New Aspects in Surface Plasmon Fluorescence Spectrocospy

Based on surface plasmon fluorescence spectroscopy, §this work concerns the development of very high §sensitive optical biosensors. Two main aspects were §studied to achieve this purpose. The first part was §concerning grating couplers as biosensors; where the §effect of the distance between the chromophore and §the metal layer was studied, using protein layer by §layer system. The second part of this work was a §systematic investigation of long-range surface §plasmons. For the first time, LRSPR was used in a §fluorescence spectroscopic mood. The idea was using §the high field intensity at the interface, which is §higher in case of LRSPR than in the conventional §SPR, to excite the chromophores. We found that the §fluorescence signal in this case is about 9 times §higher, which give this system the ability to be §used as a very high sensitive device for detection §of small molecules with low concentrations. The most §important aspect about LRSPFS, beside the high field §intensity, is the very long evanescent filed that §can reach 400-800 nm, this can allow detection of §long biological matrix, big molecules, or even §studying live cells.