Silver Nanoparticles Obtained by Semicontinuous Chemical Reduction Using Carboxymethyl Cellulose as a Stabilizing Agent and Its Antibacterial Capacity

Abstract

Preparation of silver nanoparticles was carried out by semicontinuous reduction of Ag + ions at low temperatures. Silver nitrate was used as the Ag 0 precursor, the carboxymethyl cellulose (CMC) as stabilizer and primary reducing agent, and sodium borohydride as reducing agent. Weight ratios of 1 : 1 and 1 : 2 of AgNO 3 : CMC were used for carrying out the reactions. Silver nanoparticles were characterized by UV-VIS spectroscopy, transmission electronic microscopy (TEM), and X-ray diffraction (XRD). The formation of silver nanoparticles was confirmed by XRD spectroscopy and by the presence of an absorption peak around 400 nm in the UV-visible spectrum. Unimodal size distributions of spheroidal nanoparticles were observed by TEM. Greater productivities than those reported by other authors were obtained with the advantage of using a lower temperature and minor reaction times. By using a higher CMC/AgNO 3 weight ratio or a higher concentration of AgNO 3 , AgNPs with larger average size were produced. Antibacterial activity of AgNPs against S. aureus and E. coli was determined by the agar disk diffusion method. The higher the AgNPs concentration, the larger the inhibition zone. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus and E. coli was 5 g/disk.

Biosynthetic Conversion of Ag+ to highly Stable Ag0 Nanoparticles by Wild Type and Cell Wall Deficient Strains of Chlamydomonas reinhardtii

“…The SPR peak for algal-synthesized AgNPs at 420 nm has been reported previously [15,60]. According to Figure 2, each spectrum has a bell shape indicating that the AgNPs were spherical [61]. Additionally, at the higher concentration (1.250 mM), the SPR peak displayed a shoulder at ~490 nm that may be attributed to the strong interaction between the particles [62] or as a result of a heterogeneous AgNP size distribution [63].…”

Fabrication of Silver Nanoclusters and Nanocomposite Films Based on Coordinated Electrodeposition of Carboxymethyl Cellulose

“…[52,54] Pedroza-Toscano et al synthesized silver nanoparticles using CMC as the stabilizer and reducing agent, and they proposed that Ag + ions could couple with hydroxyl groups (R-OH or R-CH 2 -OH) of CMC, leading to the release of electrons from these groups and the reduction of Ag + ions. [55] Therefore, during the electrodeposition and the subsequent incubation the reducing hydroxyl groups of CMC macromolecules can reduce Ag + in the electrodeposited film to Ag (0), so that AgNCs are generated in the film. At the same time, CMC macromolecules can also act as the stabilizing agent to prevent the aggregation of the resulting AgNCs.…”

Silver Nanoparticle-Embedded Nanogels for Infection-Resistant Surfaces

“…CMC is a modified derivative of cellulose, which contains carboxymethyl groups in the place of the hydroxyl group . Being an anionic polymer, CMC stabilizes the NPs and acts as a reducing agent . AgNP-loaded CMC hydrogels have been prepared, where trisodium citrate and epichlorohydrin were utilized as reducing agents .…”

“…21 Being an anionic polymer, CMC stabilizes the NPs and acts as a reducing agent. 22 AgNP-loaded CMC hydrogels have been prepared, where trisodium citrate and epichlorohydrin were utilized as reducing agents. 23 Similarly, AgNP-loaded CMC hydrogels were prepared, where CMC was used as the reducing agent and as a stabilizing agent.…”