Green fabrication of quaternized chitosan/rectorite/Ag NP nanocomposites with antimicrobial activity

Abstract

Silver nanoparticles (Ag NPs) were synthesized rapidly in one pot via the Tollens reaction, in which quaternized chitosan (QCS) and rectorite (REC) acted as the reducing and stabilizing agent, while other chemical reducing and stabilizing agents and the surfactant were not included. X-ray diffraction, scanning electron microscopy and transmission electron microscopy results showed that spherical Ag NPs with uniform sizes were obtained, the layers of clay were peeled and thus exfoliated QCS/REC/Ag NP (QCRAg) nanocomposite was achieved. Moreover, Ag NPs dispersed well in the exfoliated nanocomposite matrix, some Ag NPs even entered into the interlayer of REC. QCRAg nanocomposites showed strong antimicrobial activity; the lowest minimum inhibitory concentration against Staphyloccocus aureus was only 0.0001% (w/v). The study reveals that the obtained QCRAg nanocomposites have great potential for biomedical applications.

Effect of rectorite on the synthesis of Ag NP and its catalytic activity

“…4 (b-3) and (c-3), which is corresponding to the XRD results. Silver nanoparticles load onto the layers, indicating the good support effect of rectorite for Ag NPs, and this is in accordance with our previous work [16]. Notably, some Ag NPs enter into the interlayers of the rectorite (as shown in Fig.…”

“…We have synthesized Ag NPs greenly and rapidly with quaternized carboxymethyl chitosan (QCMC) as reducing agent [15]. Our recent work [16] reported that more stable silver nanoparticles can be synthesized with rectorite as stabilizing agent and quaternized chitosan (QCS) as reducing agent, but the role of rectorite in the growth and property of silver nanoparticles was not completed displayed. Lin's work [17] showed the support effect of exfoliated clay nanoscale silicate platelets (NSP) for silver nanoparticle and the relationship between NSP and diameters of silver nanoparticles, however, it took two steps to get Ag NP/NSP nanohybrids and the explanation for NSP's influence on diameters of silver nanoparticles was not given.…”

One-pot green synthesis of antimicrobial chitosan derivative nanocomposites to control foodborne pathogens

“…This is similar to the in situ preparation of AgNPs in the presence of bagasse and modied chitosan/rectorite, which was reported in the literature. 39,40…”

Antimicrobial effect of PEG–PLA on food-spoilage microorganisms

“…Bacteria showed more sensitivity to PEG-PLA than other microorganisms used. Lou et al [25] reported that the inhibition activity of QCRAg nanocomposites (Quaternized chitosan with Ag NP) against gram-positive bacteria was the best and the smallest MIC value, while their inhibitory activity against fungus was the worst. This effect is due to differences in the cell structures of microorganisms.…”