Our environment is extensively polluted with plastic particles in a wide range of sizes, from the largest pieces that we can identify with our bare eyes, to the so called “microplastics” (< 5 mm). As a consequence of the improvement in detection techniques, we now know that, for example, up to trillions of microplastic particles per litre have been found in plastic bottles for infants and in general plastic-based consumer water containers. The risk that plastic micro-/nanoparticles might cause in humans is becoming clearer with the very recent detection of plastic in the human blood flow.
Plastic debris above the microplastic cut-off can be sampled easily (though tediously) using standard extraction, collection, and purification methods. However, microplastics are typically heavily underestimated when using such basic techniques. Additionally, the lower range of the microplastics size -the nanoplastic range- is practically invisible for the standard techniques currently available (Fourier-transform infrared and Raman spectrometry), which become unpractical for being time-consuming, non-automatable and therefore prone to bias.
In this project, we have made further steps to develop a technique that can deal with both issues: (1) chemical identification of micro-/nanoplastics beyond the current size detection limits using Surface Enhanced Raman Spectroscopy (SERS) and (2) provide a simple and original method to concentrate diluted solutions by solvent evaporation. The evaporation-driven concentration reduces the most tedious and time-consuming steps: the detection process, which can be easily automated in this way, solving potential bias that results when such search and/or scans are performed manually.
New regulations will soon be approved in the EU/EEA, which require better techniques for the detection and identification of micro- and nanoplastics in consumer products.
