Keywords: gold nanoparticles, nanorods, composite materials, micropatterning, surface plasmons, nanotechnology, nanospheres, encryption, optical properties, patterns, encoding, decoding, polarised light, security
Patterning and encryption using gold nanoparticles
In this paper, we describe a simple technique for the creation of patterns on different size scales and in a variety of substrates, based on the selective reshaping of Au nanorods into nanospheres. The drastic change in the optical properties of these materials when their shape is modified provides a sensitive and accurate tool for the creation of areas with different colours. Additionally, because the nanorods possess orientation-dependent optical response, the patterns can be selectively encoded or decoded by using polarised light.