Ultra-sensitive spectroscopy – with special emphasis on single molecule Surface Enhanced Raman Scattering – will continue to grow from the recent successes in the application of the technique to reveal new aspects of the physics of isolated molecules (especially those of biological interest) on surfaces. Among recent developments, our group has demonstrated the possibility of performing single-molecule electrochemistry, and revealed anharmonic interactions of single molecules on surfaces. This Objective will include applied pursuits of ultra-sensitive spectroscopy, like our recent development of a microscope to work in the so-called “Kretschmann configuration”. This instrument will allow us to detect minute changes of molecules deposited on gold substrates – as in surface-plasmon resonance (SPR) spectroscopy, but with the additional power of Raman spectroscopy. Recent publications relating to these latest developments can be found here.