Self‐Assembled Monolayers of Silver Nanoparticles: From Intrinsic to Switchable Inorganic Antibacterial Surfaces

Abstract

The layer‐by‐layer technique allows to graft molecular monolayers on bulk surfaces that, in turn, allow to graft monolayers of metal nanoparticles. This microreview focuses on the preparation of such materials featuring a monolayer of silver nanoparticles (AgNP) and their use as antimicrobial surfaces against both planktonic bacteria and biofilms. The role of Ag+ release and of direct cell/AgNP contact in the antibacterial action will be stressed as a function of the adhesive molecular layer, of the AgNP dimension and shape, of their surface density, and of the molecular overcoating. While these surfaces display an intrinsic antibacterial action, a further evolution will also be reviewed, in which additional photothermal antibacterial action can be switched on demand, using near‐IR radiation and non‐spherical AgNP or a combination of AgNP with non‐spherical AuNP. The intrinsic and switchable photothermal action of these surfaces will be unraveled, and their synergistic effect stressed.

Synergistic Antibacterial Activity of Silver-Loaded Graphene Oxide towards Staphylococcus Aureus and Escherichia Coli

“…However, Ag NPs tend to agglomerate and are prone to oxidization, thus limiting the antibacterial effect. For instance, Ag NPs were found to be poorly dispersed in biological solution when grafted onto a titanium or silica substrate [18][19][20][21]. To overcome this problem, combining GO with Ag NPs facilitates the antibacterial properties.…”

Photothermally Active Inorganic Nanoparticles: from Colloidal Solutions to Photothermally Active Printed Surfaces and Polymeric Nanocomposite Materials

“…Photothermally active monolayers of gold nanostars on glass displayed antibacterial and antibiofilm activity upon NIR laser irradiation , . To introduce the remotely activated by NIR light nanocomposite materials with antibacterial properties, PVA films cross‐linked with citric acid containing highly photothermally efficient gold nanostars were fabricated and their antibacterial properties were studied .…”

Silver‐Infused Porphyrinic Metal–Organic Framework: Surface‐Adaptive, On‐Demand Nanoplatform for Synergistic Bacteria Killing and Wound Disinfection

“…Up to now, substantial efforts have been dedicated to develop new antimicrobial materials, such as nanozymes, metal nanoparticles, cationic polymer, and transition‐metal complexes . Among them, silver nanoparticles (Ag NPs) have been proved to be effective antibacterial agents with broad‐spectrum antimicrobial activity . Although the mechanism of antimicrobial effect is still not entirely known, Ag ions released from Ag NPs in water solution is believed to be toxic to microorganism by interacting with cell membranes and enzymes .…”