Eco-Friendly Production of Silver Nanoparticles Using Starch and Assessment of Their Antioxidant and Antimicrobial Activities

Soluble starch was utilized to synthesize silver nanoparticles (AgNPs), serving as a green reducing and stabilizing agent. The biosynthesized AgNPs were subjected to comprehensive characterization using different analytical techniques. UV-visible spectroscopy revealed a characteristic surface plasmon resonance (SPR) peak at 415 nm, substantiating AgNP formation. X-ray diffraction (XRD) analysis confirmed the FCC crystalline structure of the silver. Transmission electron microscopy (TEM) revealed uniformly dispersed, spherical nanoparticles measuring 10–20 nm in size. Dynamic light scattering (DLS) measurements revealed a zeta potential of -10 mV, indicating moderate colloidal stability. Fourier-transform infrared (FTIR) spectroscopy verified that starch capped and stabilized the AgNPs, as shown by the presence of typical polysaccharide bands. The synthesized AgNPs displayed notable antibacterial effectiveness against multidrug-resistant pathogens, such as Acinetobacter baumannii (12 mm inhibition zone at 60 μg/mL) and Staphylococcus aureus (13 mm inhibition zone at the same concentration). Additionally, the AgNPs showed significant antioxidant activity that increased with dose, as determined by DPPH radical scavenging assays. These findings underscore the potential of using starch as cheap reducing and stabilizing of AgNPs for applications in antimicrobial therapy and as mild antioxidant agents. Schematic representation of the green synthesis of silver nanoparticles (AgNPs) using potato starch as a natural reducing and stabilizing agent. The process involves preparing a starch extract, mixing it with silver nitrate (AgNO 3 ) solution, followed by bioreduction of Ag + ions into Ag 0 nanoparticles. The formation of a reddish-brown color indicates the successful synthesis of silver nanoparticles, which are subsequently stabilized by starch molecules • Silver nanoparticles (AgNPs) were green-synthesized using soluble starch. • AgNPs showed a small size and high stability. • AgNPs exhibited notable antioxidant properties in DPPH and ABTS assays. • AgNPs demonstrated strong activity against drug-resistant S. aureus and A. baumannii. • AgNPs show antimicrobial and antioxidant agents for medical applications.