Facile Preparation of Monodisperse Silver Nanorods with Tunable Plasmon Resonances in the Near-Infrared Region: Implications for SERS-Based Sensing

The facile synthesis of silver nanorods with uniform size and tunable localized surface plasmon resonances is of great significance for plasmon resonance-related applications, such as surface-enhanced Raman spectroscopy (SERS)-based sensing, biomedical diagnostics, and photothermal therapy. However, improving reproducibility is difficult for nonexpert researchers since general synthesis methods involve multiple steps. Addressing this issue, this work develops a facile, effective synthetic strategy for monodisperse silver nanorods with tunable plasmon resonance in the near-infrared region assisted by in situ monitoring via an optical microfiber in the seed formation stage and surfactant-assisted purification of the final product. The optical microfiber monitoring ensures the formation of monodisperse bipyramid templates, guaranteeing the synthesis of the final product. The surfactant-assisted purification of the final product ensures the monodispersity of the final Ag nanorods. This study provides a flexible and alternative approach for nonexpert researchers and may present an opportunity for solving the reproducibility problem faced by nanomaterial synthesis.