Metallothioneins (MTs) are important biomarkers for the early diagnosis of heavy metal poisoning and malignancies. Convenient and cost-effective approaches for the rapid detection of MTs are therefore highly desirable for clinical monitoring. Herein, by taking advantage of the enzyme-mimetic activity of nanoparticles and protein corona-based recognition, insufficient polyhedral oligomeric silsesquioxane (POSS) polymer-caged gold nanoparticles (denoted as PP-AuNPs) are developed for the sensitive colorimetric analysis of MTs. In the presence of MTs, the catalytic reduction of yellow 4-nitrophenol to colorless 4-aminophenol is inhibited due to masking of the exposed PP-AuNPs catalytic surface with MTs corona. MTs are quantified by the presented color contrast with a superior sensitivity up to a 1.5 nM detection limit. Most importantly, the heavy metal ion- and aptamer-free PP-AuNPs platform exhibits excellent selectivity toward MTs over various ions, neutral biomolecules, and protein species, and successful applications are demonstrated by the detection of MTs in complex biological samples.

中文翻译：

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POSS聚合物笼装的金纳米颗粒不足以对金属硫蛋白进行灵敏比色检测的蛋白质电晕引发的催化抑制作用。

金属硫蛋白（MTs）是早期诊断重金属中毒和恶性肿瘤的重要生物标志物。因此，对于临床监测非常需要用于快速检测MT的便捷且具有成本效益的方法。在此，通过利用纳米粒子的酶模拟活性和基于蛋白质电晕的识别，开发了不足的多面体低聚倍半硅氧烷（POSS）聚合物笼罩的金纳米粒子（表示为PP-AuNPs），用于MT的灵敏比色分析。在MTs的存在下，由于MTs电晕掩盖了暴露的PP-AuNPs催化表面，因此抑制了将4-硝基苯酚催化的黄色还原为无色的4-氨基苯酚。MTs可通过所呈现的颜色对比进行量化，并具有高达1.5 nM的检测极限的超高灵敏度。最重要的是，