Sputter-Deposition of Silver Nanoparticles into Ionic Liquid as a Sacrificial Reservoir in Antimicrobial Organosilicate Nanocomposite Coatings

Abstract

We present a new approach for fabricating robust, regenerable antimicrobial coatings containing an ionic liquid (IL) phase incorporating silver nanoparticles (AgNPs) as a reservoir for Ag(0)/Ag(+) species within sol-gel-derived nanocomposite films integrating organosilicate nanoparticles. The IL serves as an ultralow volatility (vacuum-compatible) liquid target, allowing for the direct deposition and dispersion of a high-density AgNP "ionosol" following conventional sputtering techniques. Two like-anion ILs were investigated in this work: methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, [N(8881)][Tf(2)N], and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [emim][Tf(2)N]. Silver ionosols derived from these two ILs were incorporated into silica-based sol-gel films and the resultant antimicrobial activity evaluated against Pseudomonas aeruginosa bacteria. Imaging of the surface morphologies of the as-prepared films established a link between an open macroporous film architecture and the observation of high activity. Nanocomposites based on [N(8881)][Tf(2)N] displayed excellent antimicrobial activity against P. aeruginosa over multiple cycles, reducing cell viability by 6 log units within 4 h of contact. Surprisingly, similar films prepared from [emim][Tf(2)N] presented negligible antimicrobial activity, an observation we attribute to the differing abilities of these IL cations to infiltrate the cell wall, regulating the influx of silver ions to the bacterium's interior.

Matrix effect of montmorillonite and MCM-41 matrices on the antibacterial activity of Ag2CO3 nanoparticles

“…On the other hand, the small size of nanoparticles is the factor favoring their aggregation. The formation of nanoparticles agglomerates causes changes in their chemical, physical, and antibacterial properties (Hamm et al, 2012). To cope with these problems, appropriate supporting matrices must be found.…”

“…Mechanisms can arise from (i) Ag nanoparticles (NPs) uptake by the bacterial cells, (ii) presence of oxidatively released silver ions from nanoparticles surface, and (iii) nanoparticles generated reactive oxygen species (ROS) (Gottesman et al, 2011;Li et al, 2010;Chadeau et al, 2012;Hamm et al, 2012;Martínez-Gutierrez et al, 2012;Xiu et al, 2012).…”

Synthesis and antibacterial activity of surface‐coated catechol‐conjugated polymer with silver nanoparticles on versatile substrate

“…4 D-28359 Bremen, Germany) spectroscopy was performed using methanol-d 6 as the solvent. The C-PgP was characterized using UV-vis spectroscopy (Mecasys, Yuseong-gu Daejeon, South Korea) and FTIR spectroscopy (Thermo Scientific, Madison, WI USA), Nicolet 380].…”

“…These antibacterial materials can be produced in various forms and are easy to handle . [6][7][8][9][10][11][12] Unlike some other metals, Ag is not harmful to humans and is traditionally used in utensils and other household products. It also has excellent antibacterial activity.…”

“…Another mechanism that has been suggested involves the reaction of Ag + with bases on the DNA of microorganisms, hindering cell division. [6][7][8][9] Ag nanoparticles (AgNPs) and Ag-based antibacterial materials have therefore been widely studied and used as nanoagents for preventing bacterial resistance, because of their high antibacterial activities and wide antibacterial spectra. [10][11][12] The poly (propylene oxide) (PPO)-based structural material has been widely uses for the synthesis random and block copolymers as functional building block.…”