On the Potential for Tuning the Longitudinal Plasmon Band of a Distribution of Gold Nanorods Using a Tunable Laser

Gold nanorods hold great potential for bio sensing, imaging and therapy applications. The seed-mediated approach is the most widely used technique for the synthesis of gold nanorods. However, batches of nanorods synthesized using this method have a broadened longitudinal plasmon (LP) peak and uncertainty in the wavelength of the peak. This paper describes a technique to tune the synthesized nanorod distributions by using laser pulses at specific wavelengths that either reduce the width of the population LP peak or control its position. The overlap between the LP peaks of pairs of batches of gold nanorods was successfully reduced by at least 9%. Batches of nanorods with a sharper LP peak and/or a more desirable LP resonance wavelength could eventually be utilized in molecular biosensing and imaging applications requiring the simultaneous detection and differentiation of multiple aspectratio gold nanorods.