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Previous research has evaluated the extent to which cocaine and other drugs were detectable on currency in the USA. The literature was in agreement that the majority of bills exhibited some degree of contamination. With the increase of fentanyl in the illicit drug supply, this study was designed to evaluate the extent that fentanyl, cocaine, methamphetamine and other substances were present on circulating currency in 2022. A quantitative assay using liquid chromatography-triple quadrupole mass spectrometry was developed and validated to detect six analytes: fentanyl, 4-anilino-N-phenethylpiperidine, acetylfentanyl, benzylfentanyl, cocaine and methamphetamine. One-dollar bills were collected from 13 cities across the country. Sample preparation consisted of soaking the bills in methanol followed by liquid-liquid extraction. Chromatographic separation was achieved using a C18 analytical column and gradient elution with ammonium formate in water (5 mM, pH 3) and 0.1% formic acid in acetonitrile. The quantitative working range for this assay was 0.1 μg to 1.0 μg per bill (equivalent to 1 ng/mL to 100 ng/mL of extract). Fentanyl was detected on the majority (63%) of samples, with 61% of samples having ≥0.1 μg of fentanyl and 4% of samples having ≥1.0 μg. Cocaine and methamphetamine were detected on 100% and 98% of bills, respectively, typically in amounts >1.0 μg. The remaining fentanyl-related substances were detected in 15% of samples in amounts no >0.69 μg per bill and exclusively in the presence of fentanyl. Unsurprisingly, areas of the country with higher incidence of fentanyl use yielded higher frequency of contaminated bills and higher concentrations. Human exposure to drugs on currency is unlikely to have any significant impacts toxicologically or pharmacologically; however, our research findings suggest that paper currency could serve as a useful substrate for surveillance of drug trends regionally, nationally and/or internationally., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site–for further information please contact journals.permissions@oup.com.)

The need for providing rapid and, possibly, on-the-spot analytical results in the case of intoxication has prompted researchers to develop rapid, sensitive, and cost-effective methods and analytical devices suitable for use in nonspecialized laboratories and at the point of need (PON). In recent years, the technology of paper-based microfluidic analytical devices (μPADs) has undergone rapid development and now provides a feasible, low-cost alternative to traditional rapid tests for detecting harmful compounds. In fact, µPADs have been developed to detect toxic molecules (arsenic, cyanide, ethanol, and nitrite), drugs, and drugs of abuse (benzodiazepines, cathinones, cocaine, fentanyl, ketamine, MDMA, morphine, synthetic cannabinoids, tetrahydrocannabinol, and xylazine), and also psychoactive substances used for drug-facilitated crimes (flunitrazepam, gamma-hydroxybutyric acid (GHB), ketamine, metamizole, midazolam, and scopolamine). The present report critically evaluates the recent developments in paper-based devices, particularly in detection methods, and how these new analytical tools have been tested in forensic and clinical toxicology, also including future perspectives on their application, such as multisensing paper-based devices, microfluidic paper-based separation, and wearable paper-based sensors.

Illicit drug trafficking and abuse is a significant public safety and health concern. Color tests are commonly used for drug screening, but their poor specificity results in false positives. This study demonstrates the combination of drug residue collection using pressure-sensitive adhesive paper, on-paper color testing, and post-reaction analysis by paper spray mass spectrometry (PS-MS) on both portable and benchtop ion trap MS. All steps, including residue collection, color testing, and paper spray analysis, were performed on the same piece of paper. Three common color tests were investigated: the cobalt thiocyanate test for cocaine, the Simon test for methamphetamine, and the Marquis test for phenethylamine stimulants and opiates. The detection threshold for color tests ranged from 1.25 to 10 μg on paper. Drug residues were successfully confirmed by paper spray MS at the color test threshold in all cases, except for heroin after reaction with the Marquis reagent, when using the portable MS. In this case, the MS detection threshold was 4-fold higher than the color test threshold. The stability of the color test products was assessed through a time study. Drug residues could be detected by MS at least 24 hours after reaction. A series of realistic samples, including false positives, were analyzed to demonstrate the technique's utility in real-world scenarios. Overall, combining color tests with PS-MS offers a rapid, low-cost method for the collection and analysis of illicit drugs.

It is well established that a large proportion of paper banknotes in circulation contain traces of cocaine. Being able to discriminate between the innocent transfer of illicit drug particles acquired through everyday interactions with surfaces such as banknotes, as opposed to transfer resulting from criminal activities can provide valuable intelligence that can inform an investigation. With many countries adopting polymer banknotes as legal tender, it is important to consider the transfer of cocaine from these surfaces as well as the retention of these particulates on polymer banknotes for evaluative interpretation in crime reconstruction. This comparison study assessed three contact variables (force, time, and rotation) on the transfer of cocaine particulates from paper and polymer banknotes onto a human skin proxy. The persistence of cocaine particulates was assessed through a realistic scenario which mimicked a cash transaction. Quantifiable amounts of cocaine were transferred onto the human skin proxy across all of the contacts assessed, with a greater transfer observed with contacts involving polymer banknotes and those contacts which involved rotation. Following extensive handling, cocaine persisted on both banknote types, with paper banknotes retaining larger amounts of cocaine than polymer banknotes. These findings show that cocaine can persist on both paper and polymer banknotes for extended periods of time following handling and is therefore available for transfer. This transfer then readily occurs, even when contact is brief and involves relatively small forces. A key distinction between the banknote types was that cocaine particulates are more likely to transfer from polymer banknotes due to the lower retention rate of particulates on this surface. Such insights can aid in evaluating the relevance of illicit drug particles identified on items or persons of interest in crime reconstruction approaches., (Copyright © 2022 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.)

Molecularly imprinted polymers are efficient and selective adsorbents which act as artificial receptors for desired compounds with the ability to recognize the size, shape, and functional groups of the compounds simultaneously. A molecularly imprinted polymer is prepared by the polymerization of functional monomers around a template (analyte) molecule. Afterward, the removal of the template from the polymer matrix leaves a selective cavity behind. The fabrication and development of molecularly imprinted polymers grew rapidly, due to their low cost, simple preparation, selectivity, sensitivity, and stable physicochemical properties. Traditionally, molecularly imprinted polymers can be synthesized using two main methods, namely bulk and surface imprinting. For more efficient use of the latter method, researchers have developed molecularly imprinted polymers grafted on the solid-phase matrix (substrate). This grafting technique would be particularly useful for surface imprinting of macromolecules, such as proteins. Cellulose fibers of papers with unique properties such as being abundant, retaining a porous structure, having good adsorption properties, and possessing hydroxyl groups naturally have gained much attention as substrate. The goal of this review is to introduce molecularly imprinted polymer-grafted or molecularly imprinted polymer-coated paper, as an interesting, simple, and efficient method in the detection and separation of small and large molecules. Therefore, in the present paper, several recent preparation techniques and applications of molecularly imprinted polymer-grafted paper are reviewed and discussed in detail. Green, cost-effective, selective, and sensitive paper-based sensor prepared via grafting molecularly imprinted polymer on paper surface with the potential use for online detection trace of analytes in the point-of-care testing., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

In this note we describe a four-channel paper microfluidic device (μPAD) that utilizes gold nanoparticles (AuNPs) as colorimetric sensors and specifically tailored aptamers to capture a set of targeted drugs, including cocaine, codeine and methamphetamine. The design utilizes salt-induced aggregation of AuNPs to produce a color change that indicates the presence of target analytes. In the absence of the targets, the aptamers bind to AuNPs, preventing aggregation. This μPAD was developed by optimizing the concentrations of aggregating agents, AuNPs and aptamers. The resultant device is sensitive and specific, producing a positive result upon detection of the target analyte., Competing Interests: Declaration of competing interest The authors have declared no conflict of interest., (Copyright © 2020. Published by Elsevier Inc.)

Paper spray mass spectrometry (PS-MS) has been shown to be a rapid, simple and inexpensive alternative to traditional forensic drug screening methods. It can address the limitations of both immunoassays and chromatography-based techniques due to its non-reliance on sample preparation and its ability to rapidly screen for a wide array of compounds. In this study, an automated PS-MS system was employed to semi-quantitatively screen for 40 commonly abused drugs and metabolites in urine after a 15-min glucuronidase reaction. The target compounds included common prescription opioids, fentanyl and norfentanyl, stimulants including methamphetamine and cocaine, benzodiazepines and antidepressants. The enzyme, buffer and internal standard solution were combined in one spiking solution to minimize sample handling. Analysis was carried out using a commercially available automated paper spray system coupled to a triple quadrupole mass spectrometer. This method may prove useful for clinical and forensic toxicology laboratories as it allows for automated screening of complex samples for drugs without extraction, separation and sample cleanup., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Dry-state microsampling techniques are convenient and advantageous for sample collection in resource-limited settings, including healthcare systems designed for the underserved population. In this work, a microsampling platform based on an embossed hydrophobic paper substrate is introduced together with three-dimensional (3D) printed cartridges that offer opportunities for rapid (<30 min) drying of the collected samples while also preserving sample integrity when the embossed paper chip is shipped at room temperature. More importantly, a new pinhole paper spray ionization method was developed that facilitates direct mass spectrometry (MS) analysis of the dried blood samples without prior sample preparation. We compared the direct pinhole paper spray MS method with a liquid chromatographic (LC) MS approach that relied upon electrospray ionization (ESI) after analytes present in the blood sample were extracted through liquid-liquid extraction. Limits of detection as low as 0.12 and 0.49 ng/mL were calculated for cocaine and its metabolite benzoylecgonine, respectively, when using the direct pinhole paper spray MS method. Analytical merits such as precision and accuracy, recovery, carryover effects, and analyte stability were all quantified for this new paper spray method and compared to the traditional LC-ESI-MS. Although LC-ESI-MS was observed to be 10× more sensitive, the linear dynamic range for both methods was determined to be the same, in the range of 1-500 ng/mL for both cocaine and benzoylecgonine analytes. When fully developed, the current microsampling strategy could offer an easy-to-use kit that can enable a more effective MS analysis of 20 μL dried blood samples delivered by mail. Both sensitivity (10×) and sample stability are found to be more superior for blood prepared in the embossed hydrophobic paper compared to samples prepared in the planar hydrophilic paper.

Natural and synthetic alkaloids are widely used for several applications, ranging from clinical purposes to criminal activities. Presumptive color tests are considered a leading tool to reveal on-scene substance identification via rapid chemical reactions that result in visual color changes. Colorimetric tests are popular due to their inherent simplicity, low cost, promptitude and portability; however, in many cases the results of such tests may not be predictable, partly because of the interference from similar species. In this proof-of-concept study, we present a paper-based microfluidic optoelectronic tongue - the so-called μOPTO - comprised of 6 indicators in lieu of one specific test and capable of discriminating 8 different alkaloid drugs (i.e. scopolamine, atropine, cocaine, morphine, ephedrine, caffeine, dipyrone and alprazolam) used for recreational, criminal and medical purposes. The wax printing method was employed to fabricate the microfluidic analytical device with six circular spots for reagent accommodation connected to a centered spot to enable simultaneous reactions with one sample injection. Digital images were obtained using an ordinary flatbed scanner, and the RGB information from before and after sample exposure was extracted using appropriate software. The color changes related to each spot were used to build differential maps with a unique fingerprint for each drug. The chemometric tools (i.e. PCA and HCA) showed suitable discrimination of all studied alkaloids in different quantities. To demonstrate a practical application, different alcoholic beverages spiked with scopolamine - a famous substance that causes drug abuse - were analyzed using the optoelectronic tongue. The results showed that small quantities of the drug were identified in different beverages, demonstrating that our device has the potential to be used in situ to prevent ingestion of contaminated samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

An office paper-based colorimetric device is proposed as a portable, rapid, and low-cost sensor for forensic applications aiming to detect phenacetin used as adulterant in illicit seized materials such as cocaine. The proposed method uses white office paper as the substrate and wax printing technology to fabricate the detection zones. Based on the optimum conditions, a linear analytical curve was obtained for phenacetin concentrations ranging from 0 to 64.52µgmL ‒1 , and the straight line was in accordance with the following equation: (Magenta percentage color) = 1.19 + 0.458 (C Phe /µgmL ‒1 ), R 2 = 0.990. The limit of detection was calculated as 3.5µgmL ‒1 (3σ/slope). The accuracy of the proposed method was evaluated using real seized cocaine samples and the spike-recovery procedure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study proposes a new direct and fast method of analysis employing paper spray mass spectrometry (PS-MS). The paper used in the proposed method was modified with molecularly imprinted polymers (MIP) to create a specific site for cocaine analysis in oral fluid. MIP membrane was successfully synthetized and employed. The developed method showed to be linear in a concentration range from LOQ to 100 ng mL -1 . The experimental value of LOQ obtained was 1 ng mL -1 . The inter-day and intra-day precision and accuracy of the PS-MS method presented values lower than 15%. The total recoveries were also evaluated. The PS-MS method for the analysis of cocaine in oral fluid showed to be very promising and the validation parameters showed a good correlation with the literature. Graphical abstract ᅟ.

Paper based microfluidics (µPADs) with advantages of portability, low cost, and ease of use have attracted extensive attention. Here we describe a novel method that integrates glucoamylase-trapped aptamer-crosslinked hydrogel for molecular recognition with cascaded enzymatic reactions for signal amplification and a µPAD for portable readout. Upon target introduction, the hydrogel decomposes to release glucoamylase, which catalyzes the hydrolysis of amylose to produce a large amount of glucose. With a simple folding of the µPAD, the sample solution containing glucose product wicks and diffuses in parallel to each test-zone to carry out homogeneous assays, where glucose is used to produce I2 for brown color visualization through multiple enzymatic and chemical cascade reactions. Through color gradient changes based on different concentrations of the target, a semiquantitative assay is achieved by the naked eye, and quantitation can be obtained by handheld devices. Detection of cocaine in buffer and urine was performed to demonstrate the utility of the hydrogel-µPAD system. More importantly, the hydrogel-µPAD system can be extended to the detection of various targets by incorporating the corresponding aptamer into the hydrogel. The hydrogel-µPAD system reported here provides a new platform for portable, disposable and visual detection of a wide range of targets., (Copyright © 2015 Elsevier B.V. All rights reserved.)

We report the first portable upconversion nanoparticles (UCNPs)-based paper device for road-side field testing of cocaine. Upon the recognition of cocaine by two pieces of rationally designed aptamer fragments, the luminescence of UCNPs immobilized on the paper is quenched by Au nanoparticles (AuNPs), which indicates the cocaine concentration. This device can give quantitative results in a short time with high sensitivity using only a smartphone as the apparatus. Moreover, this device is applicable in human saliva samples, and it also can be used to monitor the cocaine content change in blood samples. The results of this work demonstrate the prospect of developing UCNPs-based paper devices for field testing of drug abuse.

A versatile point-of-care assay platform was developed for simultaneous detection of multiple targets based on a microfluidic paper-based analytic device (μPAD) using a target-responsive hydrogel to mediate fluidic flow and signal readout. An aptamer-cross-linked hydrogel was used as a target-responsive flow regulator in the μPAD. In the absence of a target, the hydrogel is formed in the flow channel, stopping the flow in the μPAD and preventing the colored indicator from traveling to the final observation spot, thus yielding a "signal off" readout. In contrast, in the presence of a target, no hydrogel is formed because of the preferential interaction of target and aptamer. This allows free fluidic flow in the μPAD, carrying the indicator to the observation spot and producing a "signal on" readout. The device is inexpensive to fabricate, easy to use, and disposable after detection. Testing results can be obtained within 6 min by the naked eye via a simple loading operation without the need for any auxiliary equipment. Multiple targets, including cocaine, adenosine, and Pb(2+), can be detected simultaneously, even in complex biological matrices such as urine. The reported method offers simple, low cost, rapid, user-friendly, point-of-care testing, which will be useful in many applications.

Background: Paper spray mass spectrometry (PS-MS) is a technique that has recently emerged and has shown excellent analytical sensitivity to a number of drugs in blood. As an alternative to blood, fingerprints have been shown to provide a noninvasive and traceable sampling matrix. Our goal was to validate the use of fingerprint samples to detect cocaine use., Methods: Samples were collected on triangular pieces (168 mm 2 ) of washed Whatman Grade I chromatography paper. Following application of internal standard, spray solvent and a voltage were applied to the paper before mass spectrometry detection. A fingerprint visualization step was incorporated into the analysis procedure by addition of silver nitrate solution and exposing the sample to ultraviolet light., Results: Limits of detection for cocaine, benzoylecgonine, and methylecgonine were 1, 2, and 31 ng/mL respectively, with relative standard deviations < 33%. No matrix effects were observed. Analysis of 239 fingerprint samples yielded a 99% true-positive rate and a 2.5% false-positive rate, based on the detection of cocaine, benzoylecgonine, or methylecgonine with use of a single fingerprint., Conclusions: The method offers a qualitative and noninvasive screening test for cocaine use. The analysis method developed is rapid (4 min/sample) and requires no sample preparation., (© 2017 American Association for Clinical Chemistry.)

We demonstrate a paper-based surface swab and lateral-flow dipstick that includes an inkjet-printed surface-enhanced Raman spectroscopy (SERS) substrate for analyte detection. Due to capillary-action wicking of cellulose, the paper dipstick enables extremely simple and pump-free loading of liquid samples into the detection device, and in addition provides inherent analyte concentration within the detection volume. Furthermore, the flexible nature of the paper-based SERS device also enables it to act as a swab to collect analyte molecules directly from a large-area surface; the collected analyte molecules can then be focused into a small-volume SERS-active region by lateral-flow concentration. These capabilities are unseen in today's SERS substrates and microfluidic SERS devices. Using these novel lateral-flow paper SERS devices, we achieved detection limits as low as 95 fg of Rhodamine 6G (R6G), 413 pg of the organophosphate malathion, 9 ng of heroin, and 15 ng of cocaine. Moreover, the measurements show that the technique is quantitative and is repeatable across multiple swabs and dipsticks. The results reported here may lead to ultra-low-cost portable applications in trace chemical detection.

A method utilizing paper microfluidics coupled with gold nanoparticles and two anticocaine aptamers has been developed to detect seized cocaine samples. The ready-to-use format involves the use of a paper strip that produces a color change resulting from the salt-induced aggregation of gold nanoparticles producing a visible color change indicating the presence of the drug. This format is specific for the detection of cocaine. The visual LOD for the method was 2.5 μg and the camera based LOD was 2.36 μg. The operation of the device is easy and rapid, and does not require extensive training or instrumentation. All of the materials utilized in the device are safe and environmental friendly. This device should prove a useful tool for the screening of forensic samples., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The presence of cocaine on US paper currency has been known for a long time. Banknotes become contaminated during the exchange, storage, and abuse of cocaine. The analysis of cocaine on various denominations of US banknotes in the general circulation can provide law enforcement circles and forensic epidemiologists objective and timely information on epidemiology of illicit drug use and on how to differentiate money contaminated in the general circulation from banknotes used in drug transaction. A simple, nondestructive, and accurate capillary gas chromatographic method has been developed for the determination of cocaine on various denominations of US banknotes in this study. The method comprises a fast ultrasonic extraction using water as a solvent followed by a SPE cleanup process with a C(18) cartridge and capillary GC separation, identification, and quantification. This nondestructive analytical method has been successfully applied to determine the cocaine contamination in US paper currency of all denominations. Standard calibration curve was linear over the concentration range from the LOQ (2.00 ng/mL) to 100 microg/mL and the RSD less than 2.0%. Cocaine was detected in 67% of the circulated banknotes collected in Southeastern Massachusetts in amounts ranging from approximately 2 ng to 49.4 microg per note. On average, $5, 10, 20, and 50 denominations contain higher amounts of cocaine than $1 and 100 denominations of US banknotes.

Several studies have reported on wide-spread contamination of U.S. paper currency with cocaine and to a lesser extent other illicit drugs. Canines are trained and employed to search for and alert to drugs. Canine alert to currency has been used as evidence that currency has been directly involved in illicit drug trafficking to justify currency seizure and forfeiture. This assertion, particularly when the only evidence is based upon canine alert, has been challenged in the courts considering that most currency in circulation is contaminated with cocaine. Comprehensive review of the scientific literature establishes that (i) 67-100% of circulated U.S. currency is contaminated with cocaine ranging from a few nanograms to over one milligram/bill (ii) various biological and environmental parameters impact canine alert to drugs. It is concluded that canine alert to U.S. currency is not sufficiently reliable to determine that currency was directly used in an illicit drug transaction.

Laboratory experiments were developed to introduce students to the quantitation of drugs of abuse by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Undergraduate students were introduced to internal standard quantitation and the LC-MS/MS method optimization for cocaine. Cocaine extracted from paper currency was analyzed with a simple and rapid LC-MS/MS method. Students in advanced laboratories determined the amount of amphetamine, methamphetamine, and oxycodone on currency in addition to cocaine. The LC-MS/MS method has a short run time (2.5 min) to allow for a high throughput of student samples.

Solid-phase microextraction (SPME) combined with gas chromatography (GC) is optimized and applied to the analysis of street-cocaine samples followed by the field-testing of isolated chemicals using certified detector dogs. SPME proves to be a very sensitive and rapid method for isolating odor chemicals from street-cocaine samples. SPME-GC and activated charcoal strip (ACS)-SPME-GC signature profile methods are developed for the detection and quantitation of cocaine-odor chemicals, including the optimization of controllable variables such as fiber chemistry, extraction time, and desorption time. The volatile odor chemicals in representative illicit cocaine samples are identified and quantitated by the ACS-SPME-GC signature profile method and direct injection. Field tests with drug detector dogs show methyl benzoate to be the dominant signature odor chemical along with cocaine on U.S. currency at a threshold level of approximately 1-10 microg when spiked or when 10 ng/s methyl benzoate is diffused from polymer bottles, which is required in order to initiate an alert. No other substance studied initiated consistent responses by the drug dogs. The results indicate that the microgram levels of cocaine that have been reported on circulated U.S. currency are insufficient to signal an alert from law-enforcement trained drug detector dogs.

Background: The analysis of drug traces on banknotes with different validated techniques can provide important information about the types of substances that are used in a geographical region. The aim of our review was to investigate banknotes' contamination by cocaine, by its metabolite, but also by other drugs., Methods: A systematic literature search (English written literature) was conducted in MEDLINE, and Scopus, collecting studies from 1974 till 2017. The Key search terms included: 'banknote AND drug'; 'banknote AND cocaine'., Results: The literature search yielded 88 publications; 9 were included in our review. In six studies that showed banknotes' positivity to cocaine, the percentage ranged from 2.5% to 100%. The concentration of cocaine ranged from 0.09 ng/note to 889 µg/note. Benzoylecgonine was indentified only in three studies with a range from 0.71 to 130 ng/note. Other indentified drugs were: amphetamine derivatives, opiates, benzodiazepines., Conclusions: Circulating banknotes could be used to indicate substances used in a population, and those recently introduced in a geographical macro-area. The identification of very high amounts of cocaine can provide important information for the identification of banknotes used in illegal trafficking., (© The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.)

This study focused on quantitative detection of cocaine on Euro banknotes in Germany. A sensitive direct competitive immunoassay was developed and optimized with a limit of detection (LOD) of 5.6ng/L. Exhaustive cocaine extraction by solvent was tested using different methanol concentrations and buffered solutions. Cross-reactivity studies were performed to determine the degree of interference of cocaine metabolites with the immunoassay. Sixty-five Euro banknotes obtained from different districts in Berlin were evaluated. A 100% contamination frequency with cocaine was detected. A comparison between the amount of cocaine extracted by cotton swabbing of one square centimeter of the banknote showed a good correlation for lower contamination levels. This assay showed high sensitivity of detecting pg of cocaine per 1cm 2 of one banknote by swabbing 1cm 2 : 0, 14, and 21pg/cm 2 . Moreover, three notes of different denominations revealed high cocaine concentration; 1.1mg/note, and twice 55µg/note., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A study of the quantities of cocaine on banknotes in general circulation was conducted to investigate regional variations across England and Wales. No meaningful support was found for the proposition that there is regional variation in the quantities of cocaine in banknotes in general circulation in England and Wales., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0μgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Previous studies have shown that drug concentrations in blood can change during storage, especially at room temperature, but even labile drugs such as cocaine may be stable in dried blood spots (DBS). A new method has been developed for the analysis of hydrolytically labile drugs in blood spots on filter paper in order to assess their degradation during a storage period of one month. The drugs selected included flunitrazepam, temazepam, oxazepam, lorazepam, nitrazepam, diazepam, and cocaine. A Guthrie card 903 was spotted with 100 microL of blood containing the drugs at concentrations of 1000 ng/mL and left overnight to dry at room temperature. The filter paper was suspended in extraction buffer for 1 h with ultrasonication. Drugs were then extracted from the buffer by solid-phase extraction using Clean Screen((R)) columns and analyzed by liquid chromatography-tandem mass spectrometry. Method validation showed that all calibration curves were linear over the concentration range 5-200 ng/spot with correlation coefficients of 0.994-0.999. Interday and intraday precisions at three concentrations (10, 50, and 100 ng/spot) were 1.6-18.3% and 2.8-14.7%, respectively. Limits of detection were 0.29-0.74 ng/spot, and lower limits of quantitation were 0.99-2.46 ng/spot. Recoveries of all analytes were in the range 81-106%. DBS were stored in duplicate at room temperature, 4 degrees C, and -20 degrees C for up to one month. Degradation of the drugs in DBS at all storage conditions was less than for the corresponding liquid blood samples stored under similar conditions and more than 80% of each analyte could be recovered from the samples.

This paper shows the result of a study on the extent of cocaine contamination in Real banknotes in circulation in the state of Rio de Janeiro (Brazil). A study of the percentage of contaminated banknotes was made, as well as a study on the contamination of banknotes based on different values, and a study of contamination depending on the region where the banknote was collected. The idea of this last study was to verify if the peculiar characteristics of the region of study (in particular, the city of Rio de Janeiro) influence the amount of cocaine in the banknotes. Some regions have higher consumption/drug trafficking of cocaine than others. Also, some contaminated banknotes confiscated directly from drug dealers and users were analyzed. Also, is showed in this paper all the optimization of the available analytical techniques for making the measurements possible., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

A sensitive and versatile competitive enzyme immunoassay (cEIA) has been developed for the quantitative detection of cocaine in complex forensic samples. Polyclonal anti-cocaine antibody was purified from serum and deposited onto microtiter plates. The concentration of the cocaine antibody adsorbed onto the plates, and the dilution of the cocaine-HRP hapten were both studied to achieve an optimised immunoassay. The method was successfully used to quantify cocaine in extracts taken from both paper currency and latent fingermarks. The limit of detection (LOD) of 0.162ngmL(-1) achieved with the assay compares favourably to that of conventional chromatography-mass spectroscopy techniques, with an appropriate sensitivity for the quantification of cocaine at the low concentrations present in some forensic samples. The cEIA was directly compared to LC-MS for the analysis of ten UK banknote samples. The results obtained from both techniques were statistically similar, suggesting that the immunoassay was unaffected by cross-reactivity with potentially interfering compounds. The cEIA was used also for the detection of cocaine in extracts from latent fingermarks. The results obtained were compared to the cocaine concentrations detected in oral fluid sampled from the same individual. Using the cEIA, we have shown, for the first time, that endogeneously excreted cocaine can be detected and quantified from a single latent fingermark. Additionally, it has been shown that the presence of cocaine, at similar concentrations, in more than one latent fingermark from the same individual can be linked with those concentrations found in oral fluid. These results show that detection of drugs in latent fingermarks could directly indicate whether an individual has consumed the drug. The specificity and feasibility of measuring low concentrations of cocaine in complex forensic samples demonstrate the effectiveness and robustness of the assay. The immunoassay presents a simple and cost-effective alternative to the current mass spectrometry based techniques for the quantitation of cocaine at forensically significant concentrations., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

The exchange of illicit cocaine for money by drug dealers is an everyday occurrence in cities in the United States. There is ample opportunity during the exchange, storage, and use of cocaine for paper currency to become contaminated. Because currency is exchanged frequently, it is likely that contaminated currency would be found in common use. We examined ten single dollar bills from several cities in the United States for the presence of cocaine. Individual bills were extracted with methanol (10 mL). Cocaine was purified from the methanol extract by solid-phase extraction (SPE). The SPE extract was analyzed by gas chromatography-mass spectrometry (GC-MS). Standard curves were constructed with new, uncirculated currency. Cocaine was identified qualitatively by full scan and quantitated by selected ion monitoring. Cocaine was present in 79% of the currency samples analyzed in amounts above 0.1 micrograms and in 54% of the currency in amounts above 1.0 micrograms. Contamination was widespread and was found in currency from all sites examined. Cocaine amounts were highly variable and ranged from nanogram to milligram amounts. The highest amount of cocaine detected on a single one-dollar bill was 1327 micrograms. These results indicated that cocaine contamination of currency is widespread throughout the United States and is likely to be primarily a result of cross-contamination from other contaminated currency and from contaminated money-counting machines.

In this paper, a novel approach based on paper spray ionization coupled with ion mobility spectrometry (PSI-IMS) was developed for rapid, in situ detection of cocaine residues in liquid samples and on various surfaces (e.g. glass, marble, skin, wood, fingernails), without tedious sample pretreatment. The obvious advantages of PSI are its low cost, easy operation and simple configuration without using nebulizing gas or discharge gas. Compared with mass spectrometry, ion mobility spectrometry (IMS) takes advantage of its low cost, easy operation, and simple configuration without requiring a vacuum system. Therefore, IMS is a more congruous detection method for PSI in the case of rapid, in situ analysis. For the analysis of cocaine residues in liquid samples, dynamic responses from 5 μg mL(-1) to 200 μg mL(-1) with a linear coefficient (R(2)) of 0.992 were obtained. In this case, the limit of detection (LOD) was calculated to be 2 μg mL(-1) as signal to noise (S/N) was 3 with a relative standard deviation (RSD) of 6.5% for 11 measurements (n = 11). Cocaine residues on various surfaces such as metal, glass, marble, wood, skin, and fingernails were also directly analyzed before wiping the surfaces with a piece of paper. The LOD was calculated to be as low as 5 ng (S/N = 3, RSD = 6.3%, n = 11). This demonstrates the capability of the PSI-IMS method for direct detection of cocaine residues at scenes of cocaine administration. Our results show that PSI-IMS is a simple, sensitive, rapid and economical method for in situ detection of this illicit drug, which could help governments to combat drug abuse.

In the context of modern society, the persistent challenge of narcotic drug trafficking and abuse remains a significant concern, profoundly impacting social adeptness and cognitive well-being. This study aims to devise innovative tools to mitigate the illicit movement of narcotic drugs across borders. Our approach utilises specific antibodies targeting cocaine antigens as the sensing element in a biosensor design. Employing an immunoassay framework, we operationalise an indirect ELISA based methodology, wherein cocaine antigens are immobilised onto a membrane and antibodies conjugated with Horse Radish Peroxidase (HRP) are introduced. Successful binding of the antibody to the antigen occurs exclusively in the presence of cocaine, leading to a colourimetric response whose intensity correlates with the cocaine concentration. Validation of this colour change is achieved through software analysis using ImageJ software. While our study focuses on qualitative analysis, our methodology paves the way for future quantitative assessments through dedicated reading devices. [ABSTRACT FROM AUTHOR]

A novel electrochemiluminescence (ECL) "sandwich" biosensor has been developed to detect cocaine. The sandwich biosensor was fabricated on the basis of the fact that a single aptamer could be split into two fragments and the two dissociated parts could form a folded, associated complex in the presence of targets. One of these (capture probe), which had hexane-thiol at its 5'-terminus, was immobilized on a gold electrode via thiol-gold binding. The other one (detection probe) was labeled with the ECL reagent tris(2,2'-bipyridyl)ruthenium(II)-doped silica nanoparticles (RuSiNPs) at its 3'-terminus. Owing to the weak interaction between the two fragments, the sensor exhibited a low ECL signal in the absence of cocaine. After the target cocaine had been added to the solution, it induced association of the two fragments and stabilized the associated complexes, leading to immobilization of RuSiNPs on the electrode surface, and the ECL detected on the electrode surface was enhanced. The enhanced ECL intensity was directly proportional to the logarithm of the cocaine concentration in the range from 1.0 × 10(-9) to 1.0 × 10(-11) mol/L, with a detection limit of 3.7 × 10(-12) mol/L. The biosensor was applied to detect trace amounts of cocaine on banknotes with satisfactory results.

Capillary electrophoresis (CE) with Ru(bpy)3(2+) electrochemiluminescence (ECL) detection system was established to the determination of contamination of banknotes with controlled drugs and a high efficiency on-column field-amplified sample stacking (FASS) technique was also optimized to increase the ECL intensity. The method was illustrated using heroin and cocaine, which are two typical and popular illicit drugs. Highest sample stacking was obtained when 0.01 mM acetic acid was chosen for sample dissolution with electrokinetical injection for 6 s at 17 kV. Under the optimized conditions: ECL detection at 1.2 V, separation voltage 10.0 kV, 20 mM phosphate-acetate (pH 7.2) as running buffer, 5 mM Ru(bpy)3(2+) with 50 mM phosphate-acetate (pH 7.2) in the detection cell, the standard curves were linear in the range of 7.50x10(-8) to 1.00x10(-5) M for heroin and 2.50x10(-7) to 1.00x10(-4) M for cocaine and detection limits of 50 nM for heroin and 60 nM for cocaine were achieved (S/N = 3), respectively. Relative standard derivations of the ECL intensity and the migration time were 3.50 and 0.51% for heroin and 4.44 and 0.12% for cocaine, respectively. The developed method was successfully applied to the determination of heroin and cocaine on illicit drug contaminated banknotes without any damage of the paper currency. A baseline resolution for heroin and cocaine was achieved within 6 min.

A non-destructive, fast and environmentally friendly procedure has been developed for cocaine determination in euro bank notes. Cocaine was extracted with 15 ml methanol by vortex agitation during 5 min. The extract was evaporated and reconstituted in 0.5 ml methanol. GC-MS-MS analysis was performed using as precursor ion m/z 182.2, with an excitation energy voltage of 1.60 eV, being the product ions measured m/z 150.2 and 82.0. A limit of detection of 0.15 ng per note and a repeatability of 6%, established from the relative standard deviation, of a 1 ng ml(-1) level, were achieved. Recoveries of 101+/-2 and 98+/-3% were obtained for samples spiked with 100 and 10 microg respectively. Results show that all the euro bank notes measured (16 samples) were contaminated with cocaine in the range between 1.25 and 889 microg. Two different contamination levels, high level (150-889 microg) and low one (1.25-77 microg) were found and it could be related with the direct or indirect contact with the drug.

The National Association of Medical Examiners Committee on Cocaine-related Deaths recommends that the following guidelines be applied in the process of documenting, interpreting, and certifying potential cocaine-related fatalities. The committee cautions that the investigation of any drug-related death requires a complete investigation of the circumstances of death, the death scene, and past medical history. It is also necessary to have the results of the forensic toxicological analysis and those of a complete forensic autopsy examination prior to formulating an opinion as to the cause and manner of death. Cocaine should be considered the underlying cause of the death when 1 or more of the following is true: (1). the circumstances surrounding the death can be associated with an acute cocaine exposure and there are no supervening causes of death; (2). the immediate cause of death is directly due to a readily identifiable mechanism or disease such as a gunshot wound or a stroke, yet the acute use of cocaine was the direct underlying cause of the trauma or the disease process; and (3). chronic cocaine use leads to a disease that results in an ultimately fatal pathologic process leading to organ injury and death. The committee further cautions that reported drug levels may not directly relate to the toxic or lethal effects of the drug upon the patient. These guidelines are intended for use by practicing medical examiners and physicians who certify drug deaths, as well as providing education tools for students.

Bundles of paper, similar to sterling banknotes, were counted in banks in England and Wales. Subsequent analysis showed that the counting process, both by machine and by hand, transferred nanogram amounts of cocaine to the paper. Crystalline material, similar to cocaine hydrochloride, could be observed on the surface of the paper following counting. The geographical distribution of contamination broadly followed Government statistics for cocaine usage within the UK. Diacetylmorphine, Delta(9)-tetrahydrocannabinol (THC) and 3,4-methylenedioxymethylamphetamine (MDMA) were not detected during this study.

Cocaine is one of the most abused illicit drugs, and its abuse damages the central nervous system and can even lead directly to death. Therefore, the development of simple, rapid and highly sensitive detection methods is crucial for the prevention and control of drug abuse, traffic accidents and crime. In this work, an electrochemical aptamer-based (EAB) sensor based on the low-temperature enhancement effect was developed for the direct determination of cocaine in bio-samples. The signal gain of the sensor at 10 °C was greatly improved compared to room temperature, owing to the improved affinity between the aptamer and the target. Additionally, the electroactive area of the gold electrode used to fabricate the EAB sensor was increased 20 times by a simple electrochemical roughening method. The porous electrode possesses more efficient electron transfer and better antifouling properties after roughening. These improvements enabled the sensor to achieve rapid detection of cocaine in complex bio-samples. The low detection limits (LOD) of cocaine in undiluted urine, 50% serum and 50% saliva were 70 nM, 30 nM and 10 nM, respectively, which are below the concentration threshold in drugged driving screening. The aptasensor was simple to construct and reusable, which offers potential for drugged driving screening in the real world., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Sensitive and selective assays are demanded for quantitation of new psychoactive substances such as 4-chloroethcathinone that is a π-conjugated keto compound. Carbon dots (C-dots) prepared from L-arginine through a hydrothermal route have been used for quantitation of 4-chloroethcathinone in aqueous solution and on C-dot-functionalized papers (CDFPs). To prepare CDFPs, chromatography papers, each with a pattern of 8 × 12 circles (wells), are first fabricated through a solid-ink printing method and then the C-dots are coated into the wells. π-Conjugated keto or ester compounds induce photoluminescence quenching of C-dots through an electron transfer process. At pH 7.0, the CDFPs allow screening of abused drugs such as cocaine, heroin and cathinones. Because of poor solubility of heroin and cocaine at pH 11.0, the C-dot probe is selective for cathinones. The C-dots in aqueous solution and CDFPs at pH 11.0 allow quantitation of 4-chloroethcathinone down to 1.73 mM and 0.14 mM, respectively. Our sensing system consisting of a portable UV-lamp, a smartphone and a low-cost CDFP has been used to detect cathinones, cocaine and heroin at pH 7.0, showing its potential for screening of these drugs in crime sites.