Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application.

Entesar Ali Ganash,Reem Mohammad Altuwirqi

doi:10.3390/ma14092326

Abstract

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

Highlights

All glassware was washed with acetone and with distilled water to ensure that no contamination was present
One concerning the Origanum majorana extract solution, and another relating to silver nitrate (AgNO3 ) solution
The most important finding to emerge from the present work green synthesis of Ag NPs

Summary

Introduction

Researchers have shown increasing interest in using the PLAL method [1] This is attributed to the simplicity of the method and to the fact that it is a fast, one-step, ecofriendly green method [2]. It is beneficial in producing the desired size or shape of nanostructures by changing either the laser parameters, such as energy, wavelength, pulse width, and fluence, or the ablated material parameters, including bulk, powders, and solution [3]. PLAL assists in producing nanostructures of high purity, dispersibility, and stability [4] This has considerably opened up the field for the synthesis of various nanomaterials. This technique has been widely used to produce nanoparticles (NPs) of oxides [5], metals [6], and other materials [7]

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Results

Conclusion