Development of multi-functional nanostructured membranes for airborne particles collection, fluidic sensing and co-localized plasmonic enhancement

The search for new methods enabling efficient collection of particulate matter and multifactorial analysis in terms of size distribution, elemental composition, and structural identification represents a key-aspect of current efforts in environmental science. In this thesis a significant part of the effort has been devoted to the problem of collection and concentration of airborne particulate matter on a miniaturised custom chip. For this purpose, I applied original nanofabrication approaches derived from nanotechnology to build a special Si3N4 sieve, capable of trapping the airborne micro- and nano-particles on the active region of custom modified free standing TEM membranes. In addition to this, by fabrication of nanophotonic structures on the active surface of chip concentrators, I studied the possibility to achieve co-localised and spatially resolved detection of submicrometric airborne particles, with high resolution and sensitivity. The results demonstrate that with the new prototype it is possible to investigate not only the concentration, size, and shape of collected particles, but also their chemical composition (via EDX spectroscopy) and molecular structure (via Raman spectroscopy).