Table 1.

Metal and metal oxide nanoparticles antibacterial mechanism and common production method

Metal NPs	Antibacterial mechanism	Common production method	Refs
AuNPs	By causing the formation of perforations in the bacterial cell wall, AuNPs exert their antibacterial effect, manifesting in cell demise and the subsequent loss of cellular contents	One of the most well-known methods for the synthesis of AuNPs, the Turkevich method, was developed by Turkevich in 1951 and relies on the reduction of HAuCl4 by citrate in water	[114, 115]
AgNPs	AgNPs are capable of penetrating bacterial cell walls, thereby altering the configuration of cell membranes and potentially inducing cellular demise. By releasing silver ions, they are capable of increasing the permeability of cell membranes, generating reactive oxygen species (ROS), and interfering with the replication of deoxyribonucleic acid	The categorization of current synthesis methods can be delineated into two distinct types: bottom-up and top-down. The top-down approach involves the utilization of diverse physical forces—including mechanical influences (e.g., crushing, grinding, and milling); electrical forces (e.g., electrical arc discharge or laser ablation); and thermal forces (e.g., vapor condensation—to generate metal NPs from bulk materials. The bottom-up approach involves the nucleation and proliferation of molecular components to form complex aggregates. Chemical and biological synthesis are prevalent bottom-up approaches to produce NPs from precursor salts	[116, 117]
MNPs	The antibacterial mechanisms exhibited by magnetic nanoparticles (MNPs) are believed to result from two factors: Activation of ROS on the surfaces of the NPs induces oxidative stress within the bacterial cell, leading to cellular demise	The process of producing Fe2O3-NPs was carried out via hydrothermal means. The procedure entailed the dissolution of 0.85 mg of FeCl3.6H2O in 100 mL of double-distilled water within a 250 mL round-bottom flask. This was followed by 45 min of magnetic agitation at 85 °C at 800 rpm	[118, 119]
CuNPs	CuNPs are exceptionally reactive by their high surface area to volume ratio, which enables them to interact profusely with the cell membrane, thereby causing cell mortality by damaging cellular genetic materials	The present inquiry pertains to the environmentally friendly production of CuNPs using two distinct techniques: (I) a time-based approach and (II) thermal treatment of an aqueous solution. The plant extract in question is Moringa oleifera Lam	[120, 121]
TiONPs	The antimicrobial action of TiO2 is frequently attributed to ROS that generate a charge-inducing charge in the presence of O2 due to band-gap irradiation. ROS kills bacterial cells via a variety of mechanisms by which they react	Molten matrix sputtering (MMS) produced a transparent resin comprising titanium oxide NPs. To acquire homogenous dispersions of NPs, the low vapor pressure of the liquid pentaerythritol ethoxylate (PEEL) substrate enables the direct application of this vacuum technique to liquid PEEL while agitating	[122, 123]
ZnO NPs	The antibacterial properties of ZnO NPs are appealing, which can be attributed to their increased specific surface area and improved particle surface reactivity resulting from the reduced particle size	ZnO NPs were synthesized by a hydrothermal process employing sodium hydroxide and Zn nitrate hex-hydrate	[124, 125]