ABSTRACT
La cantidad de nuevas sustancias psicoactivas (NSP) aumenta en el mercado global cada año. El uso de tecnologías para la producción y la comercialización de las sustancias sintéticas y una demanda exigente de efectos psicotrópicos más potentes son algunos de los factores que contribuyen al incremento de una oferta más variada, así como a la cantidad de consumidores de algún tipo de droga. El desarrollo de herramientas analíticas fiables con capacidad de respuesta in situ para una evaluación preliminar contribuye, significativamente, con la generación de información para atender casos de intoxicaciones, aplicar correctamente la legislación de los países e, inclusive, aportar datos reales para una reclasificación más objetiva de las drogas basada en criterios científicos. Los sensores electroquímicos han ganado terreno en áreas de las ciencias forenses como la toxicología. El uso de tecnologías especializadas para crear electrodos miniaturizados con modificaciones, principalmente con materiales nanoestructurados, guía el desarrollo de dispositivos portátiles de fácil manipulación, altamente versátiles y que requieren micro-cantidades de la muestra. Asimismo, algunos sensores electroquímicos presentan parámetros de desempeño -como límites de detección (LOD) de hasta 0,608 pg/mL, sensibilidad y precisión- que son analíticamente comparables, bajo ciertas condiciones, con las metodologías convencionales acopladas con la espectrometría de masas, las cuales muestran LOD del orden de magnitud entre 10-9 g/mL y 10-12 g/mL para la determinación de algunas drogas. Esta revisión se enfoca en la aplicación y comparación analítica de los sensores electroquímicos voltamperométricos para la determinación de bencilpiperazina (BZP), meta-clorofenilpiperazina (mCPP), 25B-NBO-Me, dimetiltriptamina (DMT), mefedrona (4-MMC), 4-metiletcatinona (4-MEC) y fentanilo (FYL) en representación de las drogas emergentes que se pueden conseguir actualmente en el mercado de las sustancias psicoactivas.
The number of new psychoactive substances (NPS) is increasing on the drug global market every year. New technologies for the production and marketing of synthetic substances, along with a rigorous demand for more powerful psychotropic effects, are some of the factors that contribute to the increase in a more varied supply, as well as the number of drug users. The development of reliable analytical tools with an on-site response capacity for a preliminary determination contributes significantly to the generation of data for the proper care of situations such as poisoning, the correct application of the country's legislation, and even the provision of objective criteria for the reclassification of the substances. Electrochemical sensors have gained ground in areas of forensic science. The use of specialized technologies to manufacture miniaturized electrodes based on modifications, mainly with nanostructured materials, guides the development of versatile easy-to-handle portable devices that require microquantities of the sample. Likewise, some electrochemical sensors have performance parameters such as detection limits (LOD) up to 0.608 pg/mL, sensitivity and precision that are analytically comparable, under certain conditions, with conventional methodologies coupled with mass detection, which show LOD of the order of magnitude between 10-9 g/mL and 10-12 g/mL for drug determination. This review focuses on the application and comparison of voltammetric electrochemical sensors for the determination of benzylpiperazine (BZP), meta-chlorophenylpiperazine (mCPP), 25B-NBO-Me, dimethyltryptamine (DMT), mephedrone (4-MMC), 4-methylethcathinone (4-MEC) and fentanyl (FYL) representing the emerging drugs available to date on the psychoactive substances market.
A quantidade de novas substâncias psicoativas (NSP) sintéticas aumenta a cada ano no mercado global. A utilização de novas tecnologias de produção e comercialização de substâncias, combinado com uma demanda exigente de efeitos psicotrópicos mais potentes, são alguns dos fatores que contribuem para o aumento de uma oferta mais ampla, assim como a quantidade dos números de consumidores de algum tipo de droga. O desenvolvimento de ferramentas analíticas confiáveis e com uma capacidade de resposta in situ para uma avaliação preliminar, contribuem significativamente para a geração de informações científicas para cuidar casos de envenenamento, aplicar corretamente a lei, e até fornecer dados reais para uma reclassificação mais objetiva de drogas com base em critérios científicos. Sensores eletroquímicos ganharam espaço em áreas da ciência forense. A utilização de tecnologias especializadas para criação de eletrodos miniaturizados com modificações, principalmente com materiais nanoestruturados, norteiam o desenvolvimento de dispositivos portáteis altamente versáteis, de fácil manuseio e que necessitam de microquantidades da amostra. Da mesma forma, alguns sensores eletroquímicos apresentam parâmetros de desempenho -como limites de detecção (LOD) até 0.608 pg/mL, sensibilidade e precisão- que são analiticamente comparáveis, sob certas condições, com metodologias convencionais com detecção de massa -mostram LOD de a ordem de grandeza entre 10-9g/mL e 10-12g/mL para a determinação de determinados medicamentos-. Esta revisão tem como foco a aplicação e comparação analítica de sensores eletro-químicos voltamétricos para determinação de benzilpiperazina (BZP), meta-clorofenilpiperazina (mCPP), 25B-NBOMe, dimetiltriptamina (DMT), mefedrona (4-MMC), 4-metilethcatinona (4-MEC) e fentanilo (FYL), que representam os drogas emergentes disponíveis até o momento no mercado de substâncias psicoativas.
ABSTRACT
Fentanyl is a powerful synthetic opioid used to treat severe pain. New administration routes toward its illegal consumption for recreational purposes pose a growing threat to public health, either due to misuse or abuse of this substance. As a result, the rapid qualitative and quantitative determination of fentanyl in biofluids is of great interest. A novel enzymatic biosensor based on adsorptive-stripping cyclic voltammetry is proposed as a cost-effective, reliable, and efficient device for fentanyl determination in urine samples. Disposable screen-printed carbon electrodes modified with multi-walled carbon nanotubes and cytochrome c were used to develop the testing platform. The electrochemical behavior of fentanyl exhibited a well-defined anodic wave around 0.66 V vs. pseudo reference electrode. The experimental conditions were optimized to obtain the best analytical response, and linear regression analysis of increasing concentration standards was applied to estimate the performance parameters. The results suggest a simple method with a wide linearity range, high sensitivity, low limits of detection (0.086 µg/mL) and quantification, and satisfactory precision (2.9% RSD). The feasibility and applicability of the voltammetric approach were assessed by fentanyl-spiked urine samples by standard additions calibration curves in two levels of enrichment with an accuracy of 92% and 100%.
Subject(s)
Biosensing Techniques , Nanotubes, Carbon , Cytochromes c , Fentanyl , ElectrodesABSTRACT
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.
