Biosynthesis of gold nanoparticles using chloroplasts

Abstract

Abstract:In this paper, a new method of one-pot biosynthesizing of gold nanoparticles (GNPs), using chloroplasts as reductants and stabilizers is reported. The as-prepared GNPs were characterized by ultraviolet visible spectroscopy, transmission electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy (FTIR). The cytotoxicity of the GNPs was evaluated using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against gastric mucous cell line GES-1 and gastric cancer cell line MGC-803. Rhodamine 6G as a Raman probe was used for investigating surface-enhanced Raman spectroscopy (SERS) enhancement of GNPs. The transmission electron microscopy results indicated that the GNPs were spherical in structure and almost 20 nm in diameter. Ultraviolet visible spectroscopy exhibited an absorption peak at 545 nm. The GNPs exhibited high crystallinity, with the (111) plane as the predominant orientation, clarified by X-ray powder diffraction. In addition, a potential mechanism was proposed to interpret the formation process of GNPs, mainly based on the analysis of FTIR results. The FTIR spectrum confirmed that the GNPs were carried with N-H groups. Toxicological assays of as-prepared GNPs revealed that the green GNPs were nontoxic. SERS analysis revealed that the GNPs without any treatment could substantially enhance the Raman signals of rhodamine 6G. The Raman enhancement factor was calculated to be nearly 10 10 orders of magnitude. In conclusion, the GNPs with good biocompatibility and excellent SERS effect were successfully synthesized using chloroplasts. These biogenetic GNPs have great potential for ultrasensitive detection of biomarkers in vitro and in vivo based on SERS.

The ways to increase efficiency of soil bioremediation

“…Moreover, Beattie and Haverkamp [81] demonstrated that chloroplasts were the site of the most abundant reduction of Au 3+ salts to Au 0 nanoparticles in plants. This prompted the authors to investigate the possibility of biosynthesized gold nanoparticles using chloroplasts as biological templates and the chloroplasts acted in dual roles, ie as reducing agents and stabilizers in the course of the formation of gold nanoparticles [82].…”

“…Potentially toxic effects of nanoparticles on the environment and the organisms are not yet known, and probably there will be revealed in the coming years. There is a need to conduct much more research to understand the fate and transport of nanoparticles in the environment, meet their sustainability and toxicological effects on various biological systems, including humans [82,84].…”

Synthesis and characterization of surface-enhanced Raman-scattered gold nanoparticles

“…20 The subcellular organelle chloroplast reduced the Au salts to produce the GNPs. 21 GNPs with SERS signatures are used extensively in biomedical applications due to their inert biocompatible properties and high sensitivity in imaging application. 22 Localized SPR and SERS are due to the resonance of free electrons present in the GNPs.…”

“…21 Briefly, 1 g of GNPs was dissolved in 500 µL of rhodamine 6G (R6G; 20 µm) solution and incubated overnight. The doped GNPs were centrifuged and washed twice with water.…”

Ultra-pure, water-dispersed Au nanoparticles produced by femtosecond laser ablation and fragmentation

“…11 As an example, standard chemical procedure for the fabrication of colloidal Au nanoparticles is based on the reduction of a precursor salt with a reducing agent, which inevitably leads to surface contamination, mainly by residual anions and the reducing agent, complicating the above stated applications, especially in vivo. 12 The development of new methods for synthesizing plasmonic nanoparticles is an active field of research, 13,14 including fabrication by short laser pulses. 15,16 SERS applications are currently on the way to clinical trials, 17 and generic properties on nanomaterials in antiviral and cancer treatment applications are under fundamental study and in vivo experiments.…”