Countercurrent chromatography in analytical chemistry (IUPAC technical report)

© 2009 IUPACCountercurrent chromatography (CCC) is a generic term covering all forms of liquid-liquid chromatography that use a support-free liquid stationary phase held in place by a simple centrifugal or complex centrifugal force field. Biphasic liquid systems are used with one liquid phase being the stationary phase and the other being the mobile phase. Although initiated almost 30 years ago, CCC lacked reliable columns. This is changing now, and the newly designed centrifuges appearing on the market make excellent CCC columns. This review focuses on the advantages of a liquid stationary phase and addresses the chromatographic theory of CCC. The main difference with classical liquid chromatography (LC) is the variable volume of the stationary phase. There are mainly two different ways to obtain a liquid stationary phase using centrifugal forces, the hydrostatic way and the hydrodynamic way. These two kinds of CCC columns are described and compared. The reported applications of CCC in analytical chemistry and comparison with other separation and enrichment methods show that the technique can be successfully used in the analysis of plants and other natural products, for the separation of biochemicals and pharmaceuticals, for the separation of alkaloids from medical herbs, in food analysis, etc. On the basis of the studies of the last two decades, recommendations are also given for the application of CCC in trace inorganic analysis and in radioanalytical chemistry

Genome Desertification in Eutherians: Can Gene Deserts Explain the Uneven Distribution of Genes in Placental Mammalian Genomes?

The evolution of genome size as well as structure and organization of genomes belongs among the key questions of genome biology. Here we show, based on a comparative analysis of 30 genomes, that there is generally a tight correlation between the number of genes per chromosome and the length of the respective chromosome in eukaryotic genomes. The surprising exceptions to this pattern are placental mammalian genomes. We identify the number and, more importantly, the uneven distribution of gene deserts among chromosomes, i.e., long (>500 kb) stretches of DNA that do not encode for genes, as the main contributing factor for the observed anomaly of eutherian genomes. Gene-rich placental mammalian chromosomes have smaller proportions of gene deserts and vice versa. We show that the uneven distribution of gene deserts is a derived character state of eutherians. The functional and evolutionary significance of this particular feature of eutherian genomes remains to be explained

Enrichment analysis of Alu elements with different spatial chromatin proximity in the human genome

Transposable elements (TEs) have no longer been totally considered as “junk DNA” for quite a time since the continual discoveries of their multifunctional roles in eukaryote genomes. As one of the most important and abundant TEs that still active in human genome, Alu, a SINE family, has demonstrated its indispensable regulatory functions at sequence level, but its spatial roles are still unclear. Technologies based on 3C(chromosomeconformation capture) have revealed the mysterious three-dimensional structure of chromatin, and make it possible to study the distal chromatin interaction in the genome. To find the role TE playing in distal regulation in human genome, we compiled the new released Hi-C data, TE annotation, histone marker annotations, and the genome-wide methylation data to operate correlation analysis, and found that the density of Alu elements showed a strong positive correlation with the level of chromatin interactions (hESC: r=0.9, P<2.2×1016; IMR90 fibroblasts: r = 0.94, P < 2.2 × 1016) and also have a significant positive correlation withsomeremote functional DNA elements like enhancers and promoters (Enhancer: hESC: r=0.997, P=2.3×10−4; IMR90: r=0.934, P=2×10−2; Promoter: hESC: r = 0.995, P = 3.8 × 10−4; IMR90: r = 0.996, P = 3.2 × 10−4). Further investigation involving GC content and methylation status showed the GC content of Alu covered sequences shared a similar pattern with that of the overall sequence, suggesting that Alu elements also function as the GC nucleotide and CpG site provider. In all, our results suggest that the Alu elements may act as an alternative parameter to evaluate the Hi-C data, which is confirmed by the correlation analysis of Alu elements and histone markers. Moreover, the GC-rich Alu sequence can bring high GC content and methylation flexibility to the regions with more distal chromatin contact, regulating the transcription of tissue-specific genes

Microvessel changes after post-ischemic benign and malignant hyperemia: experimental study in rats

<p>Abstract</p> <p>Background</p> <p>The present investigation was designed to elucidate the use of dynamic contrast enhanced perfusion MR imaging (DCE pMRI) in characterizing hyperemia, including microvessel changes, and to examine whether DCE pMRI can predict benign or malignant hyperemia.</p> <p>Methods</p> <p>Sprague-Dawley rats underwent middle cerebral artery occlusion (MCAO) by intraluminal suture placement. All rats were randomized to 4 groups: MCAO for 0.5 hours followed by saline treatment (10 ml/kg; group 1); MCAO for 3 hours followed by treatment with saline (group 2) or urokinase (25000 IU/kg; group 3); and MCAO for 6 hours followed by urokinase treatment (group 4). Relative cerebral blood volume (rCBV) and relative maximum slope of increase of the signal intensity time curve (rMSI) were quantitatively analyzed from MRI. Microvessel diameter and blood-brain barrier disruption obtained by laser scanning confocal microscopy (LSCM) as well as transmission electron microscopy (TEM) were obtained for correlative study.</p> <p>Results</p> <p>Benign hyperemia was noticed only in group 1; malignant hyperemia was seen in group 3. Although the rCBV of malignant hyperemia was slightly higher than in benign hyperemia (<it>P </it>> 0.05), the rMSI, on the other hand, was significantly lower (<it>P </it>< 0.05). Fluoro-isothiocyanate dextran (FITC-dextran) extravasations, marked glial end-foot process swelling, and significant vasodilatation were seen in malignant hyperemia, while no or mild leakage of FITC-dextran and slight glial end-foot process swelling occurred in benign hyperemia.</p> <p>Conclusion</p> <p>Our findings indicate that DCE pMRI can characterize post-ischemic hyperemia and correlates well with microvascular damage.</p

Proliferation of Ty3/gypsy-like retrotransposons in hybrid sunflower taxa inferred from phylogenetic data

<p>Abstract</p> <p>Background</p> <p>Long terminal repeat (LTR) retrotransposons are a class of mobile genetic element capable of autonomous transposition via an RNA intermediate. Their large size and proliferative ability make them important contributors to genome size evolution, especially in plants, where they can reach exceptionally high copy numbers and contribute substantially to variation in genome size even among closely related taxa. Using a phylogenetic approach, we characterize dynamics of proliferation events of <it>Ty3/gypsy</it>-like LTR retrotransposons that led to massive genomic expansion in three <it>Helianthus </it>(sunflower) species of ancient hybrid origin. The three hybrid species are independently derived from the same two parental species, offering a unique opportunity to explore patterns of retrotransposon proliferation in light of reticulate evolutionary events in this species group.</p> <p>Results</p> <p>We demonstrate that <it>Ty3/gypsy</it>-like retrotransposons exist as multiple well supported sublineages in both the parental and hybrid derivative species and that the same element sublineage served as the source lineage of proliferation in each hybrid species' genome. This inference is based on patterns of species-specific element numerical abundance within different phylogenetic sublineages as well as through signals of proliferation events present in the distributions of element divergence values. Employing methods to date paralogous sequences within a genome, proliferation events in the hybrid species' genomes are estimated to have occurred approximately 0.5 to 1 million years ago.</p> <p>Conclusion</p> <p>Proliferation of the same retrotransposon major sublineage in each hybrid species indicates that similar dynamics of element derepression and amplification likely occurred in each hybrid taxon during their formation. Temporal estimates of these proliferation events suggest an earlier origin for these hybrid species than previously supposed.</p

Farmer attitudes and livestock disease: exploring citizenship behaviour and peer monitoring across two BVD control schemes in the UK

The eradication of BVD in the UK is technically possible but appears to be socially untenable. The following study explored farmer attitudes to BVD control schemes in relation to advice networks and information sharing, shared aims and goals, motivation and benefits of membership, notions of BVD as a priority disease and attitudes toward regulation. Two concepts from the organisational management literature framed the study: citizenship behaviour where actions of individuals support the collective good (but are not explicitly recognised as such) and peer to peer monitoring (where individuals evaluate other’s behaviour). Farmers from two BVD control schemes in the UK participated in the study: Orkney Livestock Association BVD Eradication Scheme and Norfolk and Suffolk Cattle Breeders Association BVD Eradication Scheme. In total 162 farmers participated in the research (109 in-scheme and 53 out of scheme). The findings revealed that group helping and information sharing among scheme members was low with a positive BVD status subject to social censure. Peer monitoring in the form of gossip with regard to the animal health status of other farms was high. Interestingly, farmers across both schemes supported greater regulation with regard to animal health, largely due to the mistrust of fellow farmers following voluntary disease control measures. While group cohesiveness varied across the two schemes, without continued financial inducements, longer-term sustainability is questionabl

Structural characterization of helitrons and their stepwise capturing of gene fragments in the maize genome

<p>Abstract</p> <p>Background</p> <p>As a newly identified category of DNA transposon, <it>helitrons </it>have been found in a large number of eukaryotes genomes. <it>Helitrons </it>have contributed significantly to the intra-specific genome diversity in maize. Although many characteristics of <it>helitrons </it>in the maize genome have been well documented, the sequence of an intact autonomous <it>helitrons </it>has not been identified in maize. In addition, the process of gene fragment capturing during the transposition of <it>helitrons </it>has not been characterized.</p> <p>Results</p> <p>The whole genome sequences of maize inbred line B73 were analyzed, 1,649 <it>helitron</it>-like transposons including 1,515 helAs and 134 helBs were identified. <it>ZmhelA1</it>, <it>ZmhelB1 </it>and <it>ZmhelB2 </it>all encode an open reading frame (ORF) with intact replication initiator (Rep) motif and a DNA helicase (Hel) domain, which are similar to previously reported autonomous <it>helitrons </it>in other organisms. The putative autonomous <it>ZmhelB1 </it>and <it>ZmhelB2 </it>contain an extra replication factor-a protein1 (RPA1) transposase (RPA-TPase) including three single strand DNA-binding domains (DBD)-A/-B/-C in the ORF. Over ninety percent of maize <it>helitrons </it>identified have captured gene fragments. HelAs and helBs carry 4,645 and 249 gene fragments, which yield 2,507 and 187 different genes respectively. Many <it>helitrons </it>contain mutilple terminal sequences, but only one 3'-terminal sequence had an intact "CTAG" motif. There were no significant differences in the 5'-termini sequence between the veritas terminal sequence and the pseudo sequence. <it>Helitrons </it>not only can capture fragments, but were also shown to lose internal sequences during the course of transposing.</p> <p>Conclusions</p> <p>Three putative autonomous elements were identified, which encoded an intact Rep motif and a DNA helicase domain, suggesting that autonomous <it>helitrons </it>may exist in modern maize. The results indicate that gene fragments captured during the transposition of many <it>helitrons </it>happen in a stepwise way, with multiple gene fragments within one <it>helitron </it>resulting from several sequential transpositions. In addition, we have proposed a potential mechanism regarding how <it>helitrons </it>with multiple termini are generated.</p

Tm1: A Mutator/Foldback Transposable Element Family in Root-Knot Nematodes

Three closely related parthenogenetic species of root-knot nematodes, collectively termed the Meloidogyne incognita-group, are economically significant pathogens of diverse crop species. Remarkably, these asexual root-knot nematodes are capable of acquiring heritable changes in virulence even though they lack sexual reproduction and meiotic recombination. Characterization of a near isogenic pair of M. javanica strains differing in response to tomato with the nematode resistance gene Mi-1 showed that the virulent strain carried a deletion spanning a gene called Cg-1. Herein, we present evidence that the Cg-1 gene lies within a member of a novel transposable element family (Tm1; Transposon in Meloidogyne-1). This element family is defined by composite terminal inverted repeats of variable lengths similar to those of Foldback (FB) transposable elements and by 9 bp target site duplications. In M. incognita, Tm1 elements can be classified into three general groups: 1) histone-hairpin motif elements; 2) MITE-like elements; 3) elements encoding a putative transposase. The predicted transposase shows highest similarity to gene products encoded by aphids and mosquitoes and resembles those of the Phantom subclass of the Mutator transposon superfamily. Interestingly, the meiotic, sexually-reproducing root-knot nematode species M. hapla has Tm1 elements with similar inverted repeat termini, but lacks elements with histone hairpin motifs and contains no elements encoding an intact transposase. These Tm1 elements may have impacts on root-knot nematode genomes and contribute to genetic diversity of the asexual species

The Random Nature of Genome Architecture: Predicting Open Reading Frame Distributions

Background: A better understanding of the size and abundance of open reading frames (ORFS) in whole genomes may shed light on the factors that control genome complexity. Here we examine the statistical distributions of open reading frames (i.e. distribution of start and stop codons) in the fully sequenced genomes of 297 prokaryotes, and 14 eukaryotes. Methodology/Principal Findings: By fitting mixture models to data from whole genome sequences we show that the size-frequency distributions for ORFS are strikingly similar across prokaryotic and eukaryotic genomes. Moreover, we show that i) a large fraction (60–80%) of ORF size-frequency distributions can be predicted a priori with a stochastic assembly model based on GC content, and that (ii) size-frequency distributions of the remaining “non-random” ORFs are well-fitted by log-normal or gamma distributions, and similar to the size distributions of annotated proteins. Conclusions/Significance: Our findings suggest stochastic processes have played a primary role in the evolution of genome complexity, and that common processes govern the conservation and loss of functional genomics units in both prokaryotes and eukaryotes.8 page(s

Chromogenic and Fluorogenic Probes for the Detection of Illicit Drugs

[EN] The consumption of illicit drugs has increased exponentially in recent years and has become a problem that worries both governments and international institutions. The rapid emergence of new compounds, their easy access, the low levels at which these substances are able to produce an effect, and their short time of permanence in the organism make it necessary to develop highly rapid, easy, sensitive, and selective methods for their detection. Currently, the most widely used methods for drug detection are based on techniques that require large measurement times, the use of sophisticated equipment, and qualified personnel. Chromo- and fluorogenic methods are an alternative to those classical procedures.We thank the Spanish Government [projects MAT2015-64139-C4-1-R and AGL2015-70235-C2-2-R (MINECO/FEDER)] and the Generalitat Valenciana (project PROMETEOII/2014/047) for support. S.E.S thanks the Ministerio de Economia y Competitividad for his Juan de la Cierva contract. B.L.T and E.G. thank the Spanish Government for their predoctoral grants. L.P. also thanks the Universitat Politecnica de Valencia for his predoctoral grant.Garrido-García, EM.; Pla, L.; Lozano-Torres, B.; El Sayed Shehata Nasr, S.; Martínez-Máñez, R.; Sancenón Galarza, F. (2018). Chromogenic and Fluorogenic Probes for the Detection of Illicit Drugs. ChemistryOpen. 7(5):401-428. https://doi.org/10.1002/open.201800034S40142875Komoroski, E. M., Komoroski, R. A., Valentine, J. L., Pearce, J. M., & Kearns, G. L. (2000). The Use of Nuclear Magnetic Resonance Spectroscopy in the Detection of Drug Intoxication. Journal of Analytical Toxicology, 24(3), 180-187. doi:10.1093/jat/24.3.180Drugs of Abuse: A DEA Resource Guide 2017World Drug Report 2017European Drug Report: Trends and Developments 2017Namera, A., Nakamoto, A., Saito, T., & Nagao, M. (2011). Colorimetric detection and chromatographic analyses of designer drugs in biological materials: a comprehensive review. Forensic Toxicology, 29(1), 1-24. doi:10.1007/s11419-010-0107-9Namera, A., Kawamura, M., Nakamoto, A., Saito, T., & Nagao, M. (2015). Comprehensive review of the detection methods for synthetic cannabinoids and cathinones. Forensic Toxicology, 33(2), 175-194. doi:10.1007/s11419-015-0270-0Kidwell, D. A., Holland, J. C., & Athanaselis, S. (1998). Testing for drugs of abuse in saliva and sweat. Journal of Chromatography B: Biomedical Sciences and Applications, 713(1), 111-135. doi:10.1016/s0378-4347(97)00572-0Cappelle, D., De Doncker, M., Gys, C., Krysiak, K., De Keukeleire, S., Maho, W., … Neels, H. (2017). A straightforward, validated liquid chromatography coupled to tandem mass spectrometry method for the simultaneous detection of nine drugs of abuse and their metabolites in hair and nails. Analytica Chimica Acta, 960, 101-109. doi:10.1016/j.aca.2017.01.022Koster, R. A., Alffenaar, J.-W. C., Greijdanus, B., VanDerNagel, J. E. L., & Uges, D. R. A. (2014). Fast and Highly Selective LC-MS/MS Screening for THC and 16 Other Abused Drugs and Metabolites in Human Hair to Monitor Patients for Drug Abuse. Therapeutic Drug Monitoring, 36(2), 234-243. doi:10.1097/ftd.0b013e3182a377e8Li, Y., Uddayasankar, U., He, B., Wang, P., & Qin, L. (2017). Fast, Sensitive, and Quantitative Point-of-Care Platform for the Assessment of Drugs of Abuse in Urine, Serum, and Whole Blood. Analytical Chemistry, 89(16), 8273-8281. doi:10.1021/acs.analchem.7b01288De la Asunción-Nadal, V., Armenta, S., Garrigues, S., & de la Guardia, M. (2017). Identification and determination of synthetic cannabinoids in herbal products by dry film attenuated total reflectance-infrared spectroscopy. Talanta, 167, 344-351. doi:10.1016/j.talanta.2017.02.026Risoluti, R., Materazzi, S., Gregori, A., & Ripani, L. (2016). Early detection of emerging street drugs by near infrared spectroscopy and chemometrics. Talanta, 153, 407-413. doi:10.1016/j.talanta.2016.02.044Andreou, C., Hoonejani, M. R., Barmi, M. R., Moskovits, M., & Meinhart, C. D. (2013). Rapid Detection of Drugs of Abuse in Saliva Using Surface Enhanced Raman Spectroscopy and Microfluidics. ACS Nano, 7(8), 7157-7164. doi:10.1021/nn402563fHe, S., Liu, D., Wang, Z., Cai, K., & Jiang, X. (2011). Utilization of unmodified gold nanoparticles in colorimetric detection. Science China Physics, Mechanics and Astronomy, 54(10), 1757-1765. doi:10.1007/s11433-011-4486-7Substance Abuse (Depressants or Sedative-Hypnotic Drugs) 2014Zhai, D., Agrawalla, B. K., Eng, P. S. F., Lee, S.-C., Xu, W., & Chang, Y.-T. (2013). Development of a fluorescent sensor for an illicit date rape drug – GBL. Chemical Communications, 49(55), 6170. doi:10.1039/c3cc43153cZhai, D., Tan, Y. Q. E., Xu, W., & Chang, Y.-T. (2014). Development of a fluorescent sensor for illicit date rape drug GHB. Chemical Communications, 50(22), 2904. doi:10.1039/c3cc49603aBaumes, L. A., Buaki Sogo, M., Montes-Navajas, P., Corma, A., & Garcia, H. (2010). A Colorimetric Sensor Array for the Detection of the Date-Rape Drug γ-Hydroxybutyric Acid (GHB): A Supramolecular Approach. Chemistry - A European Journal, 16(15), 4489-4495. doi:10.1002/chem.200903127Wang, W., Dong, Z.-Z., Yang, G., Leung, C.-H., Lin, S., & Ma, D.-L. (2017). A long-lived iridium(iii) chemosensor for the real-time detection of GHB. Journal of Materials Chemistry B, 5(15), 2739-2742. doi:10.1039/c6tb03396bMorris, J. A. (2007). Modified Cobalt Thiocyanate Presumptive Color Test for Ketamine Hydrochloride. Journal of Forensic Sciences, 52(1), 84-87. doi:10.1111/j.1556-4029.2006.00331.xMerck Manual Drug Information 2014Argente-García, A., Jornet-Martínez, N., Herráez-Hernández, R., & Campíns-Falcó, P. (2017). A passive solid sensor for in-situ colorimetric estimation of the presence of ketamine in illicit drug samples. Sensors and Actuators B: Chemical, 253, 1137-1144. doi:10.1016/j.snb.2017.07.183ELMOSALLAMY, M. A. F., & AMIN, A. S. (2014). New Potentiometric and Spectrophotometric Methods for the Determination of Dextromethorphan in Pharmaceutical Preparations. Analytical Sciences, 30(3), 419-425. doi:10.2116/analsci.30.419Mohseni, N., & Bahram, M. (2016). Mean centering of ratio spectra for colorimetric determination of morphine and codeine in pharmaceuticals and biological samples using melamine modified gold nanoparticles. Anal. Methods, 8(37), 6739-6747. doi:10.1039/c6ay02091gSAKAI, T., & OHNO, N. (1986). Spectrophotometric determination of stimulant drugs in urine by color reaction with tetrabromophenolphthalein ethyl ester. Analytical Sciences, 2(3), 275-279. doi:10.2116/analsci.2.275Sakai, T., & Ohno, N. (1987). Improved determination of methamphetamine, ephedrine and methylephedrine in urine by extraction-thermospectrometry. The Analyst, 112(2), 149. doi:10.1039/an9871200149Argente-García, A., Jornet-Martínez, N., Herráez-Hernández, R., & Campíns-Falcó, P. (2016). A solid colorimetric sensor for the analysis of amphetamine-like street samples. Analytica Chimica Acta, 943, 123-130. doi:10.1016/j.aca.2016.09.020Guler, E., Yilmaz Sengel, T., Gumus, Z. P., Arslan, M., Coskunol, H., Timur, S., & Yagci, Y. (2017). Mobile Phone Sensing of Cocaine in a Lateral Flow Assay Combined with a Biomimetic Material. Analytical Chemistry, 89(18), 9629-9632. doi:10.1021/acs.analchem.7b03017Choodum, A., Parabun, K., Klawach, N., Daeid, N. N., Kanatharana, P., & Wongniramaikul, W. (2014). Real time quantitative colourimetric test for methamphetamine detection using digital and mobile phone technology. Forensic Science International, 235, 8-13. doi:10.1016/j.forsciint.2013.11.018Choodum, A., Kanatharana, P., Wongniramaikul, W., & NicDaeid, N. (2015). A sol–gel colorimetric sensor for methamphetamine detection. Sensors and Actuators B: Chemical, 215, 553-560. doi:10.1016/j.snb.2015.03.089Moreno, D., Greñu, B. D. de, García, B., Ibeas, S., & Torroba, T. (2012). A turn-on fluorogenic probe for detection of MDMA from ecstasy tablets. Chemical Communications, 48(24), 2994. doi:10.1039/c2cc17823kFu, Y., Shi, L., Zhu, D., He, C., Wen, D., He, Q., … Cheng, J. (2013). Fluorene–thiophene-based thin-film fluorescent chemosensor for methamphetamine vapor by thiophene–amine interaction. Sensors and Actuators B: Chemical, 180, 2-7. doi:10.1016/j.snb.2011.10.031He, M., Peng, H., Wang, G., Chang, X., Miao, R., Wang, W., & Fang, Y. (2016). Fabrication of a new fluorescent film and its superior sensing performance to N-methamphetamine in vapor phase. Sensors and Actuators B: Chemical, 227, 255-262. doi:10.1016/j.snb.2015.12.048Lozano-Torres, B., Pascual, L., Bernardos, A., Marcos, M. D., Jeppesen, J. O., Salinas, Y., … Sancenón, F. (2017). Pseudorotaxane capped mesoporous silica nanoparticles for 3,4-methylenedioxymethamphetamine (MDMA) detection in water. Chemical Communications, 53(25), 3559-3562. doi:10.1039/c7cc00186jHe, C., He, Q., Deng, C., Shi, L., Fu, Y., Cao, H., & Cheng, J. (2011). Determination of Methamphetamine Hydrochloride by highly fluorescent polyfluorene with NH2-terminated side chains. Synthetic Metals, 161(3-4), 293-297. doi:10.1016/j.synthmet.2010.11.038Masseroni, D., Biavardi, E., Genovese, D., Rampazzo, E., Prodi, L., & Dalcanale, E. (2015). A fluorescent probe for ecstasy. Chemical Communications, 51(64), 12799-12802. doi:10.1039/c5cc04760aReviriego, F., Navarro, P., García-España, E., Albelda, M. T., Frías, J. C., Domènech, A., … Ortí, E. (2008). Diazatetraester 1H-Pyrazole Crowns as Fluorescent Chemosensors for AMPH, METH, MDMA (Ecstasy), and Dopamine. Organic Letters, 10(22), 5099-5102. doi:10.1021/ol801732tYamada, H., Ikeda-Wada, S., & Oguri, K. (1999). Highly Specific and Convenient Color Reaction for Methylenedioxymethamphetamine and Related Drugs Using Chromotropic Acid. Application as a Drug Screening Test. JOURNAL OF HEALTH SCIENCE, 45(6), 303-308. doi:10.1248/jhs.45.303Matsuda, K., Fukuzawa, T., Ishii, Y., & Yamada, H. (2007). Color reaction of 3,4-methylenedioxyamphetamines with chromotropic acid: its improvement and application to the screening of seized tablets. Forensic Toxicology, 25(1), 37-40. doi:10.1007/s11419-007-0022-xRouhani, S., & Haghgoo, S. (2015). A novel fluorescence nanosensor based on 1,8-naphthalimide-thiophene doped silica nanoparticles, and its application to the determination of methamphetamine. Sensors and Actuators B: Chemical, 209, 957-965. doi:10.1016/j.snb.2014.12.035Maue, M., & Schrader, T. (2005). A Color Sensor for Catecholamines. Angewandte Chemie International Edition, 44(15), 2265-2270. doi:10.1002/anie.200462702Maue, M., & Schrader, T. (2005). A Color Sensor for Catecholamines. Angewandte Chemie, 117(15), 2305-2310. doi:10.1002/ange.200462702Mosnaim, A. D., & Inwang, E. E. (1973). A spectrophotometric method for the quantification of 2-phenylethylamine in biological specimens. Analytical Biochemistry, 54(2), 561-577. doi:10.1016/0003-2697(73)90388-6Wang, D., Liu, T.-J., Zhang, W.-C., Zhang, W.-C., Slaven IV, W. T., & Li, C.-J. (1998). Enantiomeric discrimination of chiral amines with new fluorescent chemosensors. Chemical Communications, (16), 1747-1748. doi:10.1039/a802855iEl-Didamony, A. M., & Gouda, A. A. (2010). A novel spectrofluorimetric method for the assay of pseudoephedrine hydrochloride in pharmaceutical formulations via derivatization with 4-chloro-7-nitrobenzofurazan. Luminescence, 26(6), 510-517. doi:10.1002/bio.1261Mazina, J., Aleksejev, V., Ivkina, T., Kaljurand, M., & Poryvkina, L. (2012). Qualitative detection of illegal drugs (cocaine, heroin and MDMA) in seized street samples based on SFS data and ANN: validation of method. Journal of Chemometrics, 26(8-9), 442-455. doi:10.1002/cem.2462Sefah, K., Shangguan, D., Xiong, X., O’Donoghue, M. B., & Tan, W. (2010). Development of DNA aptamers using Cell-SELEX. Nature Protocols, 5(6), 1169-1185. doi:10.1038/nprot.2010.66Shi, Q., Shi, Y., Pan, Y., Yue, Z., Zhang, H., & Yi, C. (2014). Colorimetric and bare eye determination of urinary methylamphetamine based on the use of aptamers and the salt-induced aggregation of unmodified gold nanoparticles. Microchimica Acta, 182(3-4), 505-511. doi:10.1007/s00604-014-1349-8Mao, K., Yang, Z., Du, P., Xu, Z., Wang, Z., & Li, X. (2016). G-quadruplex–hemin DNAzyme molecular beacon probe for the detection of methamphetamine. RSC Advances, 6(67), 62754-62759. doi:10.1039/c6ra04912eShlyahovsky, B., Li, D., Weizmann, Y., Nowarski, R., Kotler, M., & Willner, I. (2007). Spotlighting of Cocaine by an Autonomous Aptamer-Based Machine. Journal of the American Chemical Society, 129(13), 3814-3815. doi:10.1021/ja069291nWang, F., Freage, L., Orbach, R., & Willner, I. (2013). Autonomous Replication of Nucleic Acids by Polymerization/Nicking Enzyme/DNAzyme Cascades for the Amplified Detection of DNA and the Aptamer–Cocaine Complex. Analytical Chemistry, 85(17), 8196-8203. doi:10.1021/ac4013094Wang, J., Song, J., Wang, X., Wu, S., Zhao, Y., Luo, P., & Meng, C. (2016). An ATMND/SGI based label-free and fluorescence ratiometric aptasensor for rapid and highly sensitive detection of cocaine in biofluids. Talanta, 161, 437-442. doi:10.1016/j.talanta.2016.08.039Huang, J., Chen, Y., Yang, L., Zhu, Z., Zhu, G., Yang, X., … Tan, W. (2011). Amplified detection of cocaine based on strand-displacement polymerization and fluorescence resonance energy transfer. Biosensors and Bioelectronics, 28(1), 450-453. doi:10.1016/j.bios.2011.05.038Zhang, C., & Johnson, L. W. (2009). Single Quantum-Dot-Based Aptameric Nanosensor for Cocaine. Analytical Chemistry, 81(8), 3051-3055. doi:10.1021/ac802737bEmrani, A. S., Danesh, N. M., Ramezani, M., Taghdisi, S. M., & Abnous, K. (2016). A novel fluorescent aptasensor based on hairpin structure of complementary strand of aptamer and nanoparticles as a signal amplification approach for ultrasensitive detection of cocaine. Biosensors and Bioelectronics, 79, 288-293. doi:10.1016/j.bios.2015.12.025Roncancio, D., Yu, H., Xu, X., Wu, S., Liu, R., Debord, J., … Xiao, Y. (2014). A Label-Free Aptamer-Fluorophore Assembly for Rapid and Specific Detection of Cocaine in Biofluids. Analytical Chemistry, 86(22), 11100-11106. doi:10.1021/ac503360nGuler, E., Bozokalfa, G., Demir, B., Gumus, Z. P., Guler, B., Aldemir, E., … Coskunol, H. (2016). An aptamer folding-based sensory platform decorated with nanoparticles for simple cocaine testing. Drug Testing and Analysis, 9(4), 578-587. doi:10.1002/dta.1992Ribes, À., Xifré -Pérez, E., Aznar, E., Sancenón, F., Pardo, T., Marsal, L. F., & Martínez-Máñez, R. (2016). Molecular gated nanoporous anodic alumina for the detection of cocaine. Scientific Reports, 6(1). doi:10.1038/srep38649Marsal, L. F., Vojkuvka, L., Formentin, P., Pallarés, J., & Ferré-Borrull, J. (2009). Fabrication and optical characterization of nanoporous alumina films annealed at different temperatures. Optical Materials, 31(6), 860-864. doi:10.1016/j.optmat.2008.09.008Oroval, M., Coronado-Puchau, M., Langer, J., Sanz-Ortiz, M. N., Ribes, Á., Aznar, E., … Martínez-Máñez, R. (2016). Surface Enhanced Raman Scattering and Gated Materials for Sensing Applications: The Ultrasensitive Detection ofMycoplasmaand Cocaine. Chemistry - A European Journal, 22(38), 13488-13495. doi:10.1002/chem.201602457Stojanovic, M. N., de Prada, P., & Landry, D. W. (2000). Fluorescent Sensors Based on Aptamer Self-Assembly. Journal of the American Chemical Society, 122(46), 11547-11548. doi:10.1021/ja0022223Stojanovic, M. N., de Prada, P., & Landry, D. W. (2001). Aptamer-Based Folding Fluorescent Sensor for Cocaine. Journal of the American Chemical Society, 123(21), 4928-4931. doi:10.1021/ja0038171Stojanovic, M. N., & Landry, D. W. (2002). Aptamer-Based Colorimetric Probe for Cocaine. Journal of the American Chemical Society, 124(33), 9678-9679. doi:10.1021/ja0259483Liu, Y., & Zhao, Q. (2017). Direct fluorescence anisotropy assay for cocaine using tetramethylrhodamine-labeled aptamer. Analytical and Bioanalytical Chemistry, 409(16), 3993-4000. doi:10.1007/s00216-017-0349-zZhou, Z., Du, Y., & Dong, S. (2011). Double-Strand DNA-Templated Formation of Copper Nanoparticles as Fluorescent Probe for Label-Free Aptamer Sensor. Analytical Chemistry, 83(13), 5122-5127. doi:10.1021/ac200120gShi, Y., Dai, H., Sun, Y., Hu, J., Ni, P., & Li, Z. (2013). Fluorescent sensing of cocaine based on a structure switching aptamer, gold nanoparticles and graphene oxide. The Analyst, 138(23), 7152. doi:10.1039/c3an00897eZhang, Y., Sun, Z., Tang, L., Zhang, H., & Zhang, G.-J. (2016). Aptamer based fluorescent cocaine assay based on the use of graphene oxide and exonuclease III-assisted signal amplification. Microchimica Acta, 183(10), 2791-2797. doi:10.1007/s00604-016-1923-3Zhang, J., Wang, L., Pan, D., Song, S., Boey, F. Y. C., Zhang, H., & Fan, C. (2008). Visual Cocaine Detection with Gold Nanoparticles and Rationally Engineered Aptamer Structures. Small, 4(8), 1196-1200. doi:10.1002/smll.200800057Li, Y., Ji, X., & Liu, B. (2011). Chemiluminescence aptasensor for cocaine based on double-functionalized gold nanoprobes and functionalized magnetic microbeads. Analytical and Bioanalytical Chemistry, 401(1), 213-219. doi:10.1007/s00216-011-5064-6Zou, R., Lou, X., Ou, H., Zhang, Y., Wang, W., Yuan, M., … Liu, Y. (2012). Highly specific triple-fragment aptamer for optical detection of cocaine. RSC Advances, 2(11), 4636. doi:10.1039/c2ra20307cZhang, S., Wang, L., Liu, M., Qiu, Y., Wang, M., Liu, X., … Yu, R. (2016). A novel, label-free fluorescent aptasensor for cocaine detection based on a G-quadruplex and ruthenium polypyridyl complex molecular light switch. Analytical Methods, 8(18), 3740-3746. doi:10.1039/c6ay00231eTang, Y., Long, F., Gu, C., Wang, C., Han, S., & He, M. (2016). Reusable split-aptamer-based biosensor for rapid detection of cocaine in serum by using an all-fiber evanescent wave optical biosensing platform. Analytica Chimica Acta, 933, 182-188. doi:10.1016/j.aca.2016.05.021Wang, L., Musile, G., & McCord, B. R. (2017). An aptamer-based paper microfluidic device for the colorimetric determination of cocaine. ELECTROPHORESIS, 39(3), 470-475. doi:10.1002/elps.201700254Liu, J., & Lu, Y. (2006). Fast Colorimetric Sensing of Adenosine and Cocaine Based on a General Sensor Design Involving Aptamers and Nanoparticles. Angewandte Chemie International Edition, 45(1), 90-94. doi:10.1002/anie.200502589Liu, J., & Lu, Y. (2006). Fast Colorimetric Sensing of Adenosine and Cocaine Based on a General Sensor Design Involving Aptamers and Nanoparticles. Angewandte Chemie, 118(1), 96-100. doi:10.1002/ange.200502589He, M., Li, Z., Ge, Y., & Liu, Z. (2016). Portable Upconversion Nanoparticles-Based Paper Device for Field Testing of Drug Abuse. Analytical Chemistry, 88(3), 1530-1534. doi:10.1021/acs.analchem.5b04863Qiu, L., Zhou, H., Zhu, W., Qiu, L., Jiang, J., Shen, G., & Yu, R. (2013). A novel label-free fluorescence aptamer-based sensor method for cocaine detection based on isothermal circular strand-displacement amplification and graphene oxide absorption. New Journal of Chemistry, 37(12), 3998. doi:10.1039/c3nj00594aArslan, M., Yilmaz Sengel, T., Guler, E., Gumus, Z. P., Aldemir, E., Akbulut, H., … Yagci, Y. (2017). Double fluorescence assay via a β-cyclodextrin containing conjugated polymer as a biomimetic material for cocaine sensing. Polymer Chemistry, 8(21), 3333-3340. doi:10.1039/c7py00420fMao, K., Yang, Z., Li, J., Zhou, X., Li, X., & Hu, J. (2017). A novel colorimetric biosensor based on non-aggregated Au@Ag core–shell nanoparticles for methamphetamine and cocaine detection. Talanta, 175, 338-346. doi:10.1016/j.talanta.2017.07.011Ma, D.-L., Wang, M., He, B., Yang, C., Wang, W., & Leung, C.-H. (2015). A Luminescent Cocaine Detection Platform Using a Split G-Quadruplex-Selective Iridium(III) Complex and a Three-Way DNA Junction Architecture. ACS Applied Materials & Interfaces, 7(34), 19060-19067. doi:10.1021/acsami.5b05861Du, Y., Li, B., Guo, S., Zhou, Z., Zhou, M., Wang, E., & Dong, S. (2011). G-Quadruplex-based DNAzyme for colorimetric detection ofcocaine: Using magnetic nanoparticles as the separation and amplification element. The Analyst, 136(3), 493-497. doi:10.1039/c0an00557fZhang, K., Wang, K., Zhu, X., Zhang, J., Xu, L., Huang, B., & Xie, M. (2014). Label-free and ultrasensitive fluorescence detection of cocaine based on a strategy that utilizes DNA-templated silver nanoclusters and the nicking endonuclease-assisted signal amplification method. Chem. Commun., 50(2), 180-182. doi:10.1039/c3cc47418fZhou, J., Ellis, A. V., Kobus, H., & Voelcker, N. H. (2012). Aptamer sensor for cocaine using minor groove binder based energy transfer. Analytica Chimica Acta, 719, 76-81. doi:10.1016/j.aca.2012.01.011Drug Facts 2016Baudot, P., & Andre, J.-C. (1983). A Low-Cost Differential Fluorimeter for the Detection and Determination of LSD in Illicit Preparations. Journal of Analytical Toxicology, 7(2), 69-71. doi:10.1093/jat/7.2.69Mohseni, N., Bahram, M., & Baheri, T. (2017). Chemical nose for discrimination of opioids based on unmodified gold nanoparticles. Sensors and Actuators B: Chemical, 250, 509-517. doi:10.1016/j.snb.2017.04.145Shcherbakova, E. G., Zhang, B., Gozem, S., Minami, T., Zavalij, P. Y., Pushina, M., … Anzenbacher, P. (2017). Supramolecular Sensors for Opiates and Their Metabolites. Journal of the American Chemical Society, 139(42), 14954-14960. doi:10.1021/jacs.7b0637