Stockport, United Kingdom
Stockport, United Kingdom

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Wanklyn C.,Oxtox Ltd | Burton D.,Oxtox Ltd | Enston E.,Oxtox Ltd | Bartlett C.-A.,Oxtox Ltd | And 4 more authors.
Chemistry Central Journal | Year: 2016

Background: Cannabis has an adverse effect on the ability to drive safely, therefore a rapid disposable test for Δ9-tetrahydrocannabinol (Δ9-THC), the psychoactive component of cannabis, is highly desirable for roadside testing. Results: A screen printed carbon electrode is used for the N-(4-amino-3-methoxyphenyl)-methanesulfonamide mediated detection of Δ9-THC in saliva. Mediator placed in an overlayer was galvanostatically oxidized and reacted with Δ9-THC to give an electrochemically active adduct which could be detected by chronoamperometric reduction. Detection of 25-50 ng/mL Δ9-THC spiked into undiluted saliva was achieved with a response time of 30 s. A trial of the sensors with four cannabis smokers showed sensitivity of 28 %, specificity of 99 % and accuracy of 52 %. Conclusions: Rapid electrochemical detection of Δ9-THC in undiluted saliva has been demonstrated using a disposable sensor, however the sensitivity is lower than acceptable. Further optimization of the assay and sensor format is required to improve the sensitivity of response to Δ9-THC. © 2016 Wanklyn et al.


Bartlett C.-A.,Oxtox Ltd | Taylor S.,Oxtox Ltd | Fernandez C.,Oxtox Ltd | Wanklyn C.,Oxtox Ltd | And 5 more authors.
Chemistry Central Journal | Year: 2016

Background: Methamphetamine 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. Results: A 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. Conclusions: Using 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. © 2016 Bartlett et al.


Patent
OXTOX Ltd | Date: 2010-01-28

The invention provides a method of assaying for tetrahydrocannabinol in a body fluid, said method comprising contacting a sample of body fluid with an imine capable of reacting with tetrahydrocannabinol to yield a quinone imine, and detecting the formation of a quinone imine, characterised in that said sample is contacted with said reagent compound at a pH of at least 10.5.


A device combining a fuel-cell-type breathalyser with an electrochemical saliva drug test. The saliva drug tester comprises a disposable test strip-electrode module assembly and an analyser module. The saliva is squeezed out of an absorbent swab when the test strip is inserted into the electrode module. The electrode module can also carry information that is read and evaluated by the analyser, e.g. for verification of the electrode module.


Cannabis has an adverse effect on the ability to drive safely, therefore a rapid disposable test for (9)-tetrahydrocannabinol ((9)-THC), the psychoactive component of cannabis, is highly desirable for roadside testing.A screen printed carbon electrode is used for the N-(4-amino-3-methoxyphenyl)-methanesulfonamide mediated detection of (9)-THC in saliva. Mediator placed in an overlayer was galvanostatically oxidized and reacted with (9)-THC to give an electrochemically active adduct which could be detected by chronoamperometric reduction. Detection of 25-50ng/mL (9)-THC spiked into undiluted saliva was achieved with a response time of 30s. A trial of the sensors with four cannabis smokers showed sensitivity of 28%, specificity of 99% and accuracy of 52%.Rapid electrochemical detection of (9)-THC in undiluted saliva has been demonstrated using a disposable sensor, however the sensitivity is lower than acceptable. Further optimization of the assay and sensor format is required to improve the sensitivity of response to (9)-THC.


PubMed | Oxtox Ltd
Type: | Journal: Chemistry Central journal | Year: 2016

Methamphetamine 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.A 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 55s and lower detection limit of 400ng/mL.Using 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.

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