Energy transfer engineering based on fluorescent probes for directly sensing enzyme activities are in great demand as enzyme-mediated transformations, which are central to all biological processes. Here, a fluorescence carbon dot (CD)-based assay exhibiting selective responses to the quantitation of β-glucosidase and the effect of its inhibitor was developed. The most common substrate, para-nitrophenyl-β-d-glucopyranoside (pNPG) was hydrolyzed by β-glucosidase to release p-nitrophenol (pNP), which can efficiently quench fluorescence of CDs via an inner filter effect and electron transfer. However, in the presence of inhibitors of β-glucosidase, the fluorescence intensity gradually recovered as the concentration of inhibitors increased. Therefore, the enzyme-triggered fluorescence turn-off/turn-on of specific CDs successfully achieved sensitive detection of β-glucosidase and monitored the effect of its inhibitors. This new strategy was applied to detect β-glucosidase and monitor β-glucosidase inhibitor in hepatoma cells using cell imaging. All results suggest that the new method is sensitive and promising for use in cancer diagnosis and treatment.

中文翻译：

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酶触发的碳点荧光关闭/打开，用于监控活细胞中的β-葡萄糖苷酶及其抑制剂。

对于直接介导酶活性的基于荧光探针的能量转移工程，作为酶介导的转化，这是所有生物过程的核心，这是非常需要的。在这里，开发了一种基于荧光碳点（CD）的测定法，该测定法表现出对β-葡萄糖苷酶定量的选择性响应及其抑制剂的作用。最常见的底物对硝基苯基-β-d-吡喃葡萄糖苷（pNPG）被β-葡萄糖苷酶水解以释放出对硝基苯酚（pNP），后者可以通过内部滤镜效应和电子转移有效地猝灭CD的荧光。但是，在存在β-葡萄糖苷酶抑制剂的情况下，随着抑制剂浓度的增加，荧光强度逐渐恢复。所以，酶触发的特定CD的荧光关闭/打开成功实现了对β-葡萄糖苷酶的灵敏检测并监测了其抑制剂的作用。该新策略被用于通过细胞成像检测肝癌细胞中的β-葡萄糖苷酶并监测β-葡萄糖苷酶抑制剂。所有结果表明，该新方法灵敏且有望用于癌症的诊断和治疗。