In the present invention, a molecular analysis device comprises a substrate, and a waveguide with a planar integrating element and filter or reflector element adjacent thereto is disposed on the substrate. The waveguide comprises a coupling means configured for coupling a predetermined frequency range of laser radiation into the waveguide. At least one metallic nanostructure is disposed on or adjacent to the planar integrating element, at least one metallic nanostructure is configured such that the field intensity and the gradient of the laser radiation, that is coupled into the waveguide, are enhanced over a sufficiently large volume around the nanostructure to simultaneously cause plasmonic based optical trapping of analyte(s) in a medium, and plasmonic based excitation of the particles to produce Raman scattered radiation. A Raman scattered radiation collection means is disposed on the substrate for collecting said Raman scattered radiation produced by the particles.