Abstract
[Display omitted]
•Microwave-irradiated bio-fabrication of Ag-NCs polycrystalline phases using BCE.•Formation of polycrystalline Ag/AgO/AgCl with a maximum crystallite size ∼37 nm.•SEM and HR-TEM micrograph revealed a spherical/oval shape with a size of ∼50 nm.•SERS and SAED pattern confirmed polycrystalline Ag-NCs according to XRD.•Zone of inhibition and MIC showed adequate antibacterial and antifungal properties.
The rapid emergence of multidrug-resistant microbes has turned into the main threat to public health worldwide. The preparation and application of nanomaterial-based antimicrobials have increased to address this problem with great significance. This study has investigated the bio-fabrication of polycrystalline Ag-NCs using BCE as a reducer and stabilizer under microwave irradiation. Ag-NCs formations were optimized using varying concentrations of BCE and silver acetate. The XRD confirmed the incidence of phases of nanostructured crystals of Ag/AgO/AgCl. The average crystallite sizes were calculated to be 22.19, 36.65, and 36.65 nm for Ag, AgO, and AgCl, respectively. SERS spectra revealed the vibrational modes of the Ag and Ag-O stretch bands. FTIR spectra have indicated the incidence of chemical fingerprints for Ag-NCs and BCE biomolecules. SEM and HR-TEM micrographs exhibited the almost spherical to the oval shape of ∼50 nm. SAED pattern attested to silver crystallinity in agreement with XRD analysis. The MIC values of the Ag-NCs against Escherichia coli, Staphylococcus aureus, Aspergillus brasiliensis, and Rhizopus stolonifer were observed to be 120, 60, 200, and 100 µg/ml, respectively. This study has demonstrated the facile method to prepare polycrystalline Ag-NCs with appropriate structural and morphological characteristics for antimicrobial applications.