دانلود رایگان مقاله انگلیسی پیشرفت هایی در غیر فعالسازی واکنش باکتریایی کاتالیزگر نوری کاتالیکتیک - الزویر 2019

ABSTRACT

The design, synthesis, fundamentals and evaluation of 2D/3D antimicrobial surfaces are addressed in detail in the current review. Recent advances in the antimicrobial mechanism, kinetics and properties of Ag, Cu and AgCu surfaces in the dark and under light irradiation are described and discussed. The structure-reactivity relations in the catalyst/photocatalyst layers were described by way of the surface characterization and the observed antibacterial kinetics. Escherichia coli (E. coli) and Methicillin resistant Staphylococcus aureus MRSA bacteria are selected as model pathogens to evaluate the antimicrobial inactivation kinetics. The separate antimicrobial properties of ions and the antimicrobial surface-contact effects are presented in a detailed way. The interfacial charge transfer (IFCT) mechanism and the identification of the most relevant reactive oxygen species (ROS) leading to bacterial disinfection are considered. The recently developed monitoring of the changes of the film surface potential (Eigenvalues) during bacterial inactivation and the redox reactions associated with catalyst/ photocatalyst surfaces are also presented. The potential for practical applications of these innovative 2D films and 3D sputtered medical devices in health-care facilities are accounted for in the present review.

Conclusions

One of the recent developments in photocatalyst involves the interfacial charge transfer through two or three binary oxides. This implies electrostatic attraction, van der Waals forces, and hydrophobic–hydrophilic interactions. Ag- and Cu-NPs/ions have been shown to diffuse trough the bacterial membrane through the cell wall porins damaging the cell. Metal/oxide surface-contact effects with the bacterial cell envelope are the other mechanism leading to bacterial inactivation. This proceeds through changes in the cell shape, surface potential, pH surrounding the bacteria, cell wall permeability and destruction of the bacterial cell wall functional groups. Cu- and Ag-NPs and recently more advanced Cu-Ag-NPs materials have been presented in this review. However, the full bactericidal inactivation mechanism is still not understood. The bacterial cell membrane is both a barrier and a channel for the inward and outward movement of chemical species with sizes below the porin diameters. In the gram-negative bacterial membrane structure, porins allow the passage of molecules < 600 Da, in and out of the bacteria. Standard methods of analysis are still needed allowing a quantitative comparison of the inactivation data obtained by different laboratories.