Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering , Shenzhen University , Shenzhen 518060 , China.
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute of Molecular Functional Materials, State Key Laboratory of Neuroscience, Division of Biomedical Engineering and Division of Life Science , The Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.
Acc Chem Res. 2019 Sep 17;52(9):2559-2570. doi: 10.1021/acs.accounts.9b00305. Epub 2019 Aug 22.
Fluorescent sensing has emerged as a powerful tool for detecting various analytes and visualizing numerous biological processes by virtue of its superb sensitivity, rapidness, excellent temporal resolution, easy operation, and low cost. Of particular interest is activity-based sensing (ABS), a burgeoning sensing approach that is actualized on the basis of dynamic molecular reactivity rather than conventional lock-and-key molecular recognition. ABS has been recognized to possess some distinct advantages, such as high specificity, extraordinary sensitivity, and accurate signal outputs. A majority of ABS sensors are constructed by modifying conventional fluorogens, which are strongly emissive when molecularly dissolved in solvents but experience emission quenching upon aggregate formation or concentration increase. The aggregation-caused quenching (ACQ) phenomenon leads to a limited amount of labeling of the analyte with the sensor and low photobleaching resistance, which could impede practical applications of the ABS protocol. As an anti-ACQ phenomenon, aggregation-induced emission (AIE) provides a straightforward solution to the ACQ problem. Thanks to their intrinsic advantages, including high photobleaching threshold, high signal-to-noise ratio, fluorescence turn-on nature, and large Stokes shift, AIE-active luminogens (AIEgens) represent a class of extraordinary fluorogen alternatives for the ABS protocol. The use of AIEgen-involved ABS can integrate the advantages of AIEgens and ABS, and additionally, the AIE process offers some unique properties to the ABS approach. For instance, in some cases of water-soluble AIEgen-involved ABS, chemical reaction not only leads to a chang in the emission color of the AIEgens but also causes solubility variations, which could result in specific "light-up" signaling. In this Account, the basic concepts and mechanistic insights of the ABS approach involving the AIE principle are briefly summarized, and then we highlight the new breakthroughs, seminal studies, and trends in the area that have been most recently reported by our group. This emerging sensing protocol has been successfully utilized for detecting an array of targets including ions, small molecules, biomacromolecules, and microenvironments, all of which closely relate to human health, medical, and public concerns. These detections are smoothly achieved on the basis of various reactions (e.g., hydrolysis, boronate cleavage, dephosphorylation, addition, cyclization, and rearrangement reactions) through different sensing principles. In these studies, the AIEgen-involved ABS strategy generally shows good biocompatibility, high selectivity, excellent reliability and high signal contrast, strongly indicating its great potential for high-tech innovations in the sensing field, among which bioprobing is of particular interest. With this Account, we hope to spark new ideas and inspire new endeavors in this emerging research area, further promoting state-of-the-art developments in the field of sensing.
荧光传感通过其超高的灵敏度、快速性、出色的时间分辨率、易于操作和低成本，已成为检测各种分析物和可视化众多生物过程的强大工具。特别值得关注的是基于活性的传感（ABS），这是一种新兴的传感方法，它是基于动态分子反应而不是传统的锁钥分子识别来实现的。ABS 已被证明具有一些独特的优势，例如高特异性、非凡的灵敏度和准确的信号输出。大多数 ABS 传感器是通过修饰传统的荧光团来构建的，这些荧光团在分子溶解在溶剂中时具有很强的发光性，但在聚集形成或浓度增加时会发生发光猝灭。聚集诱导猝灭（ACQ）现象导致传感器对分析物的标记量有限，而且光漂白抗性低，这可能会阻碍 ABS 协议的实际应用。作为对 ACQ 现象的一种反作用，聚集诱导发光（AIE）为 ACQ 问题提供了一个简单的解决方案。由于其内在的优势，包括高光漂白阈值、高信噪比、荧光开启性质和大斯托克斯位移，AIE 活性发光体（AIEgens）代表了一类用于 ABS 协议的非凡荧光团替代品。使用涉及 AIEgen 的 ABS 可以整合 AIEgen 和 ABS 的优势，此外，AIE 过程为 ABS 方法提供了一些独特的性质。例如，在某些水溶性 AIEgen 涉及的 ABS 情况下，化学反应不仅导致 AIEgen 的发射颜色发生变化，而且还导致溶解度的变化，这可能导致特定的“点亮”信号。在本账户中，简要总结了涉及 AIE 原理的 ABS 方法的基本概念和机制见解，然后重点介绍了我们小组最近报道的该领域的新突破、开创性研究和趋势。这种新兴的传感协议已成功用于检测包括离子、小分子、生物大分子和微环境在内的一系列目标，这些目标都与人的健康、医疗和公共利益密切相关。这些检测是基于各种反应（例如水解、硼酸酯裂解、去磷酸化、加成、环化和重排反应）通过不同的传感原理平稳实现的。在这些研究中，涉及 AIEgen 的 ABS 策略通常表现出良好的生物相容性、高选择性、出色的可靠性和高信号对比度，强烈表明其在传感领域的高科技创新方面具有巨大的潜力，其中生物探测特别引人注目。通过本账户，我们希望为这个新兴研究领域激发新的思路和新的努力，进一步推动传感领域的最新发展。
