Bioplasmonics and Scanning Probe Microscopy

Plasmonics, i.e. the occurrence of plasmon resonances on metallic nanometer-scale structures, is an intrinsically nanoscale phenomenon, given that the two resonance conditions (i.e., negative dielectric permittivity and large free-space wavelength in comparison with system dimensions) are realized at the same time on the nanoscale. Resonances on surface metallic nanostructures are often experimentally found by probing the structures under investigation with radiation of various frequencies following a trial-and-error method. A general technique for the tuning of these resonances is highly desirable. Plasmonics nanostructures play a fundamental role in Raman spectroscopy, due to the enhancement of local electromagnetic fields. Analogously, Scanning Probe Microscopy (SPM) can detect and manipulate matter on nanoscale giving a fundamental tool to tune plasmon resonance. The basic purpose of the activity is the combination of plasmonics with SPM and its application to biological systems, with a special interest to oncology. Raman spectroscopy and gold nanoparticles have been applied to detect i) the changes between osteoblasts osteosarcoma cells, and ii) degree of malignancy of chondrosarcoma tissues. In turn, another objective of our activity is the development of a Tip Enhanced Raman Scattering device to study the Raman spectroscopy to nanoscale areas.

Members:
Patrizia Cioni
Mario D'acunto (Principal investigator)