The present invention relates to a system for obtaining an optical spectrum 648 of analytes in a fluid sample, wherein a porous filter 602a, 602b is arranged so that the fluid sample may be placed onto a first region of the porous filter, and a SERS-active material 610a, 610b having a SERS-active surface is placed at least partially within the pores of the porous filter within a second region of the porous filter. The first region and the second region of the porous filter are spatially separated and connected by through-going pores so that only sufficiently small analytes are able to reach the second region. Thereby, the porous filter enables that the fluid sample is filtered so that only sufficiently small entities in the fluid sample reach the second region where they may be probed so that an optical spectrum related to the analytes in the filtered sample may be obtained. The optical system also comprises a light source 634, a light detector 642, and the optical analysis system is arranged for obtaining the optical spectrum 648 of the analytes adjacent to the SERS-active material 610a, 610b exclusively from the second region of the porous filter 602a, 602b.
|Country||International Bureau of the World Intellectual Property Organization (WIPO)|
|Publication status||Published - 2013|