Phytosynthesis of Ag@AgCl nanoparticles using two types of bionanotechnological protocols exhibiting unique antimicrobial, antioxidant, and anti-inflammatory properties

Introduction The synthesis of nanomaterials aims to integrate scientific innovation with a commitment to address the UN’s Sustainable Development Goals (SDGs). Our study reports two biotechnological protocols for the synthesis of colloidal Ag@ AgCl nanoparticles (Ag@AgCl-NPs) using the endemic Mauritian herb Psiadia terebinthina via microwave extraction (ME) and heat extraction (HE) methods. Methods The Ag-based nanoparticles (NPs) containing colloids and extracts were tested for antimicrobial, antioxidant, and anti-inflammatory activities. The successful bottom-up phytosynthesis of Ag@AgCl-NPs was characterized by transmission electron microscopy (TEM) with chemical verification using energy-dispersive X-ray spectroscopy (EDS), crystallinity assessment using X-ray diffraction (XRD), UV–VIS and Fourier transform-infrared (FT-IR) spectroscopy, and investigation of colloidal properties. Green synthesis approaches favored NP formation and colloidal stability. Antimicrobial activity was tested against Gram-positive (G+) and Gram-negative (G−) bacteria and fungi using the broth microdilution assay. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, while anti-inflammatory activity was examined using the bovine serum albumin (BSA) test. Results Our results confirmed the successful green bionanotechnological synthesis of Ag@AgCl-NPs with varying relative mass ratios, exhibiting spherical morphology and good crystallinity. Additionally, both colloids with Ag@AgCl-NPs exhibited exceptional synergistic antimicrobial effects against highly resistant G+ and G− bacterial pathogens and the yeast Candida albicans . They also demonstrated significant anti-inflammatory activity compared to ME or HE extracts, which, surprisingly, showed greater antioxidant activity. Discussion Thus, eco-friendly phytosynthesis from Psiadia terebinthina extracts yielded multifunctional hybrid products with potential utility in pharmacology, medicine, and toxicology.