FORMULATION AND EVALUATION OF SILVER NANOPARTICLES FOR ANTIBACTERIAL ACTIVITY

Muskan Tomar*, Praveen Kumar

ABSTRACT

The present study focuses on the synthesis, characterization, and evaluation of silver nanoparticles (AgNPs) for their physicochemical properties and antibacterial activity. Silver nanoparticles were successfully prepared and subjected to comprehensive characterization using UV–Visible spectroscopy, viscosity analysis, pH measurement, dynamic light scattering (particle size and PDI), zeta potential analysis, transmission electron microscopy (TEM), refractive index determination, antibacterial assessment, and stability studies. UV–Visible spectroscopy confirmed nanoparticle formation with a characteristic surface plasmon resonance peak at 440 nm. The formulation exhibited suitable viscosity (18.6 ± 0.5 cP) and near-neutral pH (6.8 ± 0.2), indicating good stability and compatibility for biological applications. Particle size analysis revealed nanoscale dimensions (~21 nm) with moderate polydispersity, while zeta potential (−28.4 mV) indicated good colloidal stability. TEM analysis confirmed spherical to near-spherical morphology with uniform distribution in the range of 20–50 nm. The refractive index (1.36 ± 0.02) further supported the homogeneity and physical stability of the formulation. The antibacterial activity of silver nanoparticles demonstrated significant inhibition against Staphylococcus aureus (18.4 ± 0.6 mm) and Escherichia coli (20.1 ± 0.5 mm), indicating broad-spectrum antimicrobial potential. Stability studies showed minimal variation in particle size, PDI, and zeta potential over three months, confirming good formulation stability. Overall, the synthesized silver nanoparticles exhibited excellent physicochemical characteristics, strong antibacterial efficacy, and satisfactory stability, suggesting their potential application in pharmaceutical and biomedical fields, particularly as antimicrobial agents and in drug delivery systems.

Keywords: Silver nanoparticles, UV–Visible spectroscopy, particle size analysis, zeta potential, TEM, refractive index, antibacterial activity, stability studies, nanotechnology, antimicrobial agents.