Cobweb as novel biomaterial for the green and eco-friendly synthesis of silver nanoparticles

Abstract

In this study, spider cobweb as a novel biomaterial was used for the green synthesis of silver nanoparticles (AgNPs). The synthesized AgNPs were characterized using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy. The efficacy of biosynthesized particles as antibacterial agents was evaluated using multidrug resistant clinical bacterial isolates through sensitivity testing with AgNPs and combination of AgNPs with some selected antibiotics. In addition, the potential application of the particles as additives in paints was demonstrated using some bacterial and fungal isolates. The synthesized AgNPs which were dark brown in color displayed maximum absorbance at the wavelength of 436 nm. It was observed that the reaction mixture of 1:40 (extract:AgNO 3 solution) at pH of 8.5 produced particles with maximum absorbance at 436 nm. The FTIR spectrum showed peaks at 3298, 2359, 2089, and 1635 cm -1 , indicating that proteins were the capping and stabilization molecules in the synthesis of AgNPs. The particles were spherical in shape with size ranging about 3-50 nm. The energy-dispersive X-ray analysis showed the presence of silver as the most prominent metal, while the selected area electron diffraction pattern conformed to the face-centered cubic phase and crystalline nature of AgNPs. The AgNPs inhibited the growth of several bacterial isolates including S. aureus, E. coli, Klebsiella granulomatis and P. aeruginosa in the range of 10-17 mm at concentration of 100 lg/ml. It was also demonstrated that AgNPs potentiated the activities of augmentin, ofloxacin and cefixime in the AgNP-antibiotic synergy studies. Similarly, the inclusion of AgNPs as additive in white emulsion paint led to the total inhibition of growth of E. coli, P. aeruginosa, Aspergillus niger and A. fumigatus. To the best of our knowledge, this is the first report of the use of cobweb for the green synthesis of AgNPs. The immense antimicrobial activities of the particles can be explored in the creation of novel products, where it can be used as additive to protect materials against microbial attack.

Novel biosynthesized silver nanoparticles from cobweb as adsorbent for Rhodamine B: equilibrium isotherm, kinetic and thermodynamic studies

“…AgNPs used in this study were biologically synthesized from cobweb as earlier described (Lateef et al 2016f). The scheme of the synthesis is shown in Fig.…”

“…Biosynthesis was carried by reacting 1 ml of cobweb extract with 40 ml of AgNO 3 under ambient condition. The biosynthesized AgNPs were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) as previously described by Lateef et al (2016f).…”

“…Earlier data revealed that cobweb extract-mediated AgNP biosynthesis gave dark brown nearly spherical crystalline AgNPs with surface plasmon resonance obtained at 436 nm. The polydispersed particles having size range of 3-50 nm were formed due to the activities of proteinous materials in the cobweb extract (Lateef et al 2016f). The AgNPs mediated by cobweb extract have shown…”

“…tremendous activities; including antimicrobial (Lateef et al 2016f), desulphurization (Olajire et al 2017), hydrogen peroxide scavenging, anticoagulant and thrombolytic applications ). However, until now, there is no report on the use of cobweb-mediated AgNPs for the removal of dyes.…”

Cola nitida-Mediated Biogenic Synthesis of Silver Nanoparticles Using Seed and Seed Shell Extracts and Evaluation of Antibacterial Activities

“…This was the first report of its isolation in Nigeria and demonstration of the capacity of the bacterium to produce keratinase. More recently, the novel utilization of spider cobweb for the green synthesis of silver nanoparticles (AgNPs) was first reported in our laboratory [4].…”