Biomedical Applications of Cocoa Bean-Extract Mediated Graphene Quantum Dots as Antimicrobial, Anticancer and Plant Growth Regulators

Abstract

A facile method has been developed for the first time for the synthesis of graphene quantum dots using The obroma cacao (cocoa seeds) by hydrothermal method. The structure and morphology of ensuring product was characterized by UV, FTIR, X-ray Diffraction (PXRD) and TEM and SAED pattern. Then anti-microbial, anti-oxidant and anti-cancer activities of T. cacao mediated graphene quantum dots were analyzed. Further investigations were made on the use of T. cacao mediated graphene quantum dots for growth enhancement in green gram (Vigna radiate). CSE-GQDs (Cocoa seed extract-Graphene quantum dots) showed greatest antimicrobial activity against the Staphylococcus aureus, Pseudomonas aeroginosa, Streptococcus mutans, Salmonella sp, Escherichia coli, Microsporum gypseum, Trichophyton sp. The results of antioxidant activity of the CSE- GQDs evaluated using DPPH scavenging assays indicates that the CSE- GQDs possess a higher scavenging activity. The cytotoxicity studies showed that the synthesized CSE- GQDs exhibited a dose dependent toxicity on human breast cancer (MCF-7) cell lines. The IC50 value for MCF-7 cells is found to be 31.2µg/ml of CSE- GQDs, where a 50% noticed cell death is observed. The germination rate of green gram seeds significantly increased after treatment with higher CSE-GQDs. Our investigations open up the opportunity to use graphene quantum dots as plant growth regulators that can be used in a variety of other food plants for high yield.