A solution of identifying biophysical properties and 3D cellular structure of visible-light-driven photocatalytic inactivated Staphylococcus aureus

The mechanism of bacterial damage under visible-light-driven photo-inactivation system was attempted. Atomic force microscopy (AFM) and transmission X-ray microscopy (TXM) were firstly used to identify changes in biophysical properties, such as cellular height, roughness, adhesion, and modulus, and 3D cellular structure of microbial cells under visible-light-responsive N-TiO2 inactivation. Results revealed that the cell adhesion of NTiO2 occurred immediately upon light irradiation then N-TiO2 particles penetrated the cell membrane, and deformed the cellular structure at the beginning of log phase under photocatalytic inactivation. The destruction of the outer cellular caused leakage of cellular K+ and lipid peroxidation, which ultimately brought about severe decrease in cell density. AFM and TXM provided direct observations on interactions between single cell and nano-materials at the nanoscale, which was useful for the early diagnosis of cell damage.

Automated summary

The research revealed that cell adhesion and deformations in cellular structure are the main mechanisms of bacterial damage under visible-light-responsive N-TiO2 inactivation. Penetration of NTiO2 particles through the cell membrane leads to outer cellular destruction, resulting in leakage of cellular K+ and lipid peroxidation. AFM and TXM provide valuable insights into nanoscale interactions between single cell and nano-materials for early diagnosis of cell damage.