Abstract
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•Synthesis of metallic nanostructures in presence and absence of oxygen.•Cudrania tricuspidata leaf extract as both a reductant and a stabilizer.•The physical morphology of synthesized AgNPs, AuNPs, Ag-AuBNPs were obtained.•The synthesized Ag-AuBNPs showed powerful broad spectrum antibacterial activity.•Presence of more DO enhances the production, morphology and biological applications.
Synthesis of Ag-Au mono and co-reduction of bimetallic nanostructures were prepared in the low or high dissolved oxygen (DO) in the reaction medium along with Cudrania tricuspidata leaves extract as both a reductant and a stabilizer. Mono reduction of Ag and Au nanoparticles (AgNPs, AuNPs) were obtained from AgNO3 and HAuCl4 in the low or high DO in the reaction medium along with green precursor, respectively. The same protocol for bimetallic synthesis Ag-Au core–shell nanostructures (Ag-Au BNPs) were prepared through blending both metal in single reaction medium. To detect Surface plasmon bands (SPR) band Ultra Violet–visible spectroscopy based wavelength was scanned for mono and bimetallic mixture, results reviles that AgNPs in the range 450 (low OD), 425 (high OD), AuNPs in the range 530 (low OD), 510 (high OD) nm were observed, also found in the Ag-Au core–shell nanostructures. The physical morphology of synthesized AgNPs, AuNPs, Ag-AuBNPs were obtained using UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) reveals the organic compounds in the plant materials, X-ray diffraction (XRD) analysis show the crystalline nature of AgNPS, high resolution transmission electron microscopy (HRTEM) with Selected area diffraction (SAED) pattern, EDS mapping, and energy dispersive spectroscopy (EDS). The synthesized Ag-AuBNPs showed powerful antibacterial activity towards a gram positive (Bacillus subtilis) and gram negative (Pseudomonas aeruginosa). Finally, presence of more Dissolve ODO enhances the production, morphology and biological applications.