Synthesis and characterization of silver nanoparticle-decorated cobalt nanocomposites (Co@AgNPs) and their density-dependent antibacterial activity

Abstract

Magnetic cores loaded with metallic nanoparticles can be promising nano-carriers for successful drug delivery at infectious sites. We report fabrication, characteristic analysis and in vitro antibacterial performance of nanocomposites comprising cobalt cores (Co-cores) functionalized with a varied concentration of silver nanoparticles (AgNPs). A two-step polyol process synchronized with the transmetalation reduction method was used. Co-cores were synthesized with cobalt acetate, and decoration of AgNPs was carried out with silver acetate. The density of AgNPs was varied by changing the amount of silver content as 0.01, 0.1 and 0.2 g in the synthesis solution. Both AgNPs and Co-cores were spherical having a size range of 30–80 nm and 200 nm to more than 1 µm, respectively, as determined by scanning electron microscopy. The metallic nature and face-centred cubic crystalline phase of prepared nanocomposites were confirmed by X-ray diffraction. Biocompatibility analysis confirmed high cell viability of MCF7 at low concentrations of tested particles. The antibacterial performance of nanocomposites (Co@AgNPs) against Escherichia coli and Bacillus subtilis was found to be AgNPs density-dependent, and nanocomposites with the highest AgNPs density exhibited the maximum bactericidal efficacy. We therefore propose that Co@AgNPs as effective drug containers for various biomedical applications.

Endophytic Streptomyces laurentii Mediated Green Synthesis of Ag-NPs with Antibacterial and Anticancer Properties for Developing Functional Textile Fabric Properties

“…This electrostatic attractions destroys the selective permeability via the reacting of Ag-NPs with sulfur and phosphorylated proteins located in the bacterial cell wall causing partial dissolution of the cell membrane [ 48 ]. Nanoparticles enter the cell and causes the liberation of Ag + , which causes enhancement of the reactive oxygen species (ROS) that destroys the enzymes involved in cellular respiration and are ultimately responsible for cell death [ 49 ]. In the same context, Al-Dhabi et al [ 50 ] reported the extracellular synthesis of Ag-NPs from Streptomyces parvus with promising antibacterial activity against diverse pathogens involving S. aureus , S. epidermidi , E. faecalis , B. subtilis , P. aeruginosa , and E. coli .…”

Biosynthesis, characterization and anti-dengue vector activity of silver nanoparticles prepared from Azadirachta indica and Citrullus colocynthis

“…The colour of the reaction solution may change from transparent to light yellow to yellowish brown and finally dark brown depending upon the type of the extract used (as shown in figures 3 and 4 ). This time-dependent colour change during the synthesis (10 min for A. indica AgNPs and 20 min for C. colocynthis AgNPs), actually, indicates the different phases of nucleation and growth process occurring in the reactions [ 26 ]. The free silver atoms (Ag 0 ) accumulate due to van der Waals interactions and Brownian motion to form Ag-nuclei (nucleation process).…”

“…To determine the crystallite size ( D ) of both type of extract-mediated AgNPs, the width of prominent Bragg's reflection (111) in each case was used in the Debye–Scherer formula [ 26 ]. …”

<p>Extraction, Purification, and Characterization of Polysaccharides of <em>Araucaria heterophylla</em> L and <em>Prosopis chilensis</em> L and Utilization of Polysaccharides in Nanocarrier Synthesis</p>

“…11 They include metal nanoparticles like gold, silica, silver and magnetic iron oxide nanoparticles. 5,12,13 But the use of these metal nanoparticles as drug carriers can pose a threat of metal poisoning within the system. Some of the organically derived nanocarriers like polymeric micelles, liposomes, chitosan-based nanocarriers and polymeric nanogels are good for drug delivery.…”