Disposable screen printed sensor for the electrochemical detection of methamphetamine in undiluted saliva

Abstract

BackgroundMethamphetamine has an adverse effect on the ability to drive safely. Police need to quickly screen potentially impaired drivers therefore a rapid disposable test for methamphetamine is highly desirable. This is the first proof-of-concept report of a disposable electrochemical test for methamphetamine in undiluted saliva.ResultsA screen printed carbon electrode is used for the N,N′-(1,4-phenylene)-dibenzenesulfonamide mediated detection of methamphetamine in saliva buffer and saliva. The oxidized mediator reacts with methamphetamine to give an electrochemically active adduct which can undergo electrochemical reduction. Galvanostatic oxidation in combination with a double square wave reduction technique resulted in detection of methamphetamine in undiluted saliva with a response time of 55 s and lower detection limit of 400 ng/mL.ConclusionsUsing a double square wave voltammetry technique, rapid detection of methamphetamine in undiluted saliva can be achieved, however there is significant donor variation in response and the detection limit is significantly higher than desired. Further optimization of the assay and sensor format is required to improve the detection limit and reduce donor effects.Electronic supplementary materialThe online version of this article (doi:10.1186/s13065-016-0147-2) contains supplementary material, which is available to authorized users.

Saliva diagnostics – Current views and directions

“…Those technologies enable to measure proteins, DNA, transcripts (mRNA), electrolytes, and small molecules in saliva. 162 Currently developed tools include electrochemical sensing, 189 on-chip qRT-PCR, 190 fiber optic microsphere-based arrays, 191 high-throughput DNA microarrays, 192 surface plasmon resonance-based fiber optic sensors, 193 and microchip-based electrophoretic immunoassay. 137 The new avenue of point-of-care diagnostics for ''lab-ona-chip'' provides a new facet of point-of-care diagnostics, because it concurrently enables the detection of multiple biomarkers, and thus simultaneous diagnosis of many diseases.…”

Electrochemiluminescent screening for methamphetamine metabolites

“…2016 marked the first use of a disposable electrode for the detection of MA, within undiluted saliva samples, through utilisation of N,N′-(1,4-phenylene)-dibenzenesulfoamide as a mediator. 25 Although this work was promising for the detection of MA via portable electrochemical methodologies within biological matrices, the detection limits achieved lay outwith the clinically relevant range. Detection limits for MA have been improved via utilisation of ECL sensors, through employment of the traditional luminophore, [Ru(bpy) 3 ] 2+ , facilitating mediated oxidation of the amine moiety within the species.…”

“…Furthered though the proven ability of ECL sensors to offer direct drug detection within range of complex matrices, including biological fluids, without the requirement of any separation or purification strategies. [16][17][18][19][20][21][22][23][24][25][26][27] The detection of MA within biological fluids adopts a twopronged approach, whereby identification of MA abuse is paired with detection of AMP as one of its primary metabolites. 8,[28][29][30] Following ingestion, MA is readily absorbed into the blood stream, with excretion primarily though the renal system following hepatic metabolism, resulting in the primary metabolites; AMP following the N-demethylation process and para-hydroxymethamphetamine ( p-OHMA) following para-hydroxylation.…”

Screen-Printed Electrodes (SPE) for In Vitro Diagnostic Purpose

“…Screen-printed sensors were also used to detect methamphetamine. The researchers used a screen-printed carbon electrode and a mediator (N,N′-(1,4-phenylene)-dibenzenesulfonamide) that once oxidized will react with methamphetamine (MAMP) and form an adduct that can be subjected to electrochemical reduction [ 42 ]. Using a double square wave voltammetry technique, they were able to detect concentrations of MAMP as low as 400 ng/mL in 55 s. They concluded that although the response time of the sensor was very good, the detection limit was higher than what currently used methods can ensure and further work is needed for the improvement of the method.…”