Hierarchical Ag Nanostructures Fabricated from Silver Coordination Polymers for Antibacterial Surface

Abstract

A hierarchical silver nanostructure with improved antibacterial property was fabricated utilizing silver coordination polymer. Octadecanethiolate–silver polymer was synthesized to have a layered structure and was coated on silicon wafer by drop-casting method utilizing hydrophobic–hydrophobic interaction. Thus, the silver coordination polymer was calcined under reductive condition to produce zero-valent silver with a hierarchical nanostructure. X-ray diffraction patterns revealed that layered silver coordination polymer successfully transformed to hexagonal silver upon calcination. According to scanning electron and atomic force microscopy, silver coordination polymer with ~145.5 nm size was homogeneously coated on the surface before calcination, and it evolved micrometer-sized lumps and grooves which were composed of ~58.8 nm sized Ag nanoparticles. The hierarchical structure—micrometer lump/groove consisting of Ag nanoparticles—would be advantageous to kill bacteria; micrometer-grooves provide physical condition (pocket for bacteria capture) and the Ag nanoparticles from the neighboring lump endow chemical condition (antibacterial property of released Ag+). The antibacterial activity test on Escherichia coli via colony forming inhibitory assay indeed exhibited an improved antibacterial activity of hierarchical Ag nanostructure compared with the surface simply coated with Ag nanoparticles. From the line profile of atomic force microscopy, the bacterium trapped in the hierarchical Ag nanostructure was shown to interact intimately with Ag surface.

Porous Hybrids Structure between Silver Nanoparticle and Layered Double Hydroxide for Surface-Enhanced Raman Spectroscopy

“…The evolution of mesopores at high temperature could be related to the reduction process of Ag-thiolate. According to our previous study, reductive calcination changed layered Ag-thiolate complex to zero valency Ag with various morphology depending on the substrate [ 52 , 53 ]. Free Ag-thiolate powder and Si wafer-coated Ag-thiolate resulted in fibrous silver and pebble-shaped silver particles, respectively.…”

Near-Infrared-Controlled Nanoplatform Exploiting Photothermal Promotion of Peroxidase-like and OXD-like Activities for Potent Antibacterial and Anti-biofilm Therapies

“…The final concentrations of WS 2 QDs in WS 2 QDs-Van@lipo was 50 μg/mL, and the H 2 O 2 concentration was 100 μM. After the treated bacterial suspension (100 μL) was spread on a solid medium and incubated at 37° C for 18 h, the CFU number was evaluated by the colony counting program of ImageJ software. , All experiments were repeated in parallel three times.…”

XFEL Microcrystallography of Self-Assembling Silver n-Alkanethiolates

“…Metal–organic chalcogenolates (MOChas) are self-assembling coordination polymers of a metal and an organic source of sulfur, selenium, or tellurium. Recently, compounds in this family have attracted interest for semiconducting properties, light–matter interactions, and catalytic activity. − Silver n- alkanethiolates − have drawn consistent interest as three-dimensional analogues to the well-studied self-assembled monolayers (SAMs) on silver and gold metal surfaces and for their antimicrobial activity . However, a lack of a single-crystal structure because of small crystal sizes is a common refrain in reports of these and related compounds.…”

“…1−11 Silver nalkanethiolates 12−16 have drawn consistent interest as threedimensional analogues to the well-studied self-assembled monolayers (SAMs) on silver and gold metal surfaces 17 and for their antimicrobial activity. 18 However, a lack of a singlecrystal structure because of small crystal sizes is a common refrain in reports of these and related compounds. Recently, we used small-molecule serial femtosecond X-ray crystallography (smSFX) to circumvent crystal growth challenges by performing serial crystallography directly on micro-and nanocrystalline powders in liquid phase injection media, without dehydration and vacuum exposure.…”