Sensitivity of bacteria to diamond nanoparticles of various size differs in gram-positive and gram-negative cells

Abstract

In this study, the influence of the size and surface termination of diamond nanoparticles (DNPs) on their antibacterial activity against Escherichia coli and Bacillus subtilis was assessed. The average size and distribution of DNPs were determined by dynamic light scattering and X-ray diffraction techniques. The chemical composition of the DNPs studied by X-ray photoelectron spectroscopy showed that DNPs > 5 nm and oxidized particles have a higher oxygen content. The antibacterial potential of DNPs was assessed by the viable count method. In general, E. coli exhibited a higher sensitivity to DNPs than B. subtilis. However, in the presence of all the DNPs tested, the B. subtilis colonies exhibited altered size and morphology. Antibacterial activity was influenced not only by DNP concentration but also by DNP size and form. Whereas untreated 5-nm DNPs were the most effective against E. coli, the antibacterial activity of 18-50-nm DNPs was higher against B. subtilis. Transmission electron microscopy showed that DNPs interact with the bacterial surface, probably affecting vital cell functions. We propose that DNPs interfere with the permeability of the bacterial cell wall and/or membrane and hinder B. subtilis colony spreading.

Carbon Nanomaterials as Antibacterial Colloids

“…Shortly afterwards, Beranova et al demonstrated the inhibiting effects of detonation ND on E. coli growth [79]. The same authors reported that detonation NDs are antibacterial, while larger diamond nanoparticles obtained from milling are not [80]. This study lacked an explanation for the antibacterial properties of detonation ND, but it was suggested that untreated NDs are more effective in killing bacteria than the oxidized form.…”

Monitoring spin coherence of single nitrogen-vacancy centers in nanodiamonds during pH changes in aqueous buffer solutions

“…Nanodiamonds are biocompatible and are excellent NV carriers that can be delivered into complex biological structures including cells, organelles, and tissues [5,37,51,63]. This portability provides distinct advantages over bulk-diamond-NV centers in biological sensing.…”

Fluorescent nanodiamond‐bacteriophage conjugates maintain host specificity

“…There are advantages for using FNDs as opposed to another particle‐based labeling method, quantum dots (QD), for certain applications (Michalet et al, ). The FNDs have been reported to be generally non‐toxic, although poorly cleaned detonation nanodiamonds with varying sizes or with certain surface groups have been reported to have antibacterial properties (Beranova et al, ; Turcheniuk et al, ; Wehling, Dringen, Zare, Maas, & Rezwan, ). We use crushed high pressure high temperature (HPHT) nanodiamonds instead of detonation versions, which are cleaner to start with, then we do aggressive oxidative cleaning, which has been shown to attenuate toxicity (Materials and Methods).…”