The design and preliminary characterization of a novel sensor for drugs of abuse, DETECHIP, is described in this proof-of-concept note. Combining both colorimetric and fluorimetric assays, DETECHIP is suitable for lab and field use. More than a conventional spot test which provides a single "yes or no" answer, DETECHIP provides twenty responses for a more complete characterization of suspect material. This is accomplished by visually noting colorimetric and fluorescent changes of carefully selected dyes upon the addition of test analytes, including drugs of abuse, with respect to controls. Color and fluorescence changes are recorded numerically so that a 20 digit identification code can be constructed for comparison of test analytes and known compounds. DETECHIP is applicable to a variety of drugs, both plant-derived and synthetic, addressing the need to use several different spot tests simultaneously for a single sample.

Using exciton-coupled circular dichroism (ECCD) spectroscopy, our lab was able to differentiate between the two enantiomers of methamphetamine using a commercially available porphyrin tweezer as an achiral host. The host-guest complex formed with (+)-(S)-methamphetamine produced a negative bisignate-shaped ECCD spectrum, whereas the complex formed with (-)-(R)-methamphetamine produced a positive one. This sensitive technique could serve as an alternative method for the enantiodiscrimination of chiral methamphetamine, a commonly abused drug in the United States.