Directed growth of metal nanoparticles on substrates by polarized light irradiation

Sensitivity of optical sensing can be enhanced using assistance of plasmon generated at metal nanostructures, like SERS-based sensing. The growth process of metal nanoparticles which can control both shape and orientation on substrates in one step is required to solve the problem of the arrangement of pre-synthesized metal nanorods or other nanostructures to the surface of substrates in specific orientation. In this study, the procedure of polarized-light-directed growth of metal nanoparticles fixed on glass substrates in direct way is proposed, in which the irradiation of linearly polarized light to pre-deposited gold seeds on substrate, in immersing the substrates in the growth solution containing metal cations (gold or silver ions) and reducing agents. Consequently the anisotropic nanostructures whose orientation angle was in accordance with polarization direction in growth process were obtained. The evaluation of the resulted structures was performed with UV-vis spectrometer and scanning electron microscope.