International Journal of Science, Engineering and TechnologyAuthors: Peter O. Adigun, Nnamso D. Ibuotenang, Solomon E. Shaibu
Abstract: This study reports the synthesis and comprehensive characterization of silver nanoparticles (AgNPs) with tunable optical properties, focusing on their localized surface plasmon resonance (LSPR) behavior and relevance to nanoscale light–matter interactions. AgNPs were synthesized via a modified Lee-Meisel method employing trisodium citrate as both a reducing and capping agent. Systematic variation in citrate volume enabled controlled modulation of nanoparticle size within the 10–40 nm range, as confirmed by Transmission Electron Microscopy (TEM). UV–Visible spectroscopy revealed distinct LSPR absorption peaks in the visible region. Photoluminescence (PL) analysis demonstrated enhanced emission for smaller nanoparticles, attributed to increased plasmon–exciton coupling and reduced non-radiative damping. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) validated surface morphology and elemental purity, respectively. Fourier Transform Infrared Spectroscopy (FTIR) identified functional groups such as hydroxyl and carboxylates, derived from citrate, which contributed to surface passivation and colloidal stabilization. X-ray Diffraction (XRD) confirmed the face-centered cubic (FCC) crystal structure of metallic silver with high crystallinity and phase purity. The combined results underscore the critical role of synthetic parameters in tailoring nanoparticle size, surface chemistry, and plasmonic response. This work establishes AgNPs as highly tunable platforms for integration into plasmon-enhanced technologies, with promising applications in biosensing, photothermal therapy, and nanophotonic systems.
DOI: https://doi.org/10.5281/zenodo.16870607
