Pesticides measured at the riverbank: SERS in a microfluidic channel
The STARDUST consortium, with the Institute of Physical Chemistry of the Polish Academy of Sciences among its partners, is building a portable optical sensor detecting several pesticides at once in surface and ground water.
- The set-up combines surface-enhanced Raman spectroscopy (SERS) with microfluidics: the sample flows through a transparent channel a fraction of a millimetre across and the signal is read on the fly.
- SERS amplifies the signal of molecules settled on a metal nanostructure and pushes the detection limit down to where plain Raman sees nothing.
- Untangling overlapping spectra is left to spectral data analysis with machine learning — without it, measuring many pesticides at once would make no sense.
- The target is a device the size of a cabin suitcase, carried to a river, an intake or a lake; the measurement happens on a chip the size of a fingernail.
- The consortium: SINTEF MiNaLab (Norway), INCDFM and IMT (Romania), the Institute of Physical Chemistry PAS (Poland), DCU (Ireland), DTU (Denmark). In Denmark and Ireland volunteers collect samples after heavy rainfall.
- A field reading will not replace a report from an accredited test, but it tells you when and where to take the sample: after a downpour concentrations move faster than any sampling schedule.
Source: SINTEF