Temperature-driven modulation of photoluminescence intensity in aggregation-induced emission-active molecules

Research on aggregation-induced emission (AIE) has gained significant attention owing to its application in various fields, including bioscience. However, achieving reversible luminescence and efficient quenching in practical applications is challenging. This study aims to address these challenges by developing a material based on a poly-N-isopropylacrylamide (PNIPA) gel, a biocompatible material, incorporating tetraphenylethylene, an AIE-active molecule. The photoluminescence (PL) intensity of the gel decreased to less than 30% in its dehydrated state compared with that in its hydrated state. The PL intensity decreased significantly near the lower critical solution temperature (307 K) of the PNIPA gel, indicating good response between quenching and luminescence. Notably, the resulting material exhibited reversible luminescence intensity. Overall, this technology can drive innovations in areas such as bioimaging and drug delivery. Achieving complete quenching in the shrunken state renders these applications more practical. To this end, further research is required to optimize both the dispersibility within shrunken gels and the cohesion within swollen gels. This study advances AIE material applications by proposing a viable strategy for dynamic PL modulation.