Fine Tuning of the Longitudinal Plasmon Resonance of Gold Nanorods by Depleting Gold Precursor

For gold nanorod synthesis, the seed-mediated growth as the most effective method has been used widely. However, the inevitable overgrowth leads to poor control of the final shape of particle. In present work, by adding chemical inhibitor to deplete the residual gold salt in solution, the growth process can be terminated effectively at any stage and nanorods with desirable shape can be produced. This kind of competitive precursor depletion provides a simple pathway to finely tune the wavelength of the longutidinal plasmon band of gold nanorods. It also has potential application in studying the crystallization mechanism of nonspherical metal nanoparticles in solution.