The increasing prevalence of infectious diseases in recent decades has posed a serious threat to public health. Routes of transmission differ, but the respiratory droplet or airborne route has the greatest potential to disrupt social intercourse, while being amenable to prevention by the humble face mask. Different types of masks give different levels of protection to the user. The ongoing COVID-19 pandemic has even resulted in a global shortage of face masks and the raw materials that go into them, driving individuals to self-produce masks from household items. At the same time, research has been accelerated towards improving the quality and performance of face masks, e.g., by introducing properties such as antimicrobial activity and superhydrophobicity. This review will cover mask-wearing from the public health perspective, the technical details of commercial and home-made masks, and recent advances in mask engineering, disinfection, and materials and discuss the sustainability of mask-wearing and mask production into the future.

This review summarizes recent advances in AIE-based chemosensors for the detection of a wide range of metal cations, outlining the various sensing mechanisms and sensing performances such as sensitivity and selectivity of AIE-based chemosensors.

This review is to summarize the latest progress on aggregation-induced-emission (AIE)-active polymers for explosive detection.

This review provides an overview of the progress in the development of AIE-based organic small molecule probes for detecting biologically important molecules, drug molecules, volatile organic compounds, and explosives over the past five years.

Acrylate monomers with aggregation-induced emission (AIE) attributes were prepared by reacting 4-(1,2,2-triphenylvinyl)phenol with 1-bromoalkan-1-ol, followed by the treatment with acryloyl chloride in the presence of a base. The resulting acrylate monomers were polymerized by free radical polymerization to give very high molecular-weight AIE-active polymers (400 000–650 000) with low polydispersity indices (1.28–1.51). Thermal stabilities of the AIE polymers are comparable to that of poly(methyl methacrylate) (PMMA), while their glass transition temperatures are 50–70 °C lower than that of PMMA. The AIE polymers are soluble in common organic solvents and have outstanding film-forming ability. Most importantly, the polymers in the mixtures of THF–H₂O can form extremely stable nanoparticles, with no tendency towards agglomeration at 4 °C for over nine months. The polymers exhibit much more significant AIE activity than their monomers and their precursor 4-(1,2,2-triphenylvinyl)phenol in THF–H₂O mixtures. Fluorescence of the polymers in THF–H₂O mixtures and in the film state can be dramatically quenched by a wide variety of nitro compounds, including picric acid, 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, 4-nitrophenol, 4-nitrotoluene, nitromethane and nitrous sulfuric anhydride. The AIE polymers show no response to the reference compounds toluene and phenol. These AIE polymers are thus potential fluorescence sensors for nitroaromatic explosives.