Enhancing sensing applications

October 2011

In sensing applications, where the light scattering from patterns of nanoparticles is the working principle, it is necessary to create strong light field enhancement – the ‘hot spots’- on a nanoscale at the locations where analyte molecules are present. The challenge is to increase the light field enhancement, which is limited by the ‘sharpness’ of the edges and corners of nanoparticles and is linked to fabrication resolution. However, by making chiral nanoparticles (having a property of handedness), it is possible to increase the amount of light enhancement per photon of light at the hot-spots. Furthermore, the light enhancement in the gaps can be controlled mechanically and thermally. This would augment sensitivity, allowing them to operate at lower light intensities and shortening measurement time.

This project aims to develop nanofabrication protocols for high-precision lithographic definition and fabrication of patterns of nanoparticles, whose light enhancement properties can be externally controlled by light polarisation, mechanically through gaps control on membranes, and surface waves, as well as by temperature. Fabrication of chiral nanoparticles with 10nm - 20nm gaps is still a challenging task to be solved in this project.

MCN provides the equipment necessary to realise new and challenging designs of nanoparticles for future sensing applications. Adding means-of-control at the nanoscale requires the use of advanced nanotechnology tools and protocols such as deposition, dry etching, and electron beam lithography.

During this project, scientific underpinnings of the novel sensing platforms will be established. The developed protocols and fabrication procedures will be transferable and most accessible to the local Victoria’s scientific community and businesses for future development. The benefits will be seen in health and security sectors where sensors are used.