Existing methods for drug detection
Urine is considered the gold standard sample source for non-invasive drug testing, but saliva, sweat, and hair are becoming promising sources for testing. Because drugs of abuse have short half lives in the body, methods used for detection need to be sensitive. Commonly used methods for detection include gas chromatography, mass spectrometry, Raman spectroscopy, and nuclear magnetic resonance. However, these instruments are not readily accessible or portable, are costly, and require extensive training to operate.
Therefore, a point-of-care test for drug monitoring needs to be miniaturized, affordable, flexible, easy to use, and highly sensitive. Because the use of a stimulant and a depressant together is becoming one of the most common fatal drug abuse methods, it’s important for a sensor to detect more than one drug simultaneously.
In recent years, scientists have developed a multiplex immunosensor to detect morphine, tetrahydrocannabinol, and benzoylecgonine from urine in 40 minutes2 and electrochemical methods for detecting amphetamine type stimulants3 but no point-of-care assay currently exists to detect all families of commonly abused drugs simultaneously. Lateral flow assays are easy to use and portable but can have low sensitivity and provide only qualitative or semi-quantitative data.
To address these gaps in drug monitoring assays, a global team of scientists created a multiplex point-of-care sensor for simultaneously detecting amphetamine (AMP), cocaine (COC), and benzodiazepine (BZD) from saliva1. (Figure 1)
Figure 1. Saliva samples added to an antibody-based multiplex drug detection platform provides readouts on a smartphone1.