A Versatile Crosslinking Strategy on Facile Fabrication of Fluorescent Hydrogels via o‐Phthalaldehyde Ternary Condensation.

Main observation and conclusion: It is of great significance to develop rapid crosslinking strategies to enrich the functions of hydrogels and simplify the preparation process of hydrogels. Herein, we applied the ternary condensation reaction of o‐phthalaldehyde (OPA) with thiol and amino moieties to construct hydrogel networks with fast gelation rate, excellent mechanical strength, and favorable stability. The obtained hydrogels exhibited rapid gelation transition even at a low solid content. The ternary condensation was traced in the gelation process and demonstrated as a pseudo‐first‐order reaction irrespective of the gelation threshold. Interestingly, the crosslinking sites of these hydrogels were constructed with isoindole rings, endowing the materials with fluorescent functions without an extra chemical grafting process. The OPA ternary condensation reaction was a simple and universal strategy towards fabrication of natural or synthetic polymer gels from polysaccharides, proteins, and synthetic polymers, which is expected to have potential biomedical applications. [ABSTRACT FROM AUTHOR]