Novel photofluorochromic materials based on GFP chromophore like analogues for cells imaging and photo-patterning

Photoswitches with multiple fluorescent states known as photofluorochromism under light irradiation show practical applications in optical information storage, anticounterfeiting, and sensors. Despite considerable progress, current photoresponsive systems mainly operate in solution phase, with solid-state implementations remaining challenging. Herein, in this article, we reported three green fluorescent protein (GFP) chromophore like analogues (denoted as p -CBIE, m -CBIE and m -DCBIE) demonstrating photofluorochromic behavior in solid-state. Intriguingly, these compounds exhibited opposite photo responses between solution and solid states. In solution phase, UV irradiation induced fluorescence quenching through photoisomerization. Remarkably, the solid-state displayed light-activated fluorescence enhancement with chromatic shifts: p -CBIE and m -DCBIE exhibited green-to-blue emission switching with fluorescence quantum yield (Φ F ) enhancements from 8.2 % to 18.2 % and 11.3 % to 25.8 %, respectively. m -CBIE demonstrated blue emission increase with Φ F improvement from 4.8 % to 16.6 %. Mechanism studies revealed that light-induced molecular reorganization facilitated tighter packing and enhanced structural rigidity in the solid state, thereby suppressing non-radiative decay pathways. Moreover, p -CBIE, m -CBIE and m -DCBIE were successfully used for selective photoactivation imaging of SK-OV-3 cancer cells and photo-patterning.