Chemical modification of graphene with grape seed extract: Its structural, optical and antimicrobial properties

Herein, we modified for the first time thermally reduced graphene oxide (TRG) using grape seed extract (GSE), by simple probe sonication method. The effect of GSE on the structural changes of TRG has been carefully analyzed through Fourier Transform Infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy and these spectral data proved that the TRG has been modified successfully. Furthermore, X-ray investigations proved the change in crystallinity and coherence length of TRG, which could be further, authenticated by Transmission electron microscopy (TEM). The optical properties of as prepared modified TRG (m-TRG) were investigated with the help of UV-Visible and photoluminescence spectroscopy. The band gap of m-TRG was found to be 4.1 eV and it exerted the luminescence in the visible region. Moreover, the antibacterial results showed that m-TRG has enhanced antibacterial activity and 80% of mortality was observed in both the gram positive and gram negative bacteria at a minimum concentration of 40 μg ml^-1 and 60 μg ml^-1. Thus, this m-TRG could find many applications in the future semiconductor and optoelectronic devices and it could be considered as a novel antibacterial agent that can find potential application in the areas of healthcare and engineering.