A Fluorescent Visual Proton Donor and Photoacid Sterilant Based on Sulfonate‐conjugated BODIPY

Increasing acidity is an effective method for bacterial inactivation by inhibiting the synthesis of intracellular proteins at low pH. Photo-driven proton release probe can be used for the measurement of proton in hydrophobic condition. To develop fluorescent proton donor, two boron dipyrromethene derivatives (BDP-S and BDP-S2) were characterized by spectroscopic methods. Irradiation of BDP-S by white LED light resulted in efficient generation of acidic species with changes of fluorescence emission. The linear relationship between the pH value and the fluorescence intensity of BDP-S was obtained, indicating that BDP-S is a fluorescent visual proton donor. Light-induced antibacterial results indicate that BDP-S can significantly inhibit the growth of E. coli. The results prove that BDP-S is a very promising photoacid sterilant.