Tyrosinase (TYR) is an essential oxidase that is responsible for the regulation of multiple physiological processes and diseases. Achieving the trace and reliable detection of TYR in complex biological samples is of great significance for the diagnosis of TYR-related diseases, but which faces a great challenge. In this study, we developed an ingenious and powerful method for the ultrasensitive detection of TYR by click reaction-combined dark-field microscopy. This method begins with the formation of cuprous ions (Cu) based on the reduction of copper ions (Cu) by ascorbic acid (AA). Subsequently, the formed Cu can catalyze the crosslinking between azide- and alkyne-functionalized gold nanoparticles, causing a significant red-shift in the scattering spectrum. However, AA can chelate with TYR, which inhibits the generation of Cu and subsequent click reaction, thus achieving TYR-controlled scattering spectral shift. The proposed sensing platform shows a good linear detection range of 0.01–0.8 U/L with a low detection limit of 0.003 U/L, which is three orders of magnitude lower than the best performance of TYR sensing probes reported to date. Most importantly, the strategy has the ability to reliably and accurately detect TYR in serum sample, suggesting its potential clinical application in diagnosing TYR-related diseases. This visual sensing platform offers promising prospects for future research in enzymatic analysis and biomedical diagnostics.

中文翻译：

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点击反应结合暗场成像平台超灵敏检测酪氨酸酶

酪氨酸酶（TYR）是一种重要的氧化酶，负责调节多种生理过程和疾病。实现复杂生物样品中TYR的痕量、可靠检测对于TYR相关疾病的诊断具有重要意义，但面临着巨大的挑战。在这项研究中，我们开发了一种巧妙而强大的方法，通过点击反应结合暗场显微镜对 TYR 进行超灵敏检测。该方法首先通过抗坏血酸 (AA) 还原铜离子 (Cu) 来形成亚铜离子 (Cu)。随后，形成的铜可以催化叠氮化物和炔烃功能化的金纳米粒子之间的交联，导致散射光谱发生显着的红移。然而，AA可以与TYR螯合，从而抑制Cu的生成和随后的点击反应，从而实现TYR控制的散射光谱移动。所提出的传感平台显示出 0.01-0.8 U/L 的良好线性检测范围和 0.003 U/L 的低检测限，比迄今为止报道的 TYR 传感探头的最佳性能低三个数量级。最重要的是，该策略能够可靠、准确地检测血清样本中的 TYR，这表明其在诊断 TYR 相关疾病方面具有潜在的临床应用价值。该视觉传感平台为酶分析和生物医学诊断的未来研究提供了广阔的前景。