Surface Enhanced Raman Scattering represents a promising technique to overcome the limitations of optical vibrational spectroscopy in terms of signal intensity and spatial resolution. Its potentialities as an ultrasensitive spectroscopy are particularly well expressed in the field of biophysics. In the last years, SERS-based platforms for molecular detection at ultra-low concentrations, sometimes integrated in microfluidic devices, have been developed achieving impressive results. Similarly, SERS-active nanosensors, specifically interacting with cells, have been developed for diagnostics, drug delivery and other biomedical applications. In the Conclusions, the main results of the Thesis are discussed and the perspectives of the work are addressed.