We developed an optofluidic device containing a nanostructured substrate for surface enhanced Raman spectroscopy (SERS). The device is based on a silicon chip, on which structures were fabricated using electron lithography and wet etching to achieve a pattern of inverted pyramids on the surface, which was then covered by gold layer of defined thickness and roughness. The geometry of the surface allows localized plasmon oscillations to give rise to the SERS effect, in which the Raman spectral lines are intensified by the interaction of the plasmonic field with the electrons in the molecular bonds. The SERS substrate was enclosed in a microfluidic system from silicone polymer and glass, which allowed transport and precise mixing of fluids entering the chip, while preventing contamination or abrasion of the highly sensitive substrate. We used this device as a platform for quantitative detection of halogenated hydrocarbons such as 1,2,3-trichloropropane (TCP) in water in submillimolar concentrations. TCP is used in industry and it is a persistent environmental pollutant. The presented sensor allows fast and simple quantification of such molecules and it could contribute to environmental monitoring disciplines as well as enzymologic experiments with genetically engineered dehalogenases, which are potentially useful for bioremediation. This research is supported by Czech Science Foundation (CSF) 16-07965S, infrastructure was supported by MEYS (LO1212, LM2015055) and EC (CZ.1.05/2.1.00/01.0017).
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