Efficacy of mycosynthesised AgNPs from Earliella scabrosa as an in vitro antibacterial and wound healing agent

The silver nanoparticles (AgNPs) with their unique chemical and physical properties are proving as a new therapeutical agent. In the present study, the AgNPs synthesised from an aqueous extract of a macrofungus, Earliella scabrosa, were characterised by field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and further evaluate for its in vitro antibacterial and wound healing efficacy. The mycosynthesised AgNPs exhibited the surface plasmon resonance peak at 410 nm with good stability over a period of a month. The FESEM and EDX analyses revealed the spherical-shaped AgNPs of an average size of 20 nm and the presence of elemental Ag, respectively. The XRD pattern showed the crystalline nature of AgNPs. The FTIR spectra confirmed the conversion of Ag+ ions to AgNPs due to reduction by biomolecules of macrofungus extract. The mycosynthesised AgNPs showed effective antibacterial activity against two Gram-positive bacteria, namely Bacillus subtilis and Staphylococcus aureus, and two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. The pathogens were highly sensitive to AgNPs, whereas less sensitive to AgNO3. The mycosynthesised AgNPs showed significant wound healing potential with 68.58% of wound closure.

Role of Ribes khorassanicum in the biosynthesis of AgNPs and their antibacterial properties

Silver nanoparticles (AgNPs) have been biosynthesised through the extracts of Ribes khorassanicum fruits, which served as the reducing agents and capping agents. Biosynthesised AgNPs have been found to be ultraviolet-visible (UV-vis) absorption spectra since they have displayed one surface plasmon resonance peak at 438 nm, attesting the formation of spherical NPs. These particles have been characterised by UV-vis, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy analysis. The formation of AgNPs at 1.0 mM concentration of AgNO3 has resulted in NPs that contained mean diameters in a range of 20-40 nm. The green-synthesised AgNPs have demonstrated high antibacterial effect against pathogenic bacteria (i.e. Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa). Biosynthesising metal NPs through plant extracts can serve as the facile and eco-friendly alternative for chemical and/or physical methods that are utilised for large-scale nanometal fabrication in various medical and industrial applications.

NanoUV-VIS: An Interactive Visualization Tool for Monitoring the Evolution of Optical Properties of Nanoparticles Throughout Synthesis Reactions

Engineered nanoparticles (NPs) are being used for a broad array of high technology applications including sensing, imaging, targeted drug delivery, bio-diagnostics, catalysis, optoelectronics and film growth seeding. The enhanced optical, electrical and catalytic properties of metal NPs are strongly correlated with their size, shape, and structure. As such, physicochemical characterization of NPs is critically important to ensure their effective use and applicability. In this context, Ultraviolet/Visible Spectroscopy (UV/VIS) is one of the most widely used methods for measuring the optical properties and electronic structures of NPs. UV/VIS absorption bands are related to important properties such as the diameter, shape, and polydispersity of metallic and semi- conducting NPs. Thus, this analytical technique is used during NP synthesis to monitor NP formation, assess suspension stability under different conditions and media, and to establish the optical properties of the newly formed nanomaterials. In view of the extensive use of UV/VIS for NP characterization and monitoring of NP formation during synthesis reactions, we have developed NanoUV-VIS, an interactive web application designed for the analysis of multiple UV-VIS absorbance spectra measured as a function of time. Graphical visualizations of the data in 2 dimensions (spectrum plot, contour plot) and 3 dimensions (surface plot) are created by this tool. In addition, the NanoUV-VIS tool evaluates and estimates important parameters related to the absorption bands of NPs, including, maximum optical absorbance, Surface Plasmon Resonance (SPR) peak and the Full Width at Half Maximum (FWHM) of the UV/VIS spectra. This information is available to download as a table in the software, as well as in the form of interactive plots, where the scientist can compare the behavior of these parameters in order to better interpret the outcomes of the experiment.