The selective recognition of dopamine (DA) over other neurotransmitter analogues is difficult due to the similar molecular structure and chemical reactivity. In this study, substitution-regulated chemical reactivity of the sensing substrate is utilized to explore a novel DA detection probe with satisfying selectivity. As a case study, 3,5-dihydroxybenzoic acid (DHBA, carboxy-substituted resorcinol)-based probes have been explored for selective and ratiometric DA sensing. The carboxy substitution benefits the stabilization of the carbanion intermediate and the azamonardine product, which enhances the reaction kinetics and thermodynamics and subsequently facilitates selective DA recognition over other analogues and interferents. By exploring DHBA emission as the internal reference, ratiometric fluorescence variation is realized, which contributes to sensitive DA analysis. With the combination of logic gate and fluorometric analysis, DA detection in both low and high concentrations can be readily achieved. In addition, the DA analysis in biological samples and the enzymatic transformation of DA analogues in cerebrospinal fluid samples are achieved by the proposed DHBA probe.

中文翻译：

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通过取代增强动力学差异进行基于 3,5-二羟基苯甲酸的选择性多巴胺检测

由于相似的分子结构和化学反应性，多巴胺 (DA) 相对于其他神经递质类似物的选择性识别很困难。本研究利用传感底物的取代调节化学反应性来探索一种具有令人满意的选择性的新型DA检测探针。作为一个案例研究，基于 3,5-二羟基苯甲酸（DHBA，羧基取代的间苯二酚）的探针已被探索用于选择性和比例式 DA 传感。羧基取代有利于碳负离子中间体和氮杂莫纳定产物的稳定，从而增强反应动力学和热力学，并随后促进对其他类似物和干扰物的选择性 DA 识别。通过探索DHBA发射作为内参，实现了比率荧光变化，这有助于灵敏的DA分析。通过逻辑门和荧光分析的结合，可以轻松实现低浓度和高浓度的 DA 检测。此外，所提出的DHBA探针还实现了生物样品中的DA分析以及脑脊液样品中DA类似物的酶促转化。