Application of Silver Nanostructures Synthesized by Cold Atmospheric Pressure Plasma for Inactivation of Bacterial Phytopathogens from the Genera Dickeya and Pectobacterium

Abstract

Pectinolytic bacteria are responsible for significant economic losses by causing diseases on numerous plants. New methods are required to control and limit their spread. One possibility is the application of silver nanoparticles (AgNPs) that exhibit well-established antibacterial properties. Here, we synthesized AgNPs, stabilized by pectins (PEC) or sodium dodecyl sulphate (SDS), using a direct current atmospheric pressure glow discharge (dc-APGD) generated in an open-to-air and continuous-flow reaction-discharge system. Characterization of the PEC-AgNPs and SDS-AgNPs with UV/Vis absorption spectroscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and selected area electron diffraction revealed the production of spherical, well dispersed, and face cubic centered crystalline AgNPs, with average sizes of 9.33 ± 3.37 nm and 28.3 ± 11.7 nm, respectively. Attenuated total reflection-Fourier transformation infrared spectroscopy supported the functionalization of the nanostructures by PEC and SDS. Antibacterial activity of the AgNPs was tested against Dickeya spp. and Pectobacterium spp. strains. Both PEC-AgNPs and SDS-AgNPs displayed bactericidal activity against all of the tested isolates, with minimum inhibitory concentrations of 5.5 mg∙L−1 and 0.75–3 mg∙L−1, respectively. The collected results suggest that the dc-APGD reaction-discharge system can be applied for the production of defined AgNPs with strong antibacterial properties, which may be further applied in plant disease management.

Enhanced Antibacterial Activity of Silver Doped Titanium Dioxide-Chitosan Composites under Visible Light

“…Also, Ag has strong antibacterial activities against both Gram positive and Gram negative bacteria, such as Staphylococcus aureus and Escherichia coli , which are common pathogens in water [26,27]. Moreover, the high specific surface area of Ag NPs makes it easier to release silver ions (Ag + ) and then kill the bacteria [28].…”

Evolving Technologies and Strategies for Combating Antibacterial Resistance in the Advent of the Postantibiotic Era

“…The species formed with CAP can be applied to synthesize biologically important nanomaterials or can be used with nanomaterials for antibacterial treatments 100. Recently, researches have been using plasma technology as a prominent “green” synthesis method for nanomaterials and investigating their antibacterial properties 101. A combination of nanomaterials and cold plasma is also gaining attention in order to provide synergistic effects and better treatment efficiency in biomedical applications 100,102.…”

Production of antimicrobial silver nanoparticles modified by alkanethiol self‐assembled monolayers by direct current atmospheric pressure glow discharge generated in contact with a flowing liquid anode

“…A convenient solution to the abovementioned problems can be to apply a cold atmospheric pressure plasma (CAPP)‐based bottom‐up approach, based on generation of selected reactive oxygen and nitrogen species along with hydrated electrons and H radicals, which are involved in reducing AgNPs precursor ions . CAPP‐based methods have been utilized for environment‐friendly AgNP production by several research groups . In the above‐cited studies, different CAPPs are operated either in liquids or in contact with liquids, but in all cases stationary (nonflow‐through) reaction‐discharge systems are used.…”

“…Ag nanostructures’ production via the CAPP‐based bottom‐up approach has been typically carried out in the presence of capping agents, preventing their sedimentation and aggregation . Natural stabilizers such as gelatin, dextran, pectins, sucrose, fructose, or surfactants like sodium dodecyl sulfate, have been used to stabilize NPs synthesized in CAPP‐based systems. Alkanethiols are example of ligands that have been used to cap versatile noble metal nanostructures produced with the aid of non‐CAPP based synthesis procedures .…”

“…TMA allows to obtain stable nanoparticles, as well as noncytotoxic AgNPs with antimicrobial potential . Previously, dc‐APGD or pulse‐modulated radio‐frequency atmospheric pressure glow discharge (pm‐rf‐APGD), operated between the surface of flowing liquid electrodes and pin‐type W electrodes or a gaseous nozzle jet, was used in our group to synthesize Ag or Ag‐Au core‐shell nanostructures. Until now, operating conditions for production of size‐defined Ag nanostructures have only been optimized for the pm‐rf‐APGD reaction‐discharge system; no dc‐APGD reaction‐discharge system has been previously been optimized for that purpose.…”