Origami Chips: paper-based Lab-on-a-Chip (LOC) devices for the rapid and cost-effective detection of drugs of abuse, including new psychoactive substances (NPS)

McNeill, Lauren Frances (2024) Origami Chips: paper-based Lab-on-a-Chip (LOC) devices for the rapid and cost-effective detection of drugs of abuse, including new psychoactive substances (NPS). Doctoral thesis (PhD), Manchester Metropolitan University.

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Abstract

New psychoactive substances and drugs of abuse are a major health risk globally. This research presents a simple, rapid, low-cost, and portable paper-based Lab-on-a-Chip (LOC) device for the selective multiplex detection of mephedrone (4-MMC; new psychoactive substance), its metabolite 4-methylephedrine (1-dihydromephedrone, 4-ME), and three commonly encountered drugs of abuse, amphetamine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). This LOC device has an ‘origami’ design that incorporates a competitive immunoassay using antibodies for the simultaneous multiplex detection of these controlled substances within three minutes at a cost of less than 50p per device. These controlled substances could be detected down to clinically relevant levels. Cross reactivity of commonly encountered ‘cutting agents’, were investigated and shown to have no effect on the detection capabilities. Twenty seized drug samples (provided by Greater Manchester Police via MANchester DRug Analysis and Knowledge Exchange, MANDRAKE) were tested using the optimised LOC device to determine the reliability, specificity, and reproducibility of the LOC device, with 95% specificity and 100% sensitivity. The LOC device was also evaluated by non-scientifically trained individuals with 100% specificity and 100% sensitivity. The results show that this LOC device can be used as a rapid and low-cost method to detect 4-MMC, 4-methylephedrine, amphetamine, methamphetamine and MDMA to clinically relevant levels. This portable device has the potential to provide on-site testing within forensic or clinical settings and therefore has wide global applicability.