Xie Xiangjun, Lian Yawen, Xiao Lehui, Wei Lin
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin 300071, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Oct 15;240:118594. doi: 10.1016/j.saa.2020.118594. Epub 2020 Jun 11.
β-Galactosidase (β-Gal), as a glycoside hydrolase, is closely associated with cell senescence and primary ovarian cancer. However, there is still lack of facile and rapid sensing approach to monitor the β-Gal activity. In this work, a label-free and convenient sensing strategy to detect β-Gal activity has been proposed based on fluorescent graphene quantum dots (GQDs). In the presence of β-Gal, 4-nitrophenyl-β-D-galactopyranoside (NPGal) can be hydrolyzed into 4-nitrophenol (4-NP), which serves as a good quencher to quench the fluorescence of GQDs. The quenching mechanism is proven to be inner filter effect (IFE). Due to the specificity of the enzymatic reaction, this sensing method displays excellent selectivity and high sensitivity. A broad dynamic range from 20 to 200 U L and a detection limit of 4.4 U L for the β-Gal assay are achieved. Compared with the previously reported methods, this sensing strategy only needs one fluorescent nanomaterial without any modification and avoids time-consuming handling steps. Therefore, the sensing strategy based on fluorescent GQDs offers great potential for the recognition of disease-correlated enzyme activity.
β-半乳糖苷酶（β-Gal）作为一种糖苷水解酶，与细胞衰老和原发性卵巢癌密切相关。然而，目前仍缺乏简便快速的传感方法来监测β-Gal活性。在这项工作中，基于荧光石墨烯量子点（GQDs）提出了一种无标记且便捷的检测β-Gal活性的传感策略。在β-Gal存在的情况下，4-硝基苯基-β-D-吡喃半乳糖苷（NPGal）可水解为4-硝基苯酚（4-NP），4-NP作为良好的猝灭剂可猝灭GQDs的荧光。猝灭机制被证明是内滤效应（IFE）。由于酶促反应的特异性，该传感方法具有出色的选择性和高灵敏度。实现了β-Gal检测的宽动态范围为20至200 U/L，检测限为4.4 U/L。与先前报道的方法相比，该传感策略仅需一种荧光纳米材料且无需任何修饰，避免了耗时的处理步骤。因此，基于荧光GQDs的传感策略在识别疾病相关酶活性方面具有巨大潜力。
