D2.1 Diatoms-based biosensor for bioplastic detection in water

Deliverable D2.1 reports the work performed by CUT in task 2.7. Using spectroscopic methods the research group at CUT, assisted by NTUA, realized spectra libraries for 7 diatom species as well as three different plastic typologies.The studies performed allow to identify, in 7 diatom species, spectroscopic characteristics that change when such organisms are in contact with water containing micro or nanoparticles generated by degrading plastic.The most relevant change is found in a specific fluorescent peak of chlorophyll a. Indeed, when plastic particles enter the diatom cell-body they interact with chlorophyll apparatus and, as result, the absorption spectra changes.This change can be easily detected by fluorescence spectrometry after only 4-8 hours of exposing diatoms to water containing plastic. Thus, diatoms coupled with simple light excitation and detection systems are excellent and fast biotic sensors able to estimate the presence of tiny materials generated by degrading plastic.It must be highlighted that the method developed by CUT is not quantitative, therefore only the presence of plastic micro- and nanomaterials can be identified in water. Finally, CUT also developed a second fluorescence spectroscopic method based on diatoms and ferrocyanide to determine the presence of plastic in water that enhances the detection capability of diatoms as well as lower the detection time to less than 4 hours.