Cui Yanyun, Zhao Jun, Li Huidan
College of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China.
Nanomaterials (Basel). 2023 Jul 23;13(14):2138. doi: 10.3390/nano13142138.
Alkaline phosphatase (ALP) is among the most studied enzymes by far, playing an important role in the metabolism of organisms and the regulation of protein activity. Herein, a label-free composite nanoprobe is constructed by combining inorganic nanomaterials and aggregation-induced emission (AIE) molecule to achieve highly sensitive and selective detection of ALP. Negatively charged 9,10-bis [2-(6-sulfonatopropoxyl) naphthylethenyl] anthracene (BSNVA) molecule is synthesized, which has the AIE performance and can be assembled on the surface of amino-SiO nanoparticles through electrostatic interaction for fluorescence enhancement. MnO nanosheets are rich in negative charges, enabling them to be wrapped on the surface of the amino-SiO nanosphere to shield the positive charge on its surface, making it impossible for BSNVA to accumulate on the surface and then weakening the bio-fluorescence of the system. Furthermore, with catalyzed substrates induced by ALP, generating ascorbic acid and the redox reaction between ascorbic acid and MnO, the nanoprobe helps in realizing the high-sensitivity detection of ALP with a detection limit of 0.38 mU/mL. The proposed strategy requires no complex cleaning and modification processes and can overcome the quenching effect caused by the aggregation of traditional organic dyes, proving to be a simple, low-cost and "turn-on" fluorescent detection method for ALP.
碱性磷酸酶（ALP）是迄今为止研究最多的酶之一，在生物体代谢和蛋白质活性调节中发挥着重要作用。在此，通过将无机纳米材料与聚集诱导发光（AIE）分子相结合，构建了一种无标记复合纳米探针，以实现对ALP的高灵敏度和选择性检测。合成了带负电荷的9,10-双[2-(6-磺丙氧基)萘乙烯基]蒽（BSNVA）分子，其具有AIE性能，可通过静电相互作用组装在氨基二氧化硅纳米颗粒表面以增强荧光。二氧化锰纳米片富含负电荷，能够包裹在氨基二氧化硅纳米球表面，屏蔽其表面的正电荷，使BSNVA无法在表面聚集，从而减弱体系的生物荧光。此外，在ALP催化底物生成抗坏血酸以及抗坏血酸与二氧化锰之间发生氧化还原反应的作用下，该纳米探针实现了对ALP的高灵敏度检测，检测限为0.38 mU/mL。所提出的策略无需复杂的清洗和修饰过程，能够克服传统有机染料聚集引起的猝灭效应，是一种用于ALP的简单、低成本且“开启型”荧光检测方法。
