforward fluorescence enhancement approach, providing valuable insights for its practical application.

中文翻译：

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衍生同步荧光光谱增强表面等离子体耦合发射用于灵敏检测单宁酸

在这项研究中，我们开发了一种新的导数同步荧光光谱增强表面等离子体耦合发射（DS-SPCE）技术，用于检测单宁酸（TA）。 DS-SPCE 产生极大放大的定向荧光信号，增强接近 20 倍。利用单层罗丹明 B 异硫氰酸酯 (RBITC) 随着 TA 浓度的增加而逐渐荧光猝灭的特性，用于 TA 的定量检测。该方法实现了 15.3 pM 的超低检测限 (LOD)。即使存在浓度超过 100 倍的葡萄糖、儿茶素和抗坏血酸等常见干扰物，它也表现出对 TA 检测的高选择性。 DS-SPCE 方法在分析茶叶样品中的 TA 方面表现出强大的性能，并获得了良好的 TA 平均回收率。因此，DS-SPCE 作为一种简单的荧光增强方法出现，为其实际应用提供了宝贵的见解。