Selective Synthesis of Silver Nanoparticles onto Potassium Hexaniobate: Structural Organisation with Bactericidal Properties

Abstract

Silver-based nanocomposites are known to act as biocides against a series of microorganisms and are largely studied as an alternative to substitute conventional antibiotics that show decreasing efficacy. In this work, an eco-friendly method to synthesize silver nanoparticles assembled on the surface of hexaniobate crystals is reported. By means of ion exchange, K(+) ions of layered potassium hexaniobate were partially substituted by Ag(+) ions and the resulting material was exposed to UV light. The irradiation allowed the reduction of silver ions with consequent formation of silver nanoparticles located only on the hexaniobate surface, whereas Ag(+) ions located in the interlayer space remained in the ionic form. Increasing UV-light exposure times allowed controlling of the silver nanoparticle size. The antibacterial effects of the pristine potassium hexaniobate and of silver-containing hexaniobate samples were tested against Escherichia coli (E. coli). The antibacterial efficacy was determined to be related to the presence of silver in hexaniobate. An increasing activity against E. coli was observed with the decrease in silver nanoparticles size, suggesting that silver nanoparticles of distinct sizes interact differently with bacterial cell walls.

Tailored Silica–Antibiotic Nanoparticles: Overcoming Bacterial Resistance with Low Cytotoxicity

“…These results are in agreement with TEM images and DLS presented in Figure S1 in the Supporting Information and highlight the similarity of the samples size, which is desirable for comparing bacterial susceptibility tests. It is important to point out that samples with different sizes usually present distinct bactericidal properties. − Gaussian size distributions obtained from SAXS fittings are shown in Figure B. The half-width at half-maximum for SiO 2 -TC and bare SiO 2 are 3.90 and 3.51 nm, respectively.…”

Tailored Silica Nanoparticles Surface to Increase Drug Load and Enhance Bactericidal Response

“…In our previous works, [46][47][48][49][50][51][52][53][54] we investigated the correlation between the nanoparticles physical properties and their behavior in biological systems.These properties, that include size, surface charge and hydrophobicity, play an important role for the interaction between nanomaterials and biological systems. In the present study, we go further and show for the first time the bactericidal properties of amino-functionalized curcumin-loaded silica nanoparticles obtained from PSG method.…”

“…More recently, a plethora of works [39][40][41][42][43][44][45] demonstrating that surface-modified curcumin-loaded silica nanoparticles can be successfully and selectively used against different types of cancer cells were reported. However, to the best of our knowledge, nothing has been done in order to use nanostructured silica and curcumin (CCM) complexes as bactericidal agents.In our previous works, [46][47][48][49][50][51][52][53][54] we investigated the correlation between the nanoparticles physical properties and their behavior in biological systems.These properties, that include size, surface charge and hydrophobicity, play an important role for the interaction between nanomaterials and biological systems. In the present study, we go further and show for the first time the bactericidal properties of amino-functionalized curcumin-loaded silica nanoparticles obtained from PSG method.…”