Green Chemistry-induced carbon nanoparticles with antioxidant and antibacterial assay

Abstract

Carbon nanoparticles (CNPs) are among the most extensively researched and utilized nanomaterials due to a combination of unique optical and electronic properties. This work proposes an inexpensive and time-efficient green synthesis method for synthesizing fluorescent CNPs from the leaf extracts of Murraya koenigii, following a microwave-assisted approach. This work highlights the successful synthesis of CNPs using a single organic solvent throughout the procedure, without the use of any hazardous chemicals. They offer great dispersibility with water, ranging from 20-30 nm in size, as confirmed by scanning electron microscopy (SEM), with the maximum height observed at 1.92 nm, as confirmed by atomic force microscopy (AFM). The derived CNPs exhibited bright red fluorescence emission at 663 nm, as investigated by optical characterization. The chemical functional groups were investigated and interpreted using Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy. Further, the antioxidant assay was performed on derived CNPs with different concentrations, which exhibited excellent free radical scavenging properties. Moreover, the anti-bacterial activity was performed with E. coli and S. aureus, along with antioxidant assay. This work demonstrates a non-toxic and straightforward approach to promoting sustainable development by synthesizing CNPs using green leaf extracts. Nanoparticles possessing bright red fluorescence in the near-infrared (NIR) region opens up further scope of this work to contribute towards biomedical and plant health applications such as bioimaging, drug delivery, lateral root growth tests, and therapeutics.