Bacterial Lysis via Photocatalysis ‐ A Critical Mechanistic Review

Abstract

This Review discusses one of the most important area of photocatalytic reactions. In current research scenario, photocatalysis is well utilized strategy for a wide variety of applications including organic/ inorganic decontamination, solar fuel generation, microbial disinfection etc. This Review touches upon the mechanistic aspect of microbial disinfection, the growth in the research, issues to be addressed in future to make it a sustainable technology for this application. This Review discusses the fundamental understanding of photocatalysis, important strategies to tune their optical properties to enhance the spectral range of absorption in visible and near infrared wavelength region. Various photocatalysis reports these days don't focus on the stability, reusability and recovery of the photocatalysts. However, these issues are very important to deal with for large scale viability of the process. Therefore, we have tried to address these issues along with the detailed experimental information and eliminate the misconceptions about bacterial disinfection. The details provided in this Review would help the researchers working in this area to a large extent and would open various questions for them to answer.

Optimal H2O2 concentration in advanced oxidation over titanium dioxide photocatalyst

“…Almost any organic compounds can be photooxidized on TiO2 surface to CO2 and H2O [2,[5][6][7][8]. Viruses and bacteria can be destroyed over the photocatalytic surface as well [9][10][11][12].…”

TiO2/Karaya Composite for Photoinactivation of Bacteria

“…The inactivation of S aureus strain bacteria could be explained by the oxidative action of the peptidoglycan layer and the E. coli strain by lipid peroxidation. Both produced reactive oxygen species when GKT was irradiated under light [47]. The TiO 2 /Karaya composite exhibited photoinactivation of around 40% against S. aureus and 70% against E. coli.…”

Update on Interfacial Charge Transfer (IFTC) Processes on Films Inactivating Viruses/Bacteria under Visible Light: Mechanistic Considerations and Critical Issues

“…The second stage involves bacteria reproduction to form a colony matrix, with this step being concomitant to the growth of an extracellular polymeric shell protecting the colony. In the third/last step, the colony attains its critical mass, ingests nutrients and eliminates metabolic residuals with a kinetics regulated by its enzymes [86]. (b) The degradation of recalcitrant biofilms occurs in different ways and is suggested next in Figure 12, involving several steps: (a) surface structural modification to preclude biofilm adhesion; (b) the use of bactericidal agents inducing quorum quenching/enzymatic/immunological disruption and (c) the use of catalysts under light or in the dark, leading to bacterial interference in the biofilm [87].…”