Antibacterial effect of TiO₂:Cu:Ag thin coatings on Pseudomonas strain measured by microbiological and ATP assays

Abstract

The aim of this study is to investigate the antimicrobial properties of nanocomposite thin TiO2:Cu:Ag films on Pseudomonas putida as a natural isolate and an opportunistic pathogen. Several different methods were used to compare the antibacterial effect of thin TiO2:Cu:Ag layers obtained by radiofrequency magnetron sputter deposition against P. putida: optical density of the bacterial suspension, most probable number of survived cells, dehydrogenase activity inhibition, scanning electron microscopy images, atomic flame absorption spectroscopy, and adenosine triphosphate (ATP) luminescent assay. Optical density measurements and most probable plate count were in agreement and showed a strong bactericidal effect of the as‐deposited and only bacteriostatic effect of the annealed coatings with the same metal content on tested bacteria. As the metal quantity in the medium rises during the first hour of the experiment, it could be suggested that this is the main reason for cell death. ATP‐luminescent assay showed up to 18‐fold reduction of the signal. It was compared with other microbiological and biochemical assays to prove the strong antibacterial effect of nanocomposite thin TiO2:Cu:Ag coatings with the possibilities of medical applications. Protection of medical devices against infections is a significant current challenge raised by an increasing number of medical devices‐associated infections and microbial resistance to conventional antibiotic and multidrug treatments. Deposition of antimicrobial coatings is one of the current approaches to mitigate the problem.

Copper and Copper Nanoparticles Applications and Their Role against Infections: A Minireview

“…An enhanced antimicrobial effect was obtained with a combination of TiO 2 with CuO and two-layer structures of Ag and CuO in combination with TiO 2 . [57,[75][76][77]. Structures where Ag and CuO are inlaid on TiO 2 have higher biocidal activity.…”

Microfluidics for the rapid detection of Escherichia coli O157:H7 using antibody-coated microspheres

“…In the area of bacteria detection, the ATP luminescent method can be used to measure the amount of bacteria conveniently and quickly. In comparison with previous cell counting methods [ 22 ], this method has the advantages of simple operation and quick identification, and this method may have applications in clinical detection.…”