Naslov
Probing the Mode of Antibacterial Action of Silver Nanoparticles Synthesized by Laser Ablation in Water: What Fluorescence and AFM Data Tell Us

Autori
Krce, Lucija ; Šprung, Matilda ; Rončević, Tomislav ; Maravić, Ana ; Čikeš Čulić, Vedrana ; Blažeka, Damjan ; Krstulović, Nikša ; Aviani, Ivica

Izvornik
Nanomaterials (2079-4991) 10 (2020), 6; 1040, 20

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
laser-synthesized nanoparticles ; silver nanoparticles ; mode of antibacterial action ; nano-bio interactions ; reactive oxygen species ; atomic force microscopy ; Young modulus

Sažetak
We aim to elucidate the mode of antibacterial action of the laser-synthesized silver colloid against Escherichia coli. Membrane integrity was studied by flow cytometry, while the strain viability of the treated culture was determined by plating. The spectrofluorometry was used to obtain the time development of the reactive oxygen species (ROS) inside the nanoparticle- treated bacterial cells. An integrated atomic force and bright-field/fluorescence microscopy system enabled the study of the cell morphology, Young modulus, viability, and integrity before and during the treatment. Upon lethal treatment, not all bacterial cells were shown to be permeabilized and have mostly kept their morphology with an indication of cell lysis. Young modulus of untreated cells was shown to be distinctly bimodal, with randomly distributed softer parts, while treated cells exhibited exponential softening of the stiffer parts in time. Silver nanoparticles and bacteria have shown a masking effect on the raw fluorescence signal through absorbance and scattering. The contribution of cellular ROS in the total fluorescence signal was resolved and it was proven that the ROS level inside the lethally treated cells is not significant. It was found that the laser-synthesized silver nanoparticles mode of antibacterial action includes reduction of the cell’s Young modulus in time and subsequently the cell leakage.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija, Biologija

Napomena
This article belongs to the Special Issue Safety and
Biocompatibility of Metallic Nanoparticles

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