2D nanostructure of gold nanoparticles: An approach to SERS-active substrate

Monolayer well-ordered close-packed 2D nanostructures of gold nanoparticles were fabricated without using any capping reagent or surfactant. The area of the 2D nanostructure obtained was as large as several 100 s μm2 to mm2. The individual gold nanoparticles of the 2D nanostructure are not in contact depicting the possible surface active site (i.e. hot site). The SERS-activity was measured by using crystal violet molecules adsorbed on the 2D nanostructure. The estimated enhancement was found as much as 108. Size-dependent SERS intensity of the well-ordered 2D nanostructures is discussed in detail.