Synthesis and Surface Functionalization of Silver Nanoparticles for Antimicrobial Coatings

Abstract

Silver nanoparticles are widely investigated for antimicrobial surface coatings, yet particle aggregation and inconsistent release kinetics continue to limit reproducible performance across coating substrates. This study reports a synthesis route combining controlled chemical reduction with post-synthesis surface functionalization using biocompatible ligands intended to improve particle dispersion stability and modulate silver ion release rate. Synthesized particles were characterized using electron microscopy, dynamic light scattering, and zeta potential measurements to assess size distribution, aggregation tendency, and surface charge stability across storage conditions. Antimicrobial performance was evaluated against representative gram-positive and gram-negative bacterial strains using standardized zone-of-inhibition and colony reduction assays applied to coated substrate samples. Results indicate that functionalized particles maintained more stable dispersion and more consistent antimicrobial activity over extended storage periods compared to unfunctionalized controls, with release kinetics following a more gradual and sustained profile. We discuss implications for coating durability in applications such as medical device surfaces and packaging materials, where consistent long-term antimicrobial performance is required. The findings support surface functionalization as a practical strategy for improving reproducibility in silver nanoparticle-based antimicrobial coating formulations intended for scaled manufacturing.