Research Progress on Reactive Small Molecule Fluorescent Probes Based on the Formation and Cleavage of Covalent Bond

Fluorescent probes based on covalent bond formation and cleavage mainly undergo specific chemical recognition reactions between the probe and the analyte.After meeting with the analyte, the active chemical bonds in the original probe molecule undergo selective cleavage or substitution reaction, and new product changes the fluorescence signal (fluorescence intensity, emission wavelength, etc.) in the system, thereby achieving the detection of specific analytes.In recent years, these reactive fluorescent probes have received increasing attention due to their high specific selectivity, and sensitivity.Therefore, based on the different reaction modes between their active chemical bonds and analytes, these reactive small molecule fluorescent probes involving the formation and cleavage of covalent bond are further divided into two categories as decomposition type reaction and combination type reaction probes.According to this classification, the molecular design and synthesis of small molecule fluorescent probes based on covalent bond formation and cleavage, the mechanism of interaction with analytes, and various detection applications in detecting metal ions, inorganic anions, inorganic small molecules, organic small molecules, biologically active molecules, etc., are systematically reviewed, with a particular focus on summarizing their progresses in the past five years.Due to the fact that probes by the combination type reaction mechanism have both adsorption and removal functions, they are highly compatible with the current advocacy of green chemistry.Therefore, in the future, it is necessary to further expand the application fields of fluorescent probes based on covalent bond formation and cleavage, especially to strengthen the design and application of novel probes involving in the mechanism of the combination type reaction due to its being highly in line with the principles of green chemistry when the analyte is harmful.