Evaluation and validation of a non-invasive (using fingerprints) drug screening device as a point-of-care tool for the detection of illicit drugs

Studies have indicated that substance misuse is associated with poor prognosis and treatment outcome. However, clinicians' often underestimate the presence of substance misuse problems when assessing patients with psychiatric and psychological disorders. It is not unusual for those working with patients who have these conditions to assume that signs of substance use are due to transient physical problems, or the disorder itself. A simple biological tool to assist the clinician in the identification of illicit substances has yet to be identified. There have been calls for a non invasive drug testing device for use in settings where substance misuse may not be the primary diagnosis. It is important that health care and other professionals who suspect substance misuse are able to confirm use in order to discover to improve the treatment outcome and learn more about the drivers for such behaviour.We propose a study to evaluate the utility of deposited fingerprints as a novel, non invasive method for drug testing that has the potential for application in a wide variety of settings. Laboratory testing for substance misuse relies extensively on the ability to detect or measure a range of psychoactive substances and their metabolites in body fluids or tissues (biomarker). One of the major challenges for testing procedures is the wide array of psychoactive substances that may be consumed and the need for specific approaches for them. A drug may be detected in any body fluid or tissue but there are practical limitations that govern which samples can be, and are, used. The choice of biomarker is influenced by the pharmacokinetics of the substance being tested for, and the ease with which it can be analysed in a laboratory setting. This research proposal aims to explore the feasibility of using deposited fingerprints as a screening instrument to detect drugs of abuse in clinical settings such as drug treatment agencies and mental health services. There is already a considerable body of evidence to show that drugs and their metabolites can be detected in human sweat. Studies have successfully indentified cocaine and metabolites [Huestis 1999, Kidwell 2003;Cone 1994; Winhusen 2003, Samyn 2002]; opiates [Cone 1994, Kintz 1997, Samyn 2002]; amphetamines [Samyn 2002];
benzodiazepines [Kintz 1996] and methadone [Skopp 1996, Henderson 1973]. This proposal aims to validate the use of analysing sweat components in fingerprint deposits for to screen for drugs of misuse.
The sweat in a latent fingerprint (LFP) can contain orally ingested drugs and their metabolites a new method for drug detection, is able to incubate LFP with magnetic nanoparticles (NPs)and the LFP treated with a fluorescently labeled secondary antibody allows characterization by fluorescence imaging (Hazarika et al, 2008; 2010). A major research question is whether illicit substances can be detected in a single print as would be the ideal for sampling purposes and if it is possible to detect drugs of different drug classes at one time. The proposed sampling would consist of an individual depositing a fingerprint on a specifically designed template. The print will then be extracted and analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify drugs and drug metabolites. Blood and oral fluid samples will be collected as paired samples to test the valdidty of the procedure and to confirm sensitivity and specificity of the device for use in clinical settings.