Single Molecule Directivity Enhanced Raman Scattering using Nanoantennas

Single molecule detection by directivity enhanced Raman scattering is demonstrated using nanoantennas. Bianalyte Raman scattering is used to confirm the detection of single molecules of Rhodamine 6G and Nile Blue A in aqueous solution. Calculations show that Raman enhancement factors of 10(13) can be achieved by combined optimization of the local field enhancement (hotspot with 10(11) enhancement) and antenna directionality (with 10(2) enhancement).