A new, simple, green, and one-pot four-component synthesis of bare and poly(α,γ,l-glutamic acid)-capped silver nanoparticles

Abstract

A simple and green chemical method has been developed to synthesize stable bare and capped silver nanoparticles based on the reduction of silver ions by glucose and capping by poly(α,γ,L-glutamic acid) (PGA). The use of ammonia during synthesis was avoided. PGA has had a dual role in the synthesis and was used as a capping agent to make the silver nanoparticle more biocompatible and to protect the nanoparticles from agglomerating in the liquid medium. The synthesized PGA-capped silver nanoparticles in the size range 5–45 nm were stable over long periods of time, without signs of precipitation. Morphological examination has shown that the silver nanoparticles had a nearly spherical, multiply twinned structure. The effects of the reaction temperature and the reaction time during the synthesis were investigated too. The biocompatibility of the PGA-capped silver nano-particles is discussed in terms of in vitro toxicity with human intestinal Caco-2 cells. The samples were characterized by UV–Visible spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and zeta potential measurements.

Multifunctional PLGA particles containing poly(l-glutamic acid)-capped silver nanoparticles and ascorbic acid with simultaneous antioxidative and prolonged antimicrobial activity

“…The UV-visible absorption spectra were shown to be relatively sensitive to the formation of silver colloids, as AgNps have an intense absorption band due to surface plasmon excitation [34]. The UV-visible absorption spectra of silver particles, synthesized using PGA as a capping agent, display a narrow surface plasmon absorption band at k = 408 nm [25] and the characteristic absorbance maximum for ascorbic acid is at 264 nm [26,29]. The degradation of PLGA and the release of AgNpPGA and ascorbic acid were tracked based on the intensity of the absorbance maximum which is correlated with the concentration of AgNpPGA and ascorbic acid within the solution.…”

“…PGA-capped AGNps were prepared according to the protocol described in our previouslwork [25]. AgNO 3 , glucose and poly(Lglutamic acid) served as a precursor, a reduction agent and a capping agent, respectively.…”

Antimicrobial activity of nano-sized silver colloids stabilized by nitrogen-containing polymers: the key influence of the polymer capping

“…The polymeric materials are used almost exclusively as stabilizers in the presence of different reducing agents. Polysaccharides, polycations, 23 polyamino acids 24 as well as other non-ionic water-soluble polymers 25 were successfully employed for such a purpose with resulting biological activity of the hybrid materials evaluated. Alternatively, when nitrogen-containing polymers are incorporated into the process, they can simultaneously act as reducing and stabilizer agent while imparting unique properties to the manufactured colloidal systems.…”

Molecular designing of nanoparticles and functional materials

“…50 A four--component method was used to synthesize poly(α,γ,L-glutamic acid)-capped silver nanoparticles with nearly spherical, multiply twinned structures, promising for a variety of applications, ranging from catalysis to electronics, surface plasmon resonance, and biomedical research. 51 Poly(α,γ,L-glutamic acid) was used as a capping agent to protect silver nanoparticles from agglomeration as well as to increase their biocompatibility. 52 An emulsifying procedure was used in combination with freeze-drying to prepare multifunctional PLGA spheres encapsulating poly(L-glutamic acid)-capped silver nanoparticles (AgNpPGA, Fig.…”