Abstract: To study the antibacterial activity and mechanism of tap (2,4,6-tris (Dimethylaminomethyl) phenol) zinc phthalocyanine photosensitizer against Escherichia coli (E.coli, ATCC 25922), the growth curve of E.coli was determined by UV, and the antibacterial activity of TAP zinc phthalocyanine photosensitizer on E.coli was studied by agar plate method. The metabolic activity was measured via the CCK-8 assay. The mode of action of tap zinc phthalocyanine photosensitizer was analyzed by ROS probe method (Quantifying ROS levels using DCFH-DA probe). Results showed that the logarithmic growth period of E.coli was about 4-10 h after inoculation. TAP zinc phthalocyanine photosensitizer had significant photodynamic antibacterial activity against E.coli, and its antibacterial effect was directly proportional to the concentration of photosensitizer. At the same time, it was proved that TAP zinc phthalocyanine photosensitizer played an antibacterial role by producing hydroxyl free radical singlet oxygen. This research proved that TAP zinc phthalocyanine photosensitizer had strong photodynamic antibacterial effect on E.coli, which provided evidence for the development-series of antibacterial products based on TAP zinc phthalocyanine photosensitize for antibacterial purpose.

Key words: TAP Zinc phthalocyanine, photosensitizer, E.coli, singlet oxygen, antibacterial activity