Competence Center for Micro- and Nanotechnologies

In order to combine the advantages of fluorescence and surface enhanced Raman spectroscopy (SERS) using the same chip platform a nanostructured gold surface with a unique design allowing both the sensitive detection of fluorescence light together with the specific Raman fingerprint of the fluorescent molecules was established. This task requires the fabrication of plasmonic arrays permitting the binding of molecules of interest in different distances to the metallic surface. The most efficient SERS enhancement is reached for molecules directly adsorbed on the metallic surface due to the strong field enhancement, where however the fluorescence light is quenched most efficiently. Further, fluorescence can be enhanced efficiently by careful adjustment of the optical behavior of plasmonic arrays. Within this contribution the simultaneous application of SERS and fluorescence utilizing various gold nanostructured arrays are demonstrated by realizing a DNA detection scheme. The results shown open the way to more flexible use of plasmonic arrays in bioanalytics.