New psychoactive substances (NPS) are a broad category of drugs that pose public health risks and have poorly characterized pharmacological properties. Further studies are critical for risk assessment, toxicological profiling, and intoxication management. Human evaluations are limited by ethical and safety constraints, making animal models essential. Among in vivo models, zebrafish (Danio rerio) deserves emphasis in the study of NPS due to neurobehavioral, metabolic, and toxicological alterations. Considering some advantages, such as high genetic and neurochemical homology to humans, small body size, external fertilization, and embryo-larval transparency, zebrafish is well-suited for high-throughput screening of NPS. Their central nervous system shares key neurotransmitter pathways with mammals, supporting neurobehavioral assays. Also, a conserved cytochrome P450 system allows metabolism studies. Zebrafish have been successfully used to investigate NPS effects, with embryo-larval models offering practical advantages for acute toxicity and high-throughput behavioral screening. Adults, in turn, are more appropriate for complex behaviors and long-term or chronic exposure protocols. This review synthesizes for the first time behavior, toxicology, and metabolism data from zebrafish studies with a range of NPS classes within a unifying framework, to deliver a comprehensive understanding of their in vivo activity. By focusing on the translational value of zebrafish research, this review bridges experimental toxicology and clinical and forensic applications, thus filling a significant gap in current knowledge and demonstrating how zebrafish models can uniquely accelerate NPS toxicity profiling by providing mechanistic and behavioral information with high translational value.
Atropine is crucial in forensic investigations due to its role in poisoning cases, requiring precise detection methods. We propose a novel dual-mode analytical platform that combines screen-printed graphite electrodes with square-wave voltammetry and a colorimetric reaction using bromocresol green. This dual platform provides three distinct analytical responses: a colour change via the colorimetric reaction and electrochemical responses before and after the colorimetric reaction, allowing robust atropine identification. For the first time, the electrochemical behaviour of atropine in the presence of bromocresol green has been investigated, with mechanistic insights elucidated through NMR analysis. Although atropine alone undergoes an irreversible oxidation process, the colorimetric reaction facilitates a redox process involving bromocresol green, allowing indirect atropine detection. The real-world applicability of this dual-sensing platform is demonstrated by detecting atropine in drink and biological samples for potential spiking and poisoning diagnosis. Importantly, the platform is shown to function within solutions containing quinine, proving its suitability to analysing strong and bitter tonic water drink with low atropine concentrations, overcoming this known analytical problem. The developed method exhibited a wide linear range (0.001–0.4 mg mL−1), a low limit of detection (0.255 μg mL−1), and excellent stability with relative standard deviation lower than 7 %. Interference studies confirm the method’s selectivity, and atropine recoveries from drink and biological samples were close to 100 %. The proposed platform is a simple, rapid, and selective screening tool, and shows significant potential for forensic applications in atropine detection.
Synthetic Cannabinoid Receptor Agonists (SCRAs) are a class of Novel Psychoactive Substances (NPS) that interact with the same receptors (CB1 and CB2) as delta-9-tetrahydrocannabinol (THC). The identification of SCRAs, such as AB-CHMINACA and MDMB-4en-PINACA, is of significant forensic and toxicological interest due to their widespread consumption in several countries and their potential involvement in overdose cases resulting from their high potency, posing a serious public health and safety concern. Currently, no standardized screening methods exist for the detection of SCRAs in forensic and toxicological contexts. This study introduces a novel electroanalytical method that combines laboratory-fabricated boron-doped diamond screen-printed electrodes (SP/BDDE) with square-wave adsorptive stripping voltammetry (SWAdSV) for the detection of AB-CHMINACA and MDMB-4en-PINACA in e-cigarette samples and real biological matrices. For the first time, the electrochemical behavior of these SCRAs is comprehensively investigated, and all their redox processes (Pc1/Pa2 and Pa3) are utilized for selective and accurate identification. The proposed method exhibited a wide linear range (20–100 μM for AB-CHMINACA and 20–70 μM for MDMB-4en-PINACA) with a low detection limit of 0.282 μM, making it highly suitable for forensic applications involving seized samples and toxicological analyses of biological specimens. The stability of the electrochemical response was assessed, with SP/BDDE showing relative standard deviations (RSD) below 10 % for Ep and Ip. Interference studies confirmed the high selectivity of the method for SCRA detection. AB-CHMINACA and MDMB-4en-PINACA were successfully identified in e-cigarette and biological samples, with recovery rates approaching 100 %, indicating minimal matrix effects in these complex samples. Therefore, the proposed method proves to be a promising, rapid, and selective screening approach for the detection of SCRAs in forensic and toxicological scenarios, as a screening test.
The use of 3D-printed electrodes is reported fabricated from in-house conductive filament composed of a mixture of recycled poly (lactic acid) (rPLA), graphite (Gpt), and carbon black (CB) for fast detection of the abused drug ketamine. Firstly, the performance of these electrodes was evaluated in comparison to 3D-printed electrodes produced employing a commercially available conductive filament. After a simple pretreatment step (mechanical polishing), the new 3D-printed electrodes presented better performance than the electrodes produced from commercial filament in relation to peak-to-peak separation of the redox probe [Fe(CN)6]3-/4- (130 mV and 759 mV, respectively), charge transfer resistance (Rct = 1.04 ± 0.05 kΩ and 9.62 ± 0.03 kΩ, respectively), and heterogeneous rate constant (k0 = 7.16 ± 0.05 × 10–3 cm s−1 and 3.57 ± 0.03 × 10–3 cm s-1, respectively). Excellent analytical characteristics for the detection of ketamine were achieved, including wide linear range (10 to 250 μmol L-1), excellent sensitivity (0.024 ± 0.001 μA μmol L-1), low limit of detection (LOD = 0.7 μmol L-1), and recovery values from 82 to 115% for beverage samples (white and red wines, beer, water, and vodka) spiked with the abused drug ketamine.
Introduction: Mechanisms that dictate the preference for ethanol and its addiction are not only restricted to the central nervous system (CNS). An increasing body of evidence has suggested that abusive ethanol consumption directly affects the immune system, which in turn interacts with the CNS, triggering neuronal responses and changes, resulting in dependence on the drug. It is known that neuroinflammation and greater immune system reactivity are observed in behavioral disorders and that these can regulate gene transcription. However, there is little information about these findings of the transcriptional profile of reward system genes in high consumption and alcohol preference. In this regard, there is a belief that, in the striatum, an integrating region of the brain reward system, the interaction of the immune response and the transcriptional profile of the Lrrk2 gene that is associated with loss of control and addiction to ethanol may influence the alcohol consumption and preference. Given this information, this study aimed to assess whether problematic alcohol consumption affects the transcriptional profile of the Lrrk2 gene, neuroinflammation, and behavior and whether these changes are interconnected.
Methods: An animal model developed by our research group has been used in which male C57BL/6 mice and knockouts for the Il6 and Nfat genes were subjected to a protocol of high fat and sugar diet intake and free choice of ethanol in the following stages: Stage 1 (T1)—Dietary treatment, for 8 weeks, in which the animals receive high-calorie diet, High Sugar and Butter (HSB group), or standard diet, American Institute of Nutrition 93-Growth (AIN93G group); and Stage 2 (T2)—Ethanol consumption, in which the animals are submitted, for 4 weeks, to alcohol within the free choice paradigm, being each of them divided into 10 groups, four groups continued with the same diet and in the other six the HSB diet is substituted by the AIN93G diet. Five groups had access to only water, while the five others had a free choice between water and a 10% ethanol solution. The weight of the animals was evaluated weekly and the consumption of water and ethanol daily. At the end of the 12-week experiment, anxiety-like behavior was evaluated by the light/dark box test; compulsive-like behavior by Marble burying, transcriptional regulation of genes Lrrk2, Tlr4, Nfat, Drd1, Drd2, Il6, Il1β, Il10, and iNOS by RT-qPCR; and inflammatory markers by flow cytometry. Animals that the diet was replaced had an ethanol high preference and consumption.
Results and discussion: We observed that high consumption and preference for ethanol resulted in (1) elevation of inflammatory cells in the brain, (2) upregulation of genes associated with cytokines (Il6 and Il1β) and pro-inflammatory signals (iNOS and Nfat), downregulation of anti-inflammatory cytokine (Il10), dopamine receptor (Drd2), and the Lrrk2 gene in the striatum, and (3) behavioral changes such as decreased anxiety-like behavior, and increased compulsive-like behavior. Our findings suggest that interactions between the immune system, behavior, and transcriptional profile of the Lrrk2 gene influence the ethanol preferential and abusive consumption.
This study introduces a new approach that combines the benefits of colorimetric and electrochemical techniques for the selective detection of 3,4-methylenedioxymethamphetamine (MDMA) in forensic samples using a 3D-printed electrochemical device. We propose and implement a two-step strategy integrating Simon’s test with differential pulse adsorptive stripping voltammetry (AdSDPV). Simon’s test employs sodium nitroprusside, acetaldehyde, and sodium carbonate, while the electrochemical analysis is performed using AdSDPV on a 3D-printed graphite/polylactic acid (Gr/PLA) electrode in a dual-cell configuration. Initially, MDMA is identified by a color shift from pink to dark purple in Simon’s test and is subsequently confirmed by observing changes in the electrochemical behavior on the 3D-printed Gr/PLA electrode, both before and after the colorimetric reaction. MDMA exhibits two characteristic oxidation processes: O1 at +0.9 V and O2 at +1.1 V (vs. Ag pseudo-reference). Following Simon’s test, an additional oxidation process emerges with a distinct peak potential (PSimon) at +0.38 V (vs. Ag pseudo-reference). Moreover, the peak currents of O1 and O2 decrease after the Simon’s test reaction, further confirming the MDMA presence. The method demonstrates a broad linear range (1 to 175 µM) and a low limit of detection (0.1 µM) for MDMA. It achieves a good stability in electrochemical responses (RSD < 5 %) using either a single electrode (N = 5) or different electrodes (N = 3). The integrated approach, combining Simon’s test and AdSDPV, effectively identifies MDMA, even in samples containing 3,4-methylenedioxyamphetamine (MDA). This method provides a robust, straightforward, and rapid selective screening tool for MDMA identification and quantification, leveraging three distinct responses: one colorimetric and two electrochemical (pre and post colorimetric reaction).
Lysergic acid diethylamide (LSD) and phenylethylamine derivatives (NBOHs and NBOMes) are commonly found on seized blotter papers, posing public health risks. Efficient screening methods for identifying these substances are currently limited. To address this, a novel protocol combining colorimetric and electrochemical techniques was developed as a screening method for drugs of abuse in blotter papers. The method uses Emerson’s colorimetric reagent (CR) for NBOH identification combined with voltammetric detection via differential pulse stripping adsorptive voltammetry (AdSDPV) using graphite screen-printed electrodes (SPE-Gr). This approach offers, for the first time, an unambiguous identification of NBOHs through three analytical responses: (1) a color change following the addition of the CR; (2) an electrochemical signal indicating the NBOHs’ redox process; and (3) a selective electrochemical signal of the colorimetric reaction product (CR-NBOH) on SPE-Gr. It also differentiates NBOH, NBOMes, 2Cs, and LSD, enabling rapid identification of drugs commonly found in blotter papers. Compared to previous sensors, this method provides selective detection of these drugs at the same pH, offering simplicity for forensic applications. The proposed method showed strong electrochemical stability with low variability (<2.3% RSD) and a low detection limit (0.3 μg mL–1) over a wide linear range (10–1000 μg mL–1), offering a simple and fast quantitative analysis of illicit drugs in these materials. The combined method was successfully applied to 33 real seized samples, with results confirmed by definitive methods.
Clobenzorex (CBZ) is a stimulant drug, recognized for its anorectic potential, legally used in some countries for obesity treatment. However, CBZ is banned in much of the world and has been often used illegally by drivers needing to stay alert for extended periods. Therefore, the rapid identification of CBZ in forensic samples is of paramount importance for public health and safety. In this context, we introduce an innovative electroanalytical screening method for detecting CBZ in seized tablet samples and human oral fluid using voltammetry with a graphite screen-printed electrode (SPE-Gr). The electrochemical detection was optimized in phosphate buffer solution (0.1 mol L−1, pH 7.0) using square wave voltammetry (SWV). The SPE-Gr combined with SWV exhibited a good stability of the electrochemical responses for CBZ detection, with a relative standard deviation of less than 5% across different days (N = 5) and using different SPEs (N = 3). A linear detection range of 2.5–100.0 μmol/L (R2 = 0.992) was achieved, with a low limit of detection (LOD) of 0.32 μmol L−1. Interference studies with other illicit drugs and adulterants confirmed the selectivity of the proposed method for CBZ detection. In addition, the presence of CBZ in seized tablet samples and authentic oral fluids, collected from drivers, was detected and identified using the proposed method, which results were also confirmed by HPLC-MS. Consequently, integrating SPE-Gr with SWV offers a reliable, rapid, sensitive, selective, reproducible, and direct approach for the preliminary qualitative and quantitative analysis of CBZ in forensic contexts. Furthermore, the proposed method provides an efficient oral fluid test for CBZ screening in drivers under the influence of drugs.
4-Methylpentedrone, also known as 4-MPD, is a drug belonging to the class of synthetic cathinones (SCs) widely reported for recreational use due to its potent stimulant effects. The preliminary identification of SCs in seized samples is of great interest in the forensic setting. In this context, we present an attractive screen-printed electrode for SC detection in forensic samples, using 4-MPD as a model analyte. In the quest for sensors with more environmentally friendly characteristics, polyethylene terephthalate (PET) from discarded beverage bottles (recyclable) was repurposed as a substrate for conductive ink deposition featuring glass varnish and carbon nanotubes (CNTs-GV/PET). Characterization studies of CNTs-GV/PET showed that the conductive ink is versatile and robust for application in electroanalysis. The electrochemical detection of 4-MPD was optimized in 0.1 mol/L phosphate buffer at pH 8.0 using the square wave voltammetry (SWV), where this drug exhibited one oxidation and two reduction processes on the CNTs-GV/PET. The proposed method provided a wide linear range for 4-MPD determination (1.0–100.0 µmol/L) with a low limit of detection (0.1 µmol/L). Under optimized conditions, SWV profiles of adulterants and other twelve illicit drugs, commonly found in seizures containing SCs, demonstrated that the proposed method is highly selective for 4-MPD screening in forensic samples. Therefore, the proposed method offers a simple, selective, and environmentally friendly approach for SC detecting with great potential for application in forensic analysis.
This work aimed to present the production of a Certified Reference Material (CRM) of methamphetamine hydrochloride, as an important tool to ensure the quality of forensic results. Methamphetamine is a synthetic drug derived from amphetamine, which potentially stimulates the central nervous system, and its prolonged use can cause excessive anxiety, euphoria, bipolar disorder, and psychosis, among other health damages. To produce this batch of CRM, homogeneity and transport stability studies were carried out by High-Performance Liquid Chromatography with Photodiode Array Detection (HPLC-PDA) using the results of chromatographic area corrected by the mass fraction of the sample in the analyzed solution. Evaluation of stability under storage conditions and characterization of the material were performed by 1H qNMR, a ratio primary measurement procedure. The CRM showed neither considerable heterogeneity nor a tendency to instability under transport conditions (temperature of 50 °C up to 21 days) and storage conditions (20–25 °C). The certified purity value of methamphetamine hydrochloride was (999 ± 12) mg/g, equivalent to a mass fraction of (99.9 ± 1.2) g / (100 g), (k = 2).
Cannabis sativa L. is a plant with diverse applications, but remains the most widely used illicit substance worldwide. Its classification as a drug of abuse, along with socio-economic concerns, has led to its prohibition in numerous countries, including Brazil, where its consumption, cultivation, and sale are strictly prohibited. This regulatory context highlights the need for reliable and accurate methods for cannabis identification. In this study, three straightforward and efficient analytical methods were developed for the identification of Cannabis sativa, using simple extraction procedures followed by ATR-FTIR spectroscopy. Three solvents were evaluated: chloroform and petroleum ether, both combined with Fast Blue B salt, and ethanol, employed as a standalone solvent. Optimized spectral regions (1550–1650 cm−1 for ethanol and petroleum ether; 800–880 cm−1 for chloroform) and preprocessing techniques, such as Standard Normal Variate (SNV) and mean centering, resulted in a robust PLS-DA model. The method exhibited a low incidence of outliers (0.4 %–1.6 %), minimal false-negative and false-positive error rates (1.1 %–2.8 % and 0.0 %–3.0 %, respectively). Ethanol performed as the best and greener method, with an efficiency of 99.4 %, no residual generation, and eliminating the need for bonding agents like Fast Blue B salt. It also aligns with green chemistry principles, making it safer for analysts and the environment. Overall, the proposed method offers a reliable, accurate, and sustainable alternative for the forensic identification of Cannabis sativa, effectively addressing the limitations of conventional screening techniques and the complexity of plant-based mixtures.
Background
Paracetamol or acetaminophen (APAP), or acetaminophen, is a widely used medication for pain relief and fever reduction due to its analgesic and antipyretic properties. However, excessive APAP consumption can lead to severe hepatotoxicity and nephrotoxicity, posing overdose risks. Consequently, the development of analytical methods for an accurate and rapid detection of APAP in biological matrices is of great interest in the health-related fields. Electrochemical methods have emerged as efficient, cost-effective, and sensitive tools for APAP detection in biological samples. In the light of the reported insights, this review examines critically diverse electrochemical methods for PAR detection in different biological matrices, including serum, urine, oral fluid, and sweat.
Results
Significance
Forensic laboratories play a pivotal role in identifying and quantifying drugs in police seizures, often using spectroscopic techniques in combination with chromatographic methods that rely on chemical reference substances (CRS). The demand for a wide variety of CRS is critical, not only for common drugs like cocaine but also for the rapidly increasing number of new psychoactive substances (NPS), which emerge weekly. However, acquiring CRS is costly and bureaucratic because of the restricted circulation of these substances. Nuclear magnetic resonance (NMR) offers a viable alternative to identifying and quantifying substances without the need for specific CRS for each analyte. Although NMR equipment is commonly available at universities, it is typically absent from police laboratories because of its high initial cost. This work highlights a successful partnership between a forensic laboratory and university-based NMR facilities as a cost-effective strategy for obtaining CRS. A case study involving four substances—cocaine, two recently scheduled NPS, metonitazene and dipentylone, and ADB-5′Br-BUTINACA—demonstrates the effectiveness of this collaboration. This partnership allowed the generation of conclusive reports for seized substances, providing early warnings about NPS and helping to prevent potential outbreaks and public health crises. Additionally, the strategy facilitated the acquisition of expensive CRS from samples that would otherwise be destroyed, at a reduced cost and within a shorter timeframe. Furthermore, this partnership enhances student training in advanced instrumental analysis and research, showcasing the benefits of collaboration between forensic and academic institutions.
In response to the growing need for sustainable analytical methods, this study explores the repurposing of screen-printed electrodes (SPEs) that would otherwise be discarded. This involves recoating the working electrode surface with a graphite (Gr) and chitosan (CTS) dispersion, creating a reusable SPE (SPE-Gr/CTS). Demonstrating its utility, SPE-Gr/CTS was employed for the detection of 4-bromo-2,5-dimethoxyphenethylamine (2C-B), a phenylethylamine commonly used for recreational proposes. Identifying 2C-B in fluid oral and seized samples is of great interest for forensic and toxicological applications. The 2C-B detection using SPE-Gr/CTS was optimized in Britton–Robinson buffer solution (0.1 mol L−1) at pH 2.0, employing square-wave adsorptive stripping voltammetry. The electrochemical behavior of 2C-B on SPE-Gr/CTS exhibited one irreversible oxidation and a reversible redox process. The proposed method presented a dynamic linear range for 2C-B determination (0.05 to 7.5 μmol L−1) with a low LOD (0.015 μmol L−1). Moreover, the stability of 2C-B electrochemical responses on SPE-Gr/CTS was confirmed using the same or different electrodes (N = 3), with a relative standard deviation of less than 5.0%. Interference studies with seventeen other illicit drugs and adulterants demonstrated that the proposed method is selective for 2C-B detection even in the presence of these substances. Real seized and oral fluid samples containing 2C-B were analyzed using this method, and the results were confirmed by LC-MS. The proposed device demonstrates to be an environmentally friendly and selective sensor for 2C-B detection in forensic analysis, offering a rapid and straightforward screening method for seized and biological samples. In addition, a portable and sensitive determination of 2C-B in forensic samples is presented with minimal sample consumption (50 μL).
Flexible graphite paper is a promising material for constructing low-cost and portable electrochemical devices. Herein, we propose a fast (10 s) electrochemical treatment (+5.0 V vs Ag|AgCl|KCl(sat.)) in a basic medium (0.5 mol L−1 NaOH solution) to enhance the electrochemical performance of graphite paper. The cyclic voltammetric response of a 1:1 mmol L−1 [Fe(CN)6]3-/4− solution in 0.1 mol L−1 KCl at 50 mV s−1 demonstrated improved electrochemical reversibility (from ΔEp = 1032 ± 6 mV to 176 ± 10 mV), enhanced ratio of anodic (Ipa) and cathodic (Ipc) current intensities (from Ipa/Ipc = 0.30 ± 0.00 to 0.99 ± 0.03), and a significant increase in current intensity (from 10.1 ± 0.1 µA to 28.1 ± 0.6 μA) for untreated and treated surfaces, respectively. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of treated graphite sheet electrodes showed a high number of flakes and Raman spectroscopy revealed more structural defects (measured by D/G bands ratios), which can explain the better voltammetric profile of the redox probe. These results agreed with the estimation of electroactive area which increased 2.2 times after the treatment. Cyclic voltammetric experiments reveal that the surface treatment improved the current responses towards the oxidation of different molecules, such as morphine, ascorbic acid, dopamine, hydroxychloroquine, paracetamol and ciprofloxacin. To demonstrate the potential applicability of treated graphite sheets, morphine, an important opioid used as a medical agent and often reported as overdose cases, was determined in pharmaceutical (tablet), spiked synthetic urine and saliva samples, using differential-pulse voltammetry. Linear ranges of 0.1–20.0 and 20.0–80.0 µmol L−1, with a limit of detection value of 0.08 µmol L−1, were achieved for morphine. Appropriate apparent recovery values (∼92 %) were also obtained for sample analysis.
Background
Alcohol use disorder (AUD) is a complex condition affecting several body systems. Gut microbiota alterations, intestinal-barrier disruption, and the consequent translocation of metabolites foster chronic inflammation, lower short-chain fatty acid (SCFA) output, and depleted beneficial bacteria may contribute to transcriptional, epigenetic, and metabolic changes that influence ethanol preference.
Methods
Two experimental phases were used. T1 (8 weeks): mice received either the American Institute of Nutrition standard diet (AING) or a high-sugar-butter (HSB) diet. T2 (4 weeks): HSB animals switched to AING (SWITCH), while AING mice maintained the same diet. Each diet arm was split into ethanol (EtOH; free access to 10% ethanol) or H2O, generating four groups (AING + H2O, AING + EtOH, SWITCH + H2O, and SWITCH + EtOH). Sample processing involved colonic-content collection, 16S rRNA sequencing, microbiome profiling, functional inference, metabolic-network analysis, and SCFA/amino acid quantification.
Results
SWITCH + EtOH mice displayed high ethanol consumption and preference, whereas AING + EtOH mice showed ethanol aversion. Their colonic microbiota differed markedly; amino acid metabolism fell, secondary bile acid synthesis rose, and SCFA production dropped in SWITCH + EtOH animals. Direct measurements confirmed significant reductions in butyrate, acetate, propionate, and selected amino acids. Network analysis revealed enrichment of bacterial metabolism, oxidative stress, and dopamine pathway genes.
Conclusions
Diet-induced dysbiosis, reflected in shifts in microbiota-derived metabolites, was associated with excessive alcohol intake; the metabolites identified can represent potential therapeutic targets for AUD.
New synthetic drugs, such as piperazines, cathinones, phenethylamines, and amphetamine derivatives have been widely used for recreational purposes, posing significant challenges for their preliminary identification in seized forensic samples. In this context, we present, for the first time, the use of a single electrochemical method for the screening of the four main classes of illicit stimulants found in seized tablet samples. The proposed approach is based on a simple and low-cost sensor using a graphite sheet modified by a cold oxygen-plasma treatment (GS-O2) with the differential pulse voltammetry (DPV) technique. The analytical performance of the proposed method was evaluated using thirteen stimulants commonly found in seized tablets, including the synthetic cathinones MDPV, alpha-PVP, ethylone, ephylone, dibutylone, and mephedrone (MEP); the amphetamines MDMA, MDA, and MDEA; the phenethylamines 2,5-dimethoxyphenethylamine (2C
H), and 4-Bromo-2,5-dimethoxyphenethylamine (2C-B); and the piperazines meta-chlorophenylpiperazine (mCPP) and benzylpiperazine (BZP). The proposed method demonstrated high reliability for selective discrimination between these four classes of drugs using both anodic and cathodic DPV scans. Furthermore, using MEP as a model analyte, a wide linear range (20 to 100 µmol L−1) and a low LOD (5 µmol L−1) were achieved. Additionally, the method was successfully applied to seven real seized tablet samples, which were confirmed by GC–MS. Therefore, the GS-O2 / DPV platform demonstrates to be a promising selective screening tool for amphetamines, synthetic cathinones, phenethylamines, and piperazines in forensic analysis, providing a rapid and simple discrimination of these drugs in seized tablet samples.
3D-printed electrochemical sensors have potential in several areas, including forensics. However, most proposed forensic electroanalytical approaches are not mass-produced, portable or user-friendly, which limit the dissemination of electrochemistry in this field. With the aim of spreading the use of electroanalysis in forensic sciences, we present in this work the Sensitive, Integrated, Mass-produced, Portable and Low-cost 3D-printed Electrochemical Sensing Set (SIMPLE-3D-SenS). This set consists of a miniaturized three-electrode sensor fabricated using a low-priced dual-extruder printer, a holder with a microliter-sized reservoir (ca. 250 µL) and a connector cable for rapid and easy assembly. After full characterization, the SIMPLE-3D-SenS demonstrated exceptional performance that was on par with or even superior to commercial glassy-carbon and screen-printed carbon electrodes. To demonstrate the ability of SIMPLE-3D-SenS to address contemporary forensic issues, it was explored for the detection of the opioid fentanyl. Under the best conditions, a linear concentration dependence was observed in the range of 0.10 until 9.10 µmol µmol L–1, and the limit of detection (LOD) was 0.017 µmol L–1. This LOD is close to the minimum lethal dose associated with fentanyl use, making SIMPLE-3D-SenS attractive for drug testing in biological fluids. Quantitative assays performed in synthetic urine showed good accuracy (recoveries between 103 % and 112 %). Additionally, SIMPLE-3D-SenS was utilized for the rapid screening of fentanyl in confiscated blotting paper samples, and the results agreed with those obtained by gas-chromatography. These results demonstrate the potentiality of this powerful and cutting-edge analytical tool, opening new avenues and possibilities for use in routine on-site forensic analyses.
The ongoing opioid crisis represents a critical global public health challenge, significantly impacting social outcomes and largely driven by widespread misuse and prolonged abuse. Codeine (COD) and morphine (MOR) are among the most consumed opioids worldwide. In this study, we propose a novel approach for the simultaneous detection of both compounds using additively manufactured electrodes (AMEs) composed of graphite, carbon black, and recycled poly(lactic) acid (Gpt-CB/rPLA). Prior to use, the AMEs underwent a chemical/electrochemical activation process in an alkaline medium (0.5 mol L−1 NaOH solution) to enhance their electrochemical performance, as confirmed through electrochemical characterization. Utilizing differential pulse voltammetry (DPV), we achieved linear detection ranges of 0.5–10.0 µmol L−1 for MOR and 1.0–10.0 µmol L−1 for COD, with limits of detection (LOD) of 0.05 and 0.07 µmol L−1 for MOR and COD, respectively. Additionally, recovery studies demonstrated excellent precision, with recovery values from approximately 81 % to 116 % when analyzing pharmaceutical and synthetic saliva samples.
The ongoing opioid crisis represents a critical global public health challenge, significantly impacting social outcomes and largely driven by widespread misuse and prolonged abuse. Codeine (COD) and morphine (MOR) are among the most consumed opioids worldwide. In this study, we propose a novel approach for the simultaneous detection of both compounds using additively manufactured electrodes (AMEs) composed of graphite, carbon black, and recycled poly(lactic) acid (Gpt-CB/rPLA). Prior to use, the AMEs underwent a chemical/electrochemical activation process in an alkaline medium (0.5 mol L−1 NaOH solution) to enhance their electrochemical performance, as confirmed through electrochemical characterization. Utilizing differential pulse voltammetry (DPV), we achieved linear detection ranges of 0.5–10.0 µmol L−1 for MOR and 1.0–10.0 µmol L−1 for COD, with limits of detection (LOD) of 0.05 and 0.07 µmol L−1 for MOR and COD, respectively. Additionally, recovery studies demonstrated excellent precision, with recovery values from approximately 81 % to 116 % when analyzing pharmaceutical and synthetic saliva samples.
The use of synthetic cathinones (SCs) has increased in recent years, posing significant public health problems due to their adverse effects and potential for fatal poisonings. The structural diversity and rapid emergence of new SC analogues create challenges for law enforcement and drug screening techniques. This work presents for the first time the electrochemical detection of SCs using differential pulse voltammetry (DPV) on a boron-doped diamond electrode (BDDE). We analyzed 15 SCs, including well-known compounds such as mephedrone, methylone, and ephylone, revealing distinct electrochemical profiles with two characteristic reduction peaks (R1 and R2). The method was optimized in Britton–Robinson buffer (0.1 mol L–1, pH 8.0) and demonstrated a high selectivity and sensitivity. Multivariate statistical methods, including principal component analysis and hierarchical cluster analysis, classified SCs into six distinct groups. The DPV optimization and analytical parameter determination, including the limit of detection (LOD), were performed for the least electroactive SC, 4′-methyl-α-pyrrolidinohexanophenone, yielding an LOD of 3.8 μmol L–1, suitable for screening street samples. Interference studies with common illicit drugs and adulterants confirmed the selectivity of the DPV-BDDE method. Preliminary identification of SCs in 46 real seized samples was successfully performed using this method with results validated by liquid chromatography–mass spectrometry (LC–MS). The method also identified three SCs not included in the original set: bupropion, benzylone, and dipentylone. The DPV-BDDE method offers a rapid, robust, and portable approach for the selective screening of SCs in forensic applications, demonstrating significant advantages over traditional colorimetric tests.
Background
Harmful use of alcohol (HUA) refers to drinking patterns that are associated with increased risk of medical complications and adverse social impacts. HUA is a multifactorial condition, involving neurotransmission system alterations, environmental factors, and genetic predisposition. Previous studies have identified numerous genetic variants associated with alcohol-related phenotypes. However, the generalizability of these findings remains limited, as most studies have primarily focused on European and Asian populations, leaving other ethnic groups, such as Latino Americans, underrepresented. Here, we explored the genetic mechanisms underlying HUA in admixed Brazilians. HUA was evaluated in 2,840 individuals using the Alcohol Use Disorder Identification Test (AUDIT). Genetic variations were assessed using a genome-wide genotyping array, followed by genotype imputation. Ancestry patterns were estimated by comparing individual variants with those of reference populations. Association analysis was performed using multivariate logistic regression, and the functional impacts of variants were investigated through in silico analysis. Pathway enrichment and network analyses were conducted to identify potential genetic mechanisms underlying HUA.
Results
Ancestry analysis confirmed the admixed nature of the study population, with lower levels of European ancestry significantly associated (p < 0.05, Mann-Whitney U test) with increased risk of HUA, suggesting potential ancestry-related genetic or socio-environmental factors contributing to alcohol-related behaviors. The genome-wide association study identified a significant association between the variant rs1097611 at 1p33 and HUA p = 4.88 × 10-8, odds ratio [OR] = 1.8, confidence interval [CI] = 1.46–2.23), based on a multivariate logistic regression model assuming additive genetic effects and adjusted for sex and European ancestry. The rs1097611 and other variants at this locus are located in regulatory regions and have been previously associated with differential CYP4B1 expression across multiple tissues. Other suggestive association signals (5 × 10-8 < p < 10− 5) were identified at loci previously implicated in addictive substance use behaviors, including alcohol and/or tobacco consumption, such as 10q21.2 (ARID5B), 5q34-q35.1 (SLIT3), and 10q11.23 (SGMS1). Genome-based pathway enrichment analysis revealed several mechanisms potentially involved in HUA, primarily related to neurobiological processes and neuronal signaling. Finally, network analysis revealed a highly interconnected cluster of nervous system-related pathways, pointing to their potential functional interplay.
Conclusions
This study identifies novel loci, particularly at 1p33 (CYP4B1), and genetic mechanisms potentially involved in HUA in an admixed Latin American population. Studies in diverse ethnic groups are crucial to uncover novel genetic risk variants for HUA and improve its management.
Minoxidil (MN) is a vasodilator used to treat hair loss and severe hypertension. However, its illegal use in cosmetics and pharmaceutical formulations has been reported in several countries. An efficient method for MN detection is of great interest for forensic and pharmaceutical applications. Electrochemical sensors have been reported as an interesting alternative for MN detection in various samples. However, a more in-depth study of the redox processes and a more selective electrochemical detection for MN are still required. In this context, we present, for the first time, the use of nuclear magnetic resonance and Fourier transform infrared spectroscopy analyses for understanding the electrochemical behaviour of MN after electrolysis procedures on a boron-doped diamond electrode (BDDE). Using these combined techniques, we have proposed and confirmed an electrochemical mechanism for all redox processes of MN on a BDDE, where in phosphate buffer (pH 6.0) two oxidation processes at +0.72 V and +0.97 V vs (Ag/AgCl/ sat. KCl) are presented. The last generated product by MN oxidation is reduced on the BDDE surface at -0.01 V with a quasi-reversible redox process. The use of this redox process is the strategy for a selective and sensitive detection of MN on the BDDE. This innovative approach was successfully applied to determine MN in adulterated cosmetics and pharmaceutical formulations, showing a low limit of detection (5.7 µmol. L-1) and high stability of electrochemical responses (RSD < 1.5 %, n = 6) using the same BDDE. Therefore, the proposed method provides a simple, fast and selective method for the identification and quantification of MN in pharmaceutical and forensic samples.
Minoxidil (MN) is a vasodilator used to treat hair loss and severe hypertension. However, its illegal use in cosmetics and pharmaceutical formulations has been reported in several countries. An efficient method for MN detection is of great interest for forensic and pharmaceutical applications. Electrochemical sensors have been reported as an interesting alternative for MN detection in various samples. However, a more in-depth study of the redox processes and a more selective electrochemical detection for MN are still required. In this context, we present, for the first time, the use of nuclear magnetic resonance and Fourier transform infrared spectroscopy analyses for understanding the electrochemical behaviour of MN after electrolysis procedures on a boron-doped diamond electrode (BDDE). Using these combined techniques, we have proposed and confirmed an electrochemical mechanism for all redox processes of MN on a BDDE, where in phosphate buffer (pH 6.0) two oxidation processes at +0.72 V and +0.97 V vs (Ag/AgCl/ sat. KCl) are presented. The last generated product by MN oxidation is reduced on the BDDE surface at -0.01 V with a quasi-reversible redox process. The use of this redox process is the strategy for a selective and sensitive detection of MN on the BDDE. This innovative approach was successfully applied to determine MN in adulterated cosmetics and pharmaceutical formulations, showing a low limit of detection (5.7 µmol. L-1) and high stability of electrochemical responses (RSD < 1.5 %, n = 6) using the same BDDE. Therefore, the proposed method provides a simple, fast and selective method for the identification and quantification of MN in pharmaceutical and forensic samples.
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