TPE based aggregation induced emission fluorescent sensors for viscosity of liquid and mechanical properties of hydrogel

Two amphiphilic TPE E/Z isomers with aggregation induced emission (AIE) property have been synthesized and characterized. The logarithmic fluorescent intensity of the two molecules was in positive relationship with logarithmic viscosity of liquid. To note, the Z-TPE isomer exhibited more sensitivity in the viscosity of liquid sensing in comparison with the corresponding E-TPE counterpart (around 1.80 folds). Furthermore, two molecules could be used as fluorescent sensors for mechanical properties (viscosity and storage modulus) of hydrogel as well. In addition, two sensors displayed low cytotoxicity in normal tissue cell line (L929) within the concentration range of 2–10 µmol/L. These results potentially promised their applications as fluorescent sensors for mechanical properties in the fields of biological and biomedical.