It would be beneficial to detect amphetamine-type stimulants (ATS) and precursors not only in a forensic lab, but also via field sensors. These would be used by customs and law enforcement units in their daily fight against the trafficking and street distribution of illicit drugs. Such sensors would need to combine hand-portability, high sensitivity, fast response, low false alarm rates, and robustness, together with the ability to analyze substances with a range of different chemo-physical characteristics, and to establish chemical similarities ...