Cocaine by-product detection with metal oxide semiconductor sensor arrays

Paula Tarttelin Hernandez, Stephen Hailes, Ivan Parkin

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)
39 Downloads (Pure)


A range of n-type and p-type metal oxide semiconductor gas sensors based on SnO2 and Cr2O3 materials have been modified with zeolites H-ZSM-5, Na-A and H–Y to create a gas sensor array able to successfully detect a cocaine by-product, methyl benzoate, which is commonly targeted by detection dogs. Exposure to vapours was carried out with eleven sensors. Upon data analysis, four of these that offered promising qualities for detection were subsequently selected to understand whether machine learning methods would enable successful and accurate classification of gases. The capability of discrimination of the four sensor array was assessed against nine different vapours of interest; methyl benzoate, ethane, ethanol, nitrogen dioxide, ammonia, acetone, propane, butane, and toluene. When using the polykernel function (C = 200) in the Weka software – and just five seconds into the gas injection – the model was 94.1% accurate in successfully classifying the data. Although further work is necessary to bring the sensors to a standard of detection that is competitive with that of dogs, these results are very encouraging because they show the potential of metal oxide semiconductor sensors to rapidly detect a cocaine by-product in an inexpensive way.
Original languageEnglish
Pages (from-to)28464–28477
Number of pages14
JournalRSC Advances
Issue number47
Early online date4 Aug 2020
Publication statusPublished - 2020

Bibliographical note

This article is Open Access, Creative Commons BY license



ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)


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