Camellia sinensis mediated nanoparticles to control growth and biofilm in Vibrio sp

Abstract

Camellia sinensis renowned for its medicinal properties has been employed for centuries to address various ailments due to its anti-inflammatory, antioxidant, anti-cancer, and anti-diabetic properties. In this research, Camellia sinensis leaf extract was used for the eco-friendly and cost-effective synthesis of silver nanoparticles (CS-AgNPs). UV–Visible spectroscopy confirmed the synthesis of CS-AgNPs with a surface plasmon resonance band near 350 nm. Fourier-transform infrared (FTIR) analysis revealed functional groups such as alcohols, carboxylic acids, and amines, which acted as reducing, capping, and stabilising agents. Field-emission scanning electron microscopy (FESEM) showcased monodisperse, spherical nanoparticles ranging from 10 to 50 nm, while X-ray diffraction (XRD) confirmed their crystalline structure with prominent diffraction peaks at 38.24°, 44.42°, and 77.40°, corresponding to the (111), (200), and (311) planes of silver’s FCC structure. Zeta potential analysis demonstrated nanoparticle stability, revealing a negative surface charge of − 34.6 mV, which reduced agglomeration through electrostatic repulsion. Dynamic light scattering (DLS) analysis showed an average particle size of 148.6 nm, aligning with their suspension behaviour. Antimicrobial studies exhibited significant efficacy, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determined at 25 µg/mL and 50 µg/mL, respectively, in tested V. harveyi, V. parahaemolyticus, and V. alginolyticus. The tolerance level of 2 confirms the best bactericidal potential of CS-AgNPs. CS-AgNPs effectively inhibited the biofilm formation at their respective MIC. Comprehensive biochemical assays, including estimating the leakage of proteins, sugars, malondialdehyde (MDA) quantification, glutathione (GSH) measurement, and evaluation of superoxide dismutase (SOD) and catalase (CAT) activities, offered compelling evidence of CS-AgNPs’ robust antibacterial efficacy. This research underscores the transformative capacity of green tea extract, serving as a catalyst for eco-friendly, cost-effective, and reproducible silver nanoparticle synthesis. CS-AgNPs emerge as a potent and economically viable alternative to conventional antibiotics, poised to redefine therapeutic approaches in biomedical science and in aquafarming industries.