http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/39 Sun, 05 Apr 2026 04:51:09 GMT 2026-04-05T04:51:09Z http://http://starc.stthomas.ac.in:8080/xmlui:8080/xmlui/bitstream/id/f5bf5d63-1a25-437f-9648-6c9aa349e928/ http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/39 http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/97 Synthesis of silver and copper oxide nanoparticles using Myristica fragrans fruit extract: Antimicrobial and catalytic applications Sasidharan, Drishya; Namitha, TR; Johnson, Smera P; Jose, Vimala; Mathew, Paulson The pericarp of Myristica fragrans fruit extract was utilized for a low cost, eco-friendly synthesis of silver (AgNPs) and copper oxide (CuONPs) nanoparticles. The aqueous fruit extract of the plant was used as reducing and stabilizing agents for this preparation. Characterization of the biosynthesized nanoparticles was carried out using UV–Vis spectroscopy, FTIR spectroscopy and X-Ray Diffraction studies. Morphology and size of the particles was observed using Field-Emission Scanning Electron Microscopy (FESEM) and High Resolution Transmission Electron Microscopy (HRTEM). The copper and silver nanoparticles show Surface Plasmon Resonance (SPR) band at 360 and 478 nm respectively in the UV–Vis spectrum. It was observed that size of the synthesized copper oxide and silver nanoparticles are in the range 10–50 nm. The presence of copper and silver elements was confirmed from their respective EDS spectrum. Involvement of phytochemicals in the stabilization and reduction of the nanoparticles was confirmed by FTIR spectroscopy. CuONPs exhibited catalytic activity in 1,3-dipolar cycloaddition reaction between azides and terminal alkynes to form 1,2,3-triazoles. Silver nanoparticle possesses good antibacterial activity against multidrug human pathogens Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. The present study focuses on the utilization of the less economic part of Myristica fragrans fruit's pericarp for the preparation of copper oxide and silver nanoparticles which have good catalytic and antibacterial activities. Mon, 01 Jun 2020 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/97 2020-06-01T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/87 Photo-Mediated Facile Synthesis of Silver Nanoparticles Using Curcuma zanthorrhiza Rhizome Extract and Their In Vitro Antimicrobial and Anticancer Activity Aiswariya, KS; Jose, Vimala Plants possess unique bioactive principles justifying their multifunctional properties. In this work silver nanoparticles (AgNPs) were prepared via a photo-mediated green approach for enhanced antimicrobial and anticancer activity. The aqueous rhizome extract of Curcuma zanthorrhiza Roxb. (Cz) was employed as a source of reducing and capping agent for the synthesis of colloidal Cz-AgNPs. The materialization of Cz-AgNPs was identified from the surface plasmon resonance observed at 416 nm using UV–Visible spectrophotometer. The FTIR analysis of both Cz-AgNPs and plant rhizome extract revealed the as-synthesized Cz-AgNPs were capped with plant derived phytoconstituents. The crystallinity, surface morphology, hydrodynamic size and surface area of Cz-AgNPs were characterized by PXRD, HR-TEM, FESEM, DLS and BET analysis. The as-synthesized Cz-AgNPs exhibited strong antimicrobial activities against bacterial strains and plant pathogenic fungi in a dose-dependent manner. The antimicrobial activity of Cz-AgNPs was assessed using standard disc diffusion, broth microdilution assay for bacterial strains and poisoned food technique for fungal strains. The Cz-AgNPs were inhibitory to all the microbes even at the lowest concentration. The biocompatible nature of Cz-AgNPs was analyzed for hemolytic properties with human erythrocytes and promising results were observed. In addition, the cytotoxicity activity (Trypan Blue Exclusion Method) on the cell lines of Dalton’s Lymphoma Ascites (DLA) and Ehrlich Ascites Carcinoma (EAC) showed Cz-AgNPs exhibited potential anticancer activity with concentration as low as 1.67 µg/mL and 1.84 µg/mL respectively (IC50 value). This work attempted at optimizing a safe dosage of silver nanoparticles using hemolysis assay and thus for application in therapy. Sun, 21 Mar 2021 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/87 2021-03-21T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/83 Green synthesis of silver nanoparticles using Annona squamosa L. seed extract: characterization, photocatalytic and biological activity assay Jose, Vimala; Raphel, Lidiya; Aiswariya, KS; Mathew, Paulson The aqueous seed extract of Annona squamosa L. was used as a reducing and stabilizing agent for the synthesis of silver nanoparticles (AgNPs). The formation of AgNPs in aqueous silver nitrate solution after the addition of the extract was indicated by a colour change from pale yellow to dark brown corresponding to a λmax at 430 nm. The phytochemicals in the extract, responsible for efficient capping and stabilization of the nanoparticles, were identified by FTIR. Powder XRD pattern demonstrated the polycrystalline nature of the AgNPs. TEM image confirmed that AgNPs were spherical in shape and the average particle size was found to be 22 nm. Further, the nanoparticles exhibited good catalytic activity towards the degradation of coomassie brilliant blue dye and demonstrated significant antibacterial activity. Their larvicidal activity against mosquito larvae showed a LC50 value 22.44 μg/mL against III instars. In addition, AgNPs positively influenced the germination of chickpea seeds. Tue, 06 Apr 2021 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/83 2021-04-06T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/56 Bioactive Molecules Coated Silver Oxide Nanoparticle Synthesis from Curcuma zanthorrhiza and HR-LCMS Monitored Validation of Its Photocatalytic Potency Towards Malachite Green Degradation Aiswariya, KS; Jose, Vimala The study focuses on a non-stringent, rapid and sustainable way for the synthesis of silver oxide nanoparticles (Ag2ONPs) using aqueous rhizome extract of Curcuma zanthorrhiza Roxb. (Cz). High resolution liquid chromatography mass spectroscopy (HR-LCMS) was used for the simultaneous identification of bioactive molecules in the aqueous rhizome extract and its biosynthesized nanoparticles. The presence of eleven bioactive molecules in the rhizome extract acts as reducing and capping agents during the synthesis of Ag2ONPs. The molecules coated to Ag2ONPs were identified to be majorly sesquiterpenoids and lipid molecules. The analytical techniques used for the nanoparticle characterization included UV–Visible spectrum, which showed SPR band at 409 nm; FTIR spectrum depicted the bioactive molecules involved in capping and reduction of silver ions to silver oxide nanoparticles; XRD pattern attributed to fcc structure of CzAg2ONPs with an average size of 39.7 nm; HR-TEM and FESEM confirmed the size and morphology of CzAg2ONPs. The chemical nature of the bioactive molecules bound to Ag2ONPs revealed by HR-LCMS was in agreement with FTIR spectral data. The CzAg2ONPs exhibited efficient photocatalytic activity in the degradation of the toxic dye malachite green (MG) as revealed by the absorption spectra. The degraded product was subjected to HR-LCMS and found to be non-toxic. The results revealed the promising potential of bioactive molecules coated Ag2ONPs for environmental cleanup. Fri, 28 May 2021 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/56 2021-05-28T00:00:00Z