Aggregation induced emission controlled by a temperature-sensitive organic–inorganic hybrid polymer with a particular LCST

Abstract

In this study, an organic–inorganic temperature-sensitive polymer encapsulating tetraphenylethene (TPE) was designed. Its fluorescence intensity is sensitive to temperature changes and reaches a maximum at normal cell temperature. Firstly, the organic–inorganic hybrid polymer, polyhedral oligomeric silsesquioxane-based-poly(N-isopropylacrylamide) (POSS-b-PNIPAM) with a particular LCST of 37.5 °C, was synthesized by atom transfer radical polymerization. POSS-b-PNIPAM self-assembled in aqueous solutions to form stable micelles and then TPE was assembled into the micelles in water. The fluorescence intensity of TPE encapsulated in POSS-b-PNIPAM can be tuned by changing the temperature. The fluorescence intensity of TPE encapsulated in POSS-b-PNIPAM reached a maximum at 37 °C, which is much higher than the TPE fluorescence intensity at the same temperature. TPE encapsulated in POSS-b-PNIPAM still showed high fluorescence intensity after entering HeLa cells at 37 °C.