Peer Review #2 of "Biosynthesis of silver nanoparticles using Caesalpinia ferrea (Tul.) Martius extract: physicochemical characterization, antifungal activity and cytotoxicity (v0.1)"

Abstract

Background. Green synthesis is an ecological technique for the production of well characterized 45 metallic nanoparticles using plants. This study investigated the synthesis of silver nanoparticles (AgNPs) using a Caesalpinia ferrea seed extract as a reducing agent. Methods. The formation of AgNPs was identified by instrumental analysis, including ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), Xray diffraction (XRD) of the AgNPs, and surface-enhanced Raman scattering (SERS) spectra of rhodamine-6G (R6G). We studied the physicochemical characterization of AgNPs, evaluated them as an antifungal agent against Candida albicans, Candida kruzei, Candida glabrata and Candida guilliermondii, and estimated their minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values. Lastly, this study evaluated the cytotoxicity of the AgNPs in murine L929 fibroblasts cells using an MTT assay. Results. The UV-Vis spectroscopy, SERS, SEM, and XRD results confirmed the rapid formation of spheroidal 30-50-nm AgNPs. The MIC and MFC values indicated the antifungal potential of AgNPs against most of the fungi studied and high cell viability in murine L929 fibroblasts. In addition, this study demonstrated that C. ferrea seed extracts may be used for the green synthesis of AgNPs at room temperature for the treatment of candidiasis.