Recent advances in organic small-molecular dual-state emission probes

Organic small-molecule fluorescent probes play a pivotal role in fluorescence-based sensing applications, owing to their exceptional responsiveness to diverse stimuli. These probes can be classified into two categories based on their emission characteristics: those that emit strongly in isolated states and those that exhibit robust emission in densely packed states. While the former grapples with self-quenching issues, a phenomenon known as aggregation-caused quenching (ACQ), the latter triumphs over this challenge through aggregation-induced emission (AIE) properties. Nevertheless, both ACQ and AIE fluorophores are constrained to single emission states, necessitating the development of dual-state emission (DSE) fluorophores capable of emitting strongly in both isolated and aggregated states. DSE materials, unlike traditional fluorescent dyes, offer versatility across different phases, spanning from dilute solutions to solid states. They have demonstrated significant utility in biosensing and chemosensing, empowering the detection of various substances with exceptional sensitivity, specificity, and adaptivity. However, despite the remarkable progress achieved, a comprehensive understanding of the underlying mechanisms and the resolution of practical challenges remain ongoing endeavors. Future pursuits in molecular engineering, novel material development, and broader application exploration hold the key to fully harnessing the vast potential of DSE materials across diverse fields.