Biosynthesis of gold nanoparticles using aqueous extract of Ricinus cummunis leaves to augment catalytic degradation of organic dyes and study of its antifungal and antibacterial activities

In this study,biosynthesis of gold nanoparticles(Au NPs)using aqueous extract of fresh leaves of Ricinus cummunis plant is reported without the use of any synthetic chemical in the reaction process.The prepared NPs are mostly spherical in shape with some particles having triangular or hexagonal struc-tures.The average size of the particles as calculated using TEM data is 18 nm.The biosynthesised Au NPs were studied for their application in remediation of Congo Red,Methylene Blue,Reactive Red 120 and Rhodamine B dyes present in industrial effluents.The degradation of dyes was confirmed spectropho-tometrically using UV-Vis Spectrophotometer.Reactive Red 120 and Congo red dyes were most effec-tively reduced with 88%degradation.The Au NPs were further studied for their potential as an effective antifungal agent against fungal strains namely Candida albicans and Aspergillus fumigatus and antibac-terial properties against Bacillus subtilis(Gram+ve)and Pseudomonas aeruginosa(Gram-ve)bacterial strains.The MIC values being 7.8 and 15.6(μg/mL)for Bacillus subtilis and Pseudomonas aeruginosa respectively.