title: Disposable screen printed sensor for the electrochemical detection of delta-9-tetrahydrocannabinol in undiluted saliva.
abstract: BACKGROUND
  Cannabis has an adverse effect on the ability to drive safely, therefore a rapid disposable test for Δ(9)-tetrahydrocannabinol (Δ(9)-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 Δ(9)-THC in saliva. Mediator placed in an overlayer was galvanostatically oxidized and reacted with Δ(9)-THC to give an electrochemically active adduct which could be detected by chronoamperometric reduction. Detection of 25-50 ng/mL Δ(9)-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 Δ(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 Δ(9)-THC.
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Ceri
authors.initials: C
authors.lastname: Wanklyn
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Dan
authors.initials: D
authors.lastname: Burton
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Enston
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Carrie-Ann
authors.initials: CA
authors.lastname: Bartlett
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Taylor
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Raniczkowska
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Murdo
authors.initials: M
authors.lastname: Black
authors.affiliation: Oxtox Limited, Warren House, Mowbray Street, Stockport, SK1 3EJ UK.
authors.forename: Lindy
authors.initials: L
authors.lastname: Murphy
keywords: Chronoamperometry; Delta-9-tetrahydrocannabinol; Detection; Galvanostatic oxidation; Mediator; Saliva; Screen printed electrode; Δ9-THC