Abstract:BackgroundGiven that Δ9-tetrahydrocannabinol, the active constituent of cannabis, has been shown to greatly reduce driving ability, thus being linked to many drug driving accidents, its reliable detection is of great importance.ResultsAn optimised carbon paste electrode, fabricated from graphite powder and mineral oil, is utilised for the sensitive detection of Δ9-tetrahydrocannabinol (THC) in both aqueous solutions of pH 10.0 and in synthetic saliva solutions. “Absorptive Stripping Voltammetry” is exploited t… Show more
“…In an effort to quickly respond to a growing need to streamline the delivery of results, several alternative drug testing approaches have been recently suggested [ 8 , 9 ]. For example, electrochemical techniques such as voltammetry [ 10 , 11 , 12 , 13 ] and amperometry have been utilized as novel forensic tools for the detection of drugs [ 14 , 15 ]. These electrochemical techniques adapt well to the required field conditions [ 16 ], offering screening opportunities that can provide on-site decisions to law enforcement before sending evidence to the forensic lab for later analysis and processing [ 17 ].…”
The synthetic cathinones mephedrone (4-MMC) and 4-methylethcathinone (4-MEC) are two designer drugs that represent the rise and fall effect of this drug category within the stimulants market and are still available in several countries around the world. As a result, the qualitative and quantitative determination of ‘legal highs’, and their mixtures, are of great interest. This work explores for the first time the spectroelectrochemical response of these substances by coupling cyclic voltammetry (CV) with Raman spectroscopy in a portable instrument. It was found that the stimulants exhibit a voltammetric response on a gold screen-printed electrode while the surface is simultaneously electro-activated to achieve a periodic surface-enhanced Raman spectroscopy (SERS) substrate with high reproducibility. The proposed method enables a rapid and reliable determination in which both substances can be selectively analyzed through the oxidation waves of the molecules and the characteristic bands of the electrochemical SERS (EC-SERS) spectra. The feasibility and applicability of the method were assessed in simulated seized drug samples and spiked synthetic urine. This time-resolved spectroelectrochemical technique provides a cost-effective and user-friendly tool for onsite screening of synthetic stimulants in matrices with low concentration analytes for forensic applications.
“…In an effort to quickly respond to a growing need to streamline the delivery of results, several alternative drug testing approaches have been recently suggested [ 8 , 9 ]. For example, electrochemical techniques such as voltammetry [ 10 , 11 , 12 , 13 ] and amperometry have been utilized as novel forensic tools for the detection of drugs [ 14 , 15 ]. These electrochemical techniques adapt well to the required field conditions [ 16 ], offering screening opportunities that can provide on-site decisions to law enforcement before sending evidence to the forensic lab for later analysis and processing [ 17 ].…”
The synthetic cathinones mephedrone (4-MMC) and 4-methylethcathinone (4-MEC) are two designer drugs that represent the rise and fall effect of this drug category within the stimulants market and are still available in several countries around the world. As a result, the qualitative and quantitative determination of ‘legal highs’, and their mixtures, are of great interest. This work explores for the first time the spectroelectrochemical response of these substances by coupling cyclic voltammetry (CV) with Raman spectroscopy in a portable instrument. It was found that the stimulants exhibit a voltammetric response on a gold screen-printed electrode while the surface is simultaneously electro-activated to achieve a periodic surface-enhanced Raman spectroscopy (SERS) substrate with high reproducibility. The proposed method enables a rapid and reliable determination in which both substances can be selectively analyzed through the oxidation waves of the molecules and the characteristic bands of the electrochemical SERS (EC-SERS) spectra. The feasibility and applicability of the method were assessed in simulated seized drug samples and spiked synthetic urine. This time-resolved spectroelectrochemical technique provides a cost-effective and user-friendly tool for onsite screening of synthetic stimulants in matrices with low concentration analytes for forensic applications.
“…The literature involving voltammetric determination of Δ9-THC comprehends the use of electrodes with and without chemical modification. There are methodologies for its detection when in seized samples [26][27][28][29][30] , and in saliva 31,32 . However, it should be noted that in the literature only a few studies with artificial saliva have been reported for the electrochemical detection of Δ9-THC 33 .…”
Currently, marijuana or cannabis is the most consumed drug worldwide, and is also the one with the highest number of seizures, with 354 tons seized in Brazil in 2017. The increase in its consumption has been called attention, not only by the authorities, due to accidents caused when driving under the influence of the drug, but also by companies that carry out toxicological analyzes on their employees. For this, rapid tests, such as colorimetric tests, are generally used to analyze the urine of users. The need for agile and proper identification of drugs of abuse has encouraged the scientific community to improve and to develop new methodologies. Electrochemical methods appear as a cheap, portable and easy to use alternative. The use of biodegradable materials for the development of disposable electrodes has become paramount today. The use of 3D printers emerges as an alternative for the manufacture of these electrodes and the use of saliva instead of urine, has also been a priority because it is a less invasive sample and difficult to adulterate. In this work, a three dimensional device was created in an innovative way containing the three electrodes, working, counter and reference, in conductive material. The device was then used to detect the active principle present in cannabis, delta-9-tetrahydrocannabinol, in aqueous solution, and its metabolite, 11-nor-9-carboxy-THC, in samples of real saliva, both through cyclic voltammetry. The positive results show that the proposed device can be used, as well as those already found on the market, for the identification of drug use and in the forensic field.
Section: Cannabinoids and The Coronavirusmentioning
confidence: 99%
“…The fabrication of this sensor is presented in Figure 10 c/d. Sensors based on Absorptive stripping voltammetry [ 242 ], porous carbon paper [ 237 ], molecularly imprinted polymers (MIPs)( Figure 10 a) [ 241 ] have also produced highly sensitive electrodes capable of sensing concentrations of 31.5, 1.26 and 0.18 ng of THC/mL respectively.…”
Section: Cannabinoids and The Coronavirusmentioning
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