A portable, inexpensive sensor capable of detecting the presence of chemical pollutants (PFAS) in water in just a few minutes. This is the result of a study coordinated by Marcello Berto of the University of Modena and Reggio Emilia (UniMoRe), in collaboration with Pierangelo Metrangolo of the Polytechnic University of Milan (PoliMi) and Lucia Pasquato of the University of Trieste (UniTS). The research has just been published in the journal Advanced Functional Materials and is part of the PRIN-Nifty project funded by the Italian Ministry of Universities and Research (MUR).

PFAS, poly- and perfluorinated alkyl substances, are chemical compounds used in numerous consumer products, from non-stick pans to waterproof fabrics. Resistant to degradation, they accumulate in living tissues and spread into the environment – water, soil and air – even over long distances, making them one of the most insidious pollutants for health today.

The sensor developed by the three universities responds to this need: it is based on an organic electrolyte modulation transistor, capable of distinguishing different types of PFAS thanks to a special molecular coating designed by the UniTS research group.

'The heart of the sensor,' explains Lucia Pasquato, professor of organic chemistry at the Department of Chemical and Pharmaceutical Sciences, 'is a gold electrode coated with a mixed self-assembled monolayer (SAM) consisting of two types of molecules. Our group has been working on these coatings for over 15 years, particularly those containing fluorinated molecules, and we have developed the expertise to design them in such a way as to make them stable, reproducible and effective. In this case, the aim was to create a SAM that would bring the water to be analysed into contact with the electrode and at the same time be able to interact with PFAS. To do this, we combined two components: fluorinated thiols, which promote the recognition of contaminants thanks to fluorine-fluorine interactions, and hydrophilic thiols, which improve the wettability of the surface. This combination, together with the expertise of the UniMoRe and PoliMi groups, has resulted in a portable, inexpensive and high-performance sensor.’ 

The full article on Advanced Functional Materials