Controlling the absorption region of multi-shaped silver nanoparticles for SERS applications

Introduction: Silver nanoparticles (Ag NPs) are pivotal in advancing surface-enhanced Raman scattering (SERS) due to their exceptional plasmonic properties. Yet, conventional synthesis methods often fail to precisely control their shape and size, impacting SERS efficiency. This study introduces a novel synthesis approach using hydrogen peroxide (H2O2) to tailor Ag NP morphologies, aiming to optimize their plasmonic resonance for improved SERS detection of hazardous substances. Methods: We utilized a chemical reduction process with H2O2 to etch and shape Ag NPs, adjusting H2O2 concentrations to control nanoparticle morphology. The characterization of the nanoparticles involved SEM, TEM, and XRD for morphology and structure, with UV-Vis spectroscopy determining their absorption spectra. Results: The approach yielded Ag NPs with variable shapes and absorption wavelengths (330 nm to 740 nm), directly correlating H2O2 concentration with morphological changes. SEM and TEM showed diverse nanoparticle shapes, and XRD confirmed their crystalline structure. Notably, nanoparticles tuned to specific absorption wavelengths significantly enhanced SERS detection of Rhodamine B. Conclusion: Our method effectively produces multi-shaped Ag NPs with tunable optical properties, enhancing SERS application in detecting trace organic compounds. This streamlined synthesis process offers new possibilities for environmental monitoring and safety assessments.