Highly Selective Fluorogenic Multianalyte Biosensors Constructed via Enzyme-Catalyzed Coupling and Aggregation-Induced Emission

Abstract

The development of a highly selective and fast responsive fluorogenic biosensor for diverse analytes ranging from bioactive small molecules to specific antigens is highly desirable but remains a considerable challenge. We herein propose a new approach by integrating substrate-selective enzymatic reactions with fluorogens exhibiting aggregation-induced emission feature. Tyrosine-functionalized tetraphenylethene, TPE-Tyr, molecularly dissolves in aqueous media with negligible fluorescence emission; upon addition of horseradish peroxidase (HRP) and H2O2, effective cross-linking occurs due to HRP-catalyzed oxidative coupling of tyrosine moieties in TPE-Tyr. This leads to fluorescence emission turn-on and fast detection of H2O2 with high sensitivity and selectivity. As a validation of the new strategy's generality, we further configure it into the biosensor design for glucose through cascade enzymatic reactions and for pathologically relevant antigens (e.g., human carcinoembryonic antigen) by combining with the ELISA kit.

Specific light-up bioprobes based on AIEgen conjugates

“…Upon incubation with ALP, the phosphate group was cleaved by hydrolysis reaction, yielding a hydrophobic product which emitted strongly in the same media. 38 The enzyme-catalysed coupling led to a significant fluorescence increase and has been exploited for the detection of H 2 O 2 , an important ROS and biomarker of many different bioprocesses. Based on a similar principle, a TPE probe with two phosphate groups was also designed for the ALP kinetic study as well as ALP quantification in both buffer and serum media.…”

An Enzyme‐Responsive “Turn‐on” Fluorescence Polymeric Superamphiphile as a Potential Visualizable Phosphate Prodrug Delivery Vehicle

“…The “turn‐on” system provides a different alternative which intuitively shows the existence of substances through fluorescence intensity changes . Especially for imaging analysis, the “turn‐on” fluorescence sensor is a superior solution . For example, Cheng and co‐workers built a real‐time drug‐reporting molecule (CPT‐SS‐CyN) composed of fluorescent cyanine‐amine dye (CyN), a disulfide linker, and camptothecin (CPT).…”

AIEgens for real-time naked-eye sensing of hydrazine in solution and on a paper substrate: structure-dependent signal output and selectivity

“…[12][13][14][15] Opposite to conventional fluorogens suffering from selfquenching, majority of AIEgens show very strong fluorescence in aggregated state or solid state but are almost non-emissive when molecularly dissolved because of the energy consumption of excited states by intramolecular motions. [16][17][18] Based on this unique optical property, a wealth of fluorescence turn-on AIE probes have been designed for the detection of small molecules, ions and biomacromolecules 12,14,[19][20][21][22][23][24][25][26][27][28] in solution phase. However, typical AIEgens are not suitable for solid-state light-up detection simply because they exhibit strong fluorescence once deposited on solid substrates, which is difficult to construct turn-on sensors.…”