Elucidating the chemical and biochemical applications of Citrus sinensis-mediated silver nanocrystal

Abstract

Synthesis of nanoparticles using biodegradable source is safer and echo-friendly. Here, we describe the synthesis of polycrystalline silver nanocrystals using Citrus sinensis acting as both reducing and capping agents. After exposing the silver ions to orange extract, rapid reduction of silver ions led to the formation of stable silver nanocrystals due to the reducing and stabilizing properties of orange fruit juice. The synthesized silver nanocrystals were characterized using various analytical techniques like UV–vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The biochemical activity of the synthesized nanocrystals was studied in the light of affinity to bovine serum albumin using several biophysical methods like absorbance, fluorescence and circular dichroism spectroscopy. Cytotoxic activity of these nanocrystals was also studied against Hep-2 cell line using fluorescence microscopy. It was also found that the synthesized nanocrystals can sense mercuric ion down to 50 µM in the presence of a number of cations. Furthermore, we established that the silver nanoparticles can effectively catalyse the reduction of methylene blue by ascorbic acid. The present study will enrich our knowledge on the chemical and biochemical activities of green-synthesized silver nanocrystals.

Keywords:

• Green synthesis
• silver nanocrystals
• orange extract (Citrus sinensis)
• protein binding
• antibacterial activity
• cytotoxicity study
• mercury sensing
• catalytic activity

Acknowledgements

N. Siddiqui acknowledges the Maulana Azad National Fellowship for a senior research fellowship. The authors would also like to thank Prof. P. Karmakar and Dr. D. Laha of Jadavpur University, Department of Life Science and Biotechnology, for various physical measurements.

Disclosure statement

There are no conflicts of interest to declare.

Additional information

Funding

M. M. Islam is grateful to the Department of Science and Technology, Govt. of West Bengal, for their financial support [Project No: 756 (Sanc.)/ST/P/S&T/9G-34/2013].