Achieving visual detection of analytes at ultra-low concentrations in complex mixtures remains a persistent challenge. While sophisticated techniques offer single-molecule sensitivity, practical hurdles remain, necessitating tailored signal amplification systems for direct visual detection. In this study, we develop a strategy for the visualized detection of tetrazine through a "click-release-oxidation-cycle" (CROC) cascade amplification process. We systematically describe the construction and synthesis of this system, the kinetic process of click release, the kinetics of oxidation to tetrazine and its cascade amplification effect in trace amounts of tetrazine. This system is capable of amplifying the signal of tetrazine at a concentration as low as 2 nM by 105-fold, thereby providing a clearly visible purple signal. Finally, as proof of concept, we successfully apply this method to visually detect trace β-galactosidase (β-gal) and Pd2+.

中文翻译：

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一种用于通过点击释放反应目视检测痕量分析物的 Tetrazine 扩增系统


在复杂混合物中实现超低浓度分析物的目视检测仍然是一个持续的挑战。虽然复杂的技术提供了单分子灵敏度，但实际障碍仍然存在，需要定制的信号放大系统进行直接视觉检测。在这项研究中，我们开发了一种通过 “click-release-oxidation-cycle” （CROC） 级联扩增过程可视化检测 tetrazine 的策略。我们系统地描述了该系统的构建和合成、点击释放的动力学过程、氧化成四嗪的动力学及其在痕量四嗪中的级联扩增作用。该系统能够将浓度低至 2 nM 的 tetrazine 信号放大 105 倍，从而提供清晰可见的紫色信号。最后，作为概念验证，我们成功地应用该方法目视检测痕量 β-半乳糖苷酶 （β-gal） 和 Pd2+。