The presence of the molecule responsible for cork taint can now be clearly identified, thanks to a recently developed sensor that can detect even the slightest traces of the most common wine fault. Further applications could include the identification of pesticides or even explosives according to NCCR Bio-Inspired Materials researchers at the University of Fribourg.

When a wine is “corked” it is usually the cork which releases the relevant molecules. These often come from fungicides the cork oak tree has been treated with. With the aid of a spongelike, porous supramolecular grid these ‘corked’ molecules can be “caught”. As soon as such a substance is present and has infiltrated the sensor’s pores, an optical marker becomes visible, in that the sensor ceases to fluoresce (gleam) and so indicates that the quality of the wine has been affected.

Detection of pesticides or explosives
The study also shows other applications: the sensor can detect particular pesticides or herbicides which are authorized in some countries but prohibited in Switzerland. Using the sensor would, for example, enable the detection of traces of these in fruit and vegetables. Moreover, the grid-like structure also reacts to explosives and could in future contribute to the detection of explosive substances at airports, for example. When testing, the sensor substance can either be used in solution (in the case of fruit juice or similar) or on a paper test strip. The sensor is able to be regenerated and is then ready to be reused in further tests.

International cooperation
The paper has just been published in the scientific journal “Inorganic Chemistry”. The study was undertaken under the direction of NCCR PI Prof. Katharina M. Fromm and PhD student Serhii Vasylevskyi at the University of Fribourg's Department of Chemistry. Some of the testing was carried out at the University of Bordeaux, France, under the supervision of Dr Dario Bassani of the Institute of Molecular Sciences. In addition, the research project was supported by the Swiss National Science Foundation.

Further information:
Link to the paper