Synergy of different fluorescent enhancement effects on spiropyran appended onto cellulose

An excellent fluorescent material derived from spiropyran species was facilely fabricated by appending spiropyran onto the cellulose matrix via a covalent link of an ester carbonyl group. The interior high-polar environment in the porous cellulose matrix can promote the concentration of the merocyanine form; the conformational constraint of cellulose cavities and the elimination of solvent influence can sufficiently develop the quantum yield of merocyanine. In contrast with other spiropyran materials, the synergy of the three different effects can significantly enhance the fluorescent intensity of the spiropyran compound by 1 order of magnitude approximately. These experimental results may bring about more promising applications of spiropyran species beyond their photochromic properties.