A Reversible Mechanochromic AIEgen Based on Triphenylamine for the Selective Detection of Vitamin B2 (Riboflavin) in Aqueous Media and Histotoxicity.

()-Ethyl 2-cyano-3-(4'-(diphenyl amino)-[1,1'-biphenyl]-4-yl) acrylate (RSJ) is a novel luminogen based on triphenylamine. It has been fully synthesized and characterized, exhibiting an incredible photophysical phenomenon known as aggregation-induced emission (AIE). This work describes a fluorescent sensor that detects vitamin B2 in mixed aqueous media with high selectivity and a low limit of detection as well as a mechanism for reversible mechanochromic luminescence. Moreover, the molecule was validated for its nontoxicity in water using a histotoxicological study. Fish subjected to two different concentrations of the "novel luminogen" that displayed photophysical phenomena during sensing of vitamin B2 (riboflavin) in mixed aqueous media did not exhibit any significant differences in the structural makeup of their liver, kidney, gills, brain, and muscle tissues when compared with the control group.