Enhanced electrochemical detection of illicit drugs in oral fluid by the use of surfactant-mediated solution

Comparison of signal enhancement strategies for carbamazepine detection in undiluted human saliva using an electrochemical sensor with stencil-printed carbon electrodes

“…23 And most recently, in the context of illicit drug detection, Parrilla et al demonstrated that SDS addition produced enhancements in the drug signal within a background of substantially diluted saliva (10-fold with buffer) using commercially-available carbon screen-printed electrodes. 24 A suggested mechanism of SDS action in those systems is that SDS, a negatively charged species with a hydrocarbon tail, adsorbs on the electrode to facilitate electrode interactions with positively-charged dopamine or the protonated forms of the drugs, and inhibits electrode interactions with negatively-charged species, such as the interferents ascorbic acid and uric acid. Finally, SDS has also been applied to the detection of CBZ in buffer (as mentioned above).…”

“…This suggests that SDS facilitates an adsorption-controlled process in our CBZ system, similar to that described by Parilla et al for their system of illicit drug detection. 24 Additional incubation time may provide the critical time required for SDS monolayer formation as observed by Soares et al who monitored SDS monolayer formation in water on their gold electrodes over $10 minutes. 29 The plasma treatment only and the plasma treatment with SDS cases produced CBZ signals that were comparable to one another, and about half the magnitude of the SDS addition alone case for incubation times of 2 and 4 minutes.…”

“…Incubation of sample on the electrode surface is another strategy that has been used to improve electrochemical signal via additional time for the analyte of interest to nd active surface area on the electrode. In particular, Parrilla et al observed increases in signal over an incubation time of 20 minutes for their target analytes (considered multiple illicit drugs) in buffer, 24 while Liu et al reported that SDS addition with accumulation time (i.e., incubation with an applied potential) resulted in signal gains for their target analyte CBZ. 10 So we were motivated to combine sample incubation on the electrodes with SDS addition and/or electrode oxygen plasma treatment to investigate their effects on the CBZ in buffer peak magnitude.…”

Recent Advances in the Use of Surface-Enhanced Raman Scattering for Illicit Drug Detection

“…Ultraviolet-visible (UV-Vis) spectrophotometry [ 3 , 12 ] is a simple and fast method; however, it provides a narrow spectral range and is only fit for the detection of a certain number of drugs [ 13 ]. Fourier transform infrared (FTIR) spectroscopy [ 14 , 15 ] suffers from water interference, while enzyme-linked immunosorbent assays [ 16 , 17 ] cannot match the low detection capabilities of the other methods. Commercial portable detection kits are currently available only for a limited number of drugs and require large sample volumes and specialized reactants [ 18 , 19 ].…”

Rapid on-site Detection of Illicit Drugs in Smuggled Samples with a Portable Electrochemical Device

“…Electrochemical sensors can provide the aforementioned features and, importantly, they can deal with current challenges, providing more reliable results in comparison to commercially available devices [16][17][18]. In this direction, portable and wearable electrochemical sensors have been designed for the detection of illicit drugs using different configurations such as a glove-based sensor [19] as well as for their determination in biofluids [20]. The electrochemical approach is based on the characteristic electrochemical profile of each compound that reveals the electroactive functionalities of the target compound [21].…”