A Dynamically Responsive Chemosensor That Can be Modulated by an Effector: Amplification Sensing by Positive Heterotropic Allosterism

Induced-fit chemosensors that can control their molecular recognition behavior using external stimuli such as temperature, light, pH, and chemical additives, have attracted much attention from several chemists. In this study, we report a bisporphyrin-bisthiourea-binaphthyl conjugated chemosensor that can be modulated using a chiral dianion. The optical properties of the chemosensor measured using fluorescence and UV/vis absorption spectroscopies, as well as fluorescence lifetime measurements, indicated that the unique conjugation enabled S-2 fluorescence. The binding constants of the chemosensor for amino acids were amplified a thousand-fold compared to that of the reference compound due to positive heterotropic allosterism. The present study provides new perspectives for signal amplification of chemosensors by allosterism.