tuning of gold nanorod plasmon through oxidative cyanide etching

• Published in: Physical chemistry chemical physics : PCCP 2016-06, Vol.18 (23), p.15619-15624
• Main Authors: Carattino, Aquiles, Khatua, Saumyakanti, Orrit, Michel
• Format: Article
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c6cp01679k

Single gold nanorods exhibit great opportunities for bio-sensing, enhanced spectroscopies and photothermal therapy. A key property of these particles is the surface plasmon resonance, that is strongly dependent on their shape. Methods for tuning this resonance after the synthesis of the particles are of great interest for many applications. In this work we show that, through very well known chemistry between gold atoms and cyanide ions, it is possible to tune the surface plasmon of single 25 × 50 nm rods by more than 100 nm towards longer wavelengths. This is achieved by slowly etching gold atoms from the surface of the particles, preserving their specific optical properties. Single gold nanorods exhibit great opportunities for bio-sensing, enhanced spectroscopies and photothermal therapy. We show how to red-shift the plasmon resonance of single nanorods controllably.