Gold Nanoparticles Grown by Galvanic Replacement on Graphene-Coated Aluminum Panels as Large-Area Substrates for Surface-Enhanced Raman Scattering

Galvanic replacement (GR) is a widely used method to obtain substrates with nanostructure morphologies. However, there are substantial challenges related to the uniformity of the deposited nanostructures, the preparation of large-area nanocomposites, and the alteration of the morphologies deposited on substrates. Graphene was introduced into the surface of the aluminum panels in this study prior to conducting the GR reaction to incorporate graphene advantages of extremely high electrical conductivity and electron mobility. The experimental results revealed that the morphological consistency and particle densities of gold nanoparticles deposited on panels with graphene were much higher than those deposited on panels without graphene. Moreover, gold nanoparticles were deposited on the surfaces with graphene prior to deposition on those without graphene. Ordered large-area gold/graphene/aluminum hybrid nanocomposites can be obtained with desired morphologies by altering the preparation conditions. Finally, the feasibility of using the as-prepared gold hybrid nanocomposites as surface-enhanced Raman scattering (SERS) substrates was examined. The results indicated that the Raman signal enhancement factors of the as prepared substrates were varied as the preparation condition changed due to the difference in the morphologies. Under the optimal condition, a high enhancement factor of approximately 3 x 10(8) with good reproducibility was found, which demonstrates the potential of utilizing the as-prepared gold hybrid nanocomposites in SERS and other sensing applications.