title: Biomedical and Catalytic Applications of Gold and Silver-Gold Alloy Nanoparticles Biosynthesized Using Cell-Free Extract of Bacillus Safensis LAU 13: Antifungal, Dye Degradation, Anti-Coagulant and Thrombolytic Activities.
abstract: This study investigated the green biosynthesis of gold (Au) and silver-gold alloy (Ag-Au) nanoparticles using cell-free extract of Bacillus safensis LAU 13 strain (GenBank accession No: KJ461434). The biosynthesized AuNPs and Ag-AuNPs were characterized using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, and transmission electron microscopy. Evaluation of the antifungal activities, degradation of malachite green, anti-coagulation of blood, and thrombolysis of human blood clot by the biosynthesized nanoparticles were investigated. The AuNPs and Ag-AuNPs had maximum absorbance at 561 and 545 nm, respectively. The FTIR peaks at 3318, 2378, 2114, 1998, 1636, 1287, 446, 421 cm-1for AuNPs; and 3310, 2345, 2203, 2033, 1636, 1273, 502, 453, 424 cm-1for Ag-AuNPs indicated that proteins were the capping and stabilization molecules in the biosynthesized nanoparticles. The particles were fairly spherical in shape with size of 10-45 nm for AuNPs and 13-80 nm for Ag-AuNPs. Moreover, energy dispersive X-ray analysis of AuNPs revealed gold as the most prominent metal in the AuNPs solution, while silver and gold were the most prominent in the case of Ag-AuNPs. Selected area electron diffraction showed the biosynthesized nanoparticles as crystal structures with ring shape pattern. AuNPs and Ag-AuNPs displayed growth inhibitions of 66.67-90.78% against strains of Aspergillus fumigatus and A. niger at concentration of 200 μg/ml , and remarkable degradation (> 90%) of malachite green after 48 h. Furthermore, the nanoparticles prevented coagulation of blood, and also completely dissolved blood clots, indicating the biomedical potential of AuNPs and Ag-AuNPs in the management of blood coagulation disorders. This is the first report of the synthesis of AuNPs and Ag-AuNPs using a strain of B. safensis for biomedical and catalytic applications.
authors.forename: Sunday A
authors.initials: SA
authors.lastname: Ojo
authors.forename: Agbaje
authors.initials: A
authors.lastname: Lateef
authors.forename: Musibau A
authors.initials: MA
authors.lastname: Azeez
authors.forename: Suliat M
authors.initials: SM
authors.lastname: Oladejo
authors.forename: Abiola S
authors.initials: AS
authors.lastname: Akinwale
authors.forename: Tesleem B
authors.initials: TB
authors.lastname: Asafa
authors.forename: Taofeek A
authors.initials: TA
authors.lastname: Yekeen
authors.forename: Akeem
authors.initials: A
authors.lastname: Akinboro
authors.forename: Iyabo C
authors.initials: IC
authors.lastname: Oladipo
authors.forename: Evariste B
authors.initials: EB
authors.lastname: Gueguim-Kana
authors.forename: Lorika S
authors.initials: LS
authors.lastname: Beukes
mesh_terms: D000925:Anticoagulants / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001230:Aspergillus / Q000187:drug effects; D001407:Bacillus / Q000737:chemistry / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001709:Biotechnology; D002474:Cell-Free System; D004396:Coloring Agents / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006047:Gold Alloys / Q000737:chemistry*; D055772:Green Chemistry Technology; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D012834:Silver / Q000737:chemistry*
chemical_list: D000925:Anticoagulants; D000935:Antifungal Agents; D004396:Coloring Agents; D005343:Fibrinolytic Agents; D006047:Gold Alloys; D012834:Silver