Photo-Mediated Biological Preparation of Silver Nanoparticles Paste in an Organic Solvent System: Formulation and Antimicrobial Studies Publisher



S Hajihosseini S ; M Mozafar MARYAM ; N Torkashvand NARGES ; M Mollapoursisakht MAHSA ; Mh Yazdi Mohammad HOSSEIN ; S Minaiean S ; Ma Faramarzi Mohammad ALI ; N Samadi NASRIN ; Ar Shahverdi Ahmad REZA
Source: Applied Physics A: Materials Science and Processing Published:2025

Abstract

Silver nanoparticles (AgNPs) are recognized as promising nanomaterials with potent antimicrobial properties and a reduced risk of inducing resistance. In this study, we developed a semi-solid paste formulation by first preparing a thick aqueous colloid of AgNPs, intended for in situ application. Given the limitations of conventional aqueous colloids, particularly their instability during concentration via evaporation, we employed a biologically mediated method to synthesize AgNPs in organic solvent mixtures. Various additives and excipient cocktails were incorporated into the organic colloids to enhance stability and performance. All formulations were subsequently dried using conventional vacuum evaporation and re-dispersed in distilled water via ultrasonic treatment. The formulations were characterized using UV–Vis spectroscopy, and the optimal formulation was selected for further evaluation. The physicochemical and antimicrobial properties of the AgNP paste were analyzed using dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDS). The resulting aqueous colloid (1 mM) demonstrated excellent stability (zeta potential ~ − 37 mV) and contained nanoparticles ≤ 150 nm in size. This formulation (1mM) exhibited significant antimicrobial activity against all tested bacterial and fungal strains. © 2025 Elsevier B.V., All rights reserved.