Recent Advances in Aggregation-Induced Emission Chemosensors for Anion Sensing

Abstract

The discovery of the aggregation-induced emission (AIE) phenomenon in the early 2000s not only has overcome persistent challenges caused by traditional aggregation-caused quenching (ACQ), but also has brought about new opportunities for the development of useful functional molecules. Through the years, AIE luminogens (AIEgens) have been widely studied for applications in the areas of biomedical and biological sensing, chemosensing, optoelectronics, and stimuli responsive materials. Particularly in the application of chemosensing, a myriad of novel AIE-based sensors has been developed to detect different neutral molecular, cationic and anionic species, with a rapid detection time, high sensitivity and high selectivity by monitoring fluorescence changes. This review thus summarises the recent development of AIE-based chemosensors for the detection of anionic species, including halides and halide-containing anions, cyanides, and sulphur-, phosphorus- and nitrogen- containing anions, as well as a few other anionic species, such as citrate, lactate and anionic surfactants.

Stimuli‐Responsive AIEgens

“…Actually, numerous AIE‐based fluorescent sensors have been reported for the detection of various anions, such as sulfur‐, phosphorus‐, and nitrogen‐containing anions, halides and halide‐containing anions, cyanides, etc. [ 207–209 ] Herein, we have taken a cyanide‐responsive example as the representative to illustrate the working principle involving typical Förster resonance energy transfer (FRET). [ 210 ] As illustrated in Figure a, Lin and co‐workers developed an amphiphilic AIE‐active copolymer (poly(NIPAM‐ co ‐TPE‐SP)) that consisting of an N ‐isopropylacrylamide (NIPAM) as the hydrophilic unit and a TPE−spiropyran (TPE‐SP) monomer as the bifluorophoric unit.…”

AIEgens: An emerging fluorescent sensing tool to aid food safety and quality control

“…Given its ultrastrong biotoxicity, the World Health Organization (WHO) has established the MRL level of 1.9 µM for cyanide in drinking water. Currently, the available sensing mechanisms for selective detection of CN − mainly include the coordination interaction, hydrogenbonding interaction, nucleophile addition reaction, and the supramolecular self-assembly (Chua, Shah, Zhou, & Xu, 2019). Among them, some strategies have also been used to explore a variety of AIE-based fluorescent sensors for monitoring CN − in drinking water.…”

Halogen Bonding Tetraphenylethene Anion Receptors: Anion‐Induced Emissive Aggregates and Photoswitchable Recognition

“…TPE derivatives have also received significant interest in the development of supramolecular sensors which couple a luminescent response with molecular recognition events [14–18] . However, the considered employment of TPE‐derivatives within supramolecular host systems remains scarce, [19–22] with the overwhelming majority of reported examples reliant on irreversible chemical modification of the AIEgen core to sense the guest species [23] …”