Biosensors for the Detection of Enzymes Based on Aggregation-Induced Emission

Abstract

Enzymes play a critical role in most complex biochemical processes. Some of them can be regarded as biomarkers for disease diagnosis. Taking advantage of aggregation-induced emission (AIE)-based biosensors, a series of fluorogens with AIE characteristics (AIEgens) have been designed and synthesized for the detection and imaging of enzymes. In this work, we summarized the advances in AIEgens-based probes and sensing platforms for the fluorescent detection of enzymes, including proteases, phosphatases, glycosidases, cholinesterases, telomerase and others. The AIEgens involve organic dyes and metal nanoclusters. This work provides valuable references for the design of novel AIE-based sensing platforms.

Advancements in Biosensors Based on the Assembles of Small Organic Molecules and Peptides

“…Moreover, hydrophilic peptides have been utilized as enzyme-responsive units and water-solubility promoters for the "turn-on" detection of other enzymes, including proteases, casein kinase II, furin, and autophagy-specific enzymes [147][148][149][150][151][152][153][154]. Several excellent review articles have extensively covered this topic, focusing on the AIE effect [155][156][157][158]. The AIE principle can be effectively combined with other photophysical quenching mechanisms, such as excited-state intramolecular proton transfer (ESIPT) and photoinduced electron transfer [159][160][161][162][163].…”

“…Moreover, hydrophilic peptides have been utilized as enzyme-responsive units and water-solubility promoters for the “turn-on” detection of other enzymes, including proteases, casein kinase II, furin, and autophagy-specific enzymes [ 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 ]. Several excellent review articles have extensively covered this topic, focusing on the AIE effect [ 155 , 156 , 157 , 158 ].…”

Chemical Tools to Image the Activity of PAR-Cleaving Proteases

“…In the latter case, FRET sensors can be either genetically encoded using fluorescent proteins or chemically synthesized using small molecule dyes . Aggregation-induced emission (AIE) probes, which include a lumogen that emits light only after proteolytic release and aggregation, are also in development for a number of proteases …”

“…22 Aggregation-induced emission (AIE) probes, which include a lumogen that emits light only after proteolytic release and aggregation, are also in development for a number of proteases. 23 The specificity of SBPs is variable. Often, the substrate recognition sequence is three to four amino acid residues long, allowing for limited contacts within the protease active site and thus limited opportunity to tailor specificity to individual proteases.…”

Quinoline-Malononitrile-Based Aggregation-Induced Emission Probe for Monoamine Oxidase Detection in Living Cells

“…Fluorescent materials are now crucial for biological investigation and clinical diagnosis since they offer dynamic and quantitative information about imaging biomolecules [ 17 , 18 , 19 ]. Because AIE materials exhibit turn-on fluorescence in aggregation while dim in solution [ 20 ], the fascinating AIE phenomenon in particular offers prospective advantages, especially in biosensing applications [ 21 , 22 , 23 , 24 ]. Due to its great sensitivity, the use of AIE fluorescent probes in conjunction with confocal imaging techniques is increasingly becoming more and more common for monitoring MAOs in living biosystems [ 25 , 26 , 27 ].…”