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Subject: Chemistry × Author: Moond, Monika × End date: 2022 × Start date: 2022 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Green synthesis of silver nanoparticles using leaf and seed extracts of Fenugreek (Trigonella foenum-graecum L.) for catalytic, antioxidant and antimicrobial activities
    (CCSHAU, Hisar, 2022-12) Moond, Monika; Sushila Singh
    The present study was undertaken for the synthesis of Fenugreek (Trigonella foenum-graecum L.) seeds and leaves extract mediated silver nanoparticles and evaluation of their antioxidant, antimicrobial and catalytic activities. Proximate composition and chemical parameters viz. moisture, ash, crude fat, crude fiber, crude protein, total carbohydrates, minerals (Fe, Cu, Zn, Mn), tannins and alkaloids were analyzed in seeds and leaves of Fenugreek. Phytochemical parameters viz. total phenolic content, total flavonoids, total sugars, reducing sugars and non-reducing sugars in seeds and leaves were extracted with three solvents namely aqueous, methanol and acetone. The aqueous extract of Fenugreek seeds and leaves contained adequate amount of phytochemicals which act as reducing, stabilizing and capping agent for Silver nanoparticles (AgNPs). Several physico-chemical parameters such as effect of extract amount, effect of AgNO3 concentration, effect of temperature, effect of pH, effect of reaction time were optimized for the efficent synthesis of silver naoparticles. Optimized conditions for biosynthesis were found as; reaction mixture containing seed extract (2mL) or leaves extract (0.2 mL) in 25 mL of 1mM AgNO3 solution at 45ÂșC temperature and neutral pH. Reaction mixture was incubated for 48 hrs for FS-AgNPs and 24 hours for FL-AgNPs in dark condition to ensure the compete reduction of Ag+ ions. Characterization of Biosynthesized nanoparticles was done using several techniques such as UV-Vis spectroscopy, Particle size analyzer (PSA), FESEM, EDX, HRTEM, SAED, FTIR and XRD to examine the size, shape and morphology of silver nanoparticles. Size of synthesized AgNPs were in the range of 10-60 nm, most of them were spherical shape, monodisperse and crystalline in nature having FCC lattice. Antioxidant activity (DPPH free radical scavenging activity), antimicrobial activity using agar well diffusion method against Staphylococcus auerus, Xanthomonas spp., Macrophomina phaseolina and Fusarium oxysporum were compared with crude plant extract. Biosynthesized AgNPs showed enhanced bilogical activity. AgNPs were found to have appreciable catalytic activity for the degradation of p-nitrophenol with rate constant 0.1075 min-1 and 0.1398 min-1 for FS-AgNPs and FL-AgNPs, respectively.