Kalaiyarasan Gopi, Veerapandian Murugan, JebaMercy Gnanasekaran, Balamurugan Krishnaswamy, Joseph James
Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India.
ACS Biomater Sci Eng. 2019 Jun 10;5(6):3089-3099. doi: 10.1021/acsbiomaterials.9b00394. Epub 2019 May 29.
A fluorescence active nanosystem capable of targeting specific receptors of cancer cells with or without a biorecognition element is advantageous for biosensor studies. Herein, a naturally occurring anticancer drug, amygdalin (synthetic form: Laetrile, a misnomer: vitamin B17), has been modified on the surface of carbon quantum dots, prepared by a hydrothermal method, to probe β-glucosidase activity. Despite its cyanide toxicity, amygdalin is recently revived to be an anticancer molecule, and the risk factor can be optimized by understanding its binding efficiency with β-glucosidase in the cancer cells. In this study, an biorecognition pattern of amygdalin-functionalized carbon quantum dots (Amy@CQDs) toward β-glucosidase is typically evaluated by an aggregation-induced fluorescence emission mechanism. The optical functionality and structural integrity of CQDs before and after functionalization with amygdalin are comprehensively studied by spectroscopic and microscopic techniques. Our results demonstrate that Amy@CQDs is a stable hydrophilic graphitic carbon nanostructure exhibiting selective fluorescence quenching upon interaction with β-glucosidase, enabling the lowest detection limit of 134 nM. Hydrolysis products of amygdalin mediated by β-glucosidase were further confirmed by HPLC and colorimetric methods, indicating the selective binding of the prepared Amy@CQDs, which may find a useful application in cancer diagnosis and therapeutics.
一种能够通过生物识别元件或不通过生物识别元件靶向癌细胞特定受体的荧光活性纳米系统，对生物传感器研究具有优势。在此，一种天然存在的抗癌药物苦杏仁苷（合成形式：莱tril，误称：维生素B17）已被修饰在通过水热法制备的碳量子点表面，以探测β-葡萄糖苷酶活性。尽管苦杏仁苷具有氰化物毒性，但最近它又重新成为一种抗癌分子，并且可以通过了解其与癌细胞中β-葡萄糖苷酶的结合效率来优化风险因素。在本研究中，通常通过聚集诱导荧光发射机制评估苦杏仁苷功能化碳量子点（Amy@CQDs）对β-葡萄糖苷酶的生物识别模式。通过光谱和显微镜技术全面研究了苦杏仁苷功能化前后碳量子点的光学功能和结构完整性。我们的结果表明，Amy@CQDs是一种稳定的亲水性石墨碳纳米结构，与β-葡萄糖苷酶相互作用时表现出选择性荧光猝灭，最低检测限为134 nM。通过HPLC和比色法进一步证实了β-葡萄糖苷酶介导的苦杏仁苷水解产物，表明所制备的Amy@CQDs具有选择性结合，这可能在癌症诊断和治疗中找到有用的应用。
