Femtosecond and Nanosecond Laser Irradiation to Enhance Antimicrobial Activity of α‑Ag 2-2x M x WO 4 (M x = Cu 0.15 and Zn 0.16 ) Microcrystals.

This study investigates the enhancement of the antimicrobial activity of α-Ag2-2x M x WO4 microcrystals, where M x represents Cu1.15 and Zn1.16, through femtosecond (fs) and nanosecond (ns) laser irradiation. The research highlights how laser exposure induces significant changes in the structural properties of the samples, as evidenced by the analysis of optical phonon modes, which indicate a loss of long-range ordered crystallinity in the irradiated materials. It was demonstrated that this lattice disorder increases the density of available free carriers, potentially enhancing the bactericidal performance of the materials. Furthermore, the study employs techniques such as transmission electron microscopy (TEM) and Fourier-transform infrared (FT-IR) spectroscopy to elucidate the structural order and cluster distortion due to dopant incorporation and laser treatment. The results reveal the presence of amorphous and nonstoichiometric nanoparticles formed during the laser irradiation process, which contributes to the overall enhancement of antimicrobial activity. This work provides a novel approach to improving the antimicrobial efficacy of α-Ag2-2x M x WO4 microcrystals, paving the way for future research in laser-modified materials to enhance biological activity.