Silver or gold deposition onto magnetite nanoparticles by using plant extracts as reducing and stabilizing agents

Abstract

In this paper, we describe an environmentally friendly procedure to produce silver (Ag) or gold (Au)-deposited magnetite nanoparticles by using plant extracts (Ligustrum vulgare) as reducing and stabilizing agents. Firstly, magnetite nanoparticles (∼6 nm) with superparamagnetic properties – SPIONs – were synthesized by co-precipitation of Fe^{+ 2} and Fe^{+ 3} ions. Color changes indicated the differing amounts of Au and Ag ions reduced and deposited on to the SPIONs when the plant extracts were used. UV-vis and transmission electron microscope (TEM) with energy dispersive X-ray (EDX) apparatus confirmed the metallic deposition. Magnetic saturation decreased when the amount of the metallic deposition increased, which was measured by vibrating sample magnetometry (VSM). Due to the molecules coming into contact with – and even remaining on – the surface of the nanoparticles after aggressive washing procedures, the Ag/Au-deposited SPIONs were stable, and almost no agglomeration was observed for months. Fourier Transform Infrared (FTIR) spectra depicted that functional groups such as carboxylic and ketone groups, which are most probably responsible for the reduction and stabilization of Ag/Au- carrying magnetite nanoparticles, originated from the plant extract. The proposed route was facile, viable, and reproducible, and it should be stressed that nanoparticles do contain only safe biomolecules as stabilizing agents on their surfaces.

Keywords::

• green synthesis
• Ligustrum vulgare plant extract
• superparamagnetic iron oxide nanoparticles
• tunable gold and silver deposition

Acknowledgements

MY is supported by a TUBITAK BIDEB fellowship. EP also acknowledges support from the Turkish Academy of Science as a full member. This study was supported by the TUBITAK-1003 program (Project Number: 1130864) and also by the EU-FP7-IAPP Project: NanobacterphageSERS.

Declaration of Interest

The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.