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Zn.sup.2+ and Cu.sup.2+ related to transition metal ions present in foods play essential roles in the health of human and animal metabolism. However, the excess of these ions contaminates foods and causes many kinds of diseases. In recent years, designing chemosensors for detection of the two targets has been widespread but is still a great challenge for practical application. In this study, by reducing expenses, simplifying analytical procedures, and enabling multifunctions, a functional chemosensor was proposed by using tetraphenylethylene derivative (H.sub.4tcbpe) which could selectively and sensitively response to Zn.sup.2+ and Cu.sup.2+. H.sub.4tcbpe can be used to detect Zn.sup.2+ with fluorescence enhancement based on aggregation induced emission effect, while fluorescence of H.sub.4tcbpe can be quenched by Cu.sup.2+ due to the disassembly of H.sub.4tcbpe aggregates in a solvent/nonsolvent binary mixture of EtOH and H.sub.2O. Fluorophotometry, UV-Vis, and SEM were used to characterize behavior of the fluorescence sensor. In this work, the detection in liquid solutions was conducted, and a fluorescent test pen for the assay of Zn.sup.2+ and Cu.sup.2+ on a piece of filter paper was fabricated. The proposed fluorescent test pen contained H.sub.4tcbpe as a 'fluorescent probe ink' and made it possible to write words on the area of a filter paper spiked with solutions with different concentrations of Zn.sup.2+ and Cu.sup.2+. The detection limits for Zn.sup.2+ and Cu.sup.2+ are 43 nM and 0.5 [mu]M, respectively. This fluorescent sensor was applied to sense ions in black fungus samples. The proposed sensor could successfully detect Zn.sup.2+ and Cu.sup.2+, and the results were in agreement with the data from inductively coupled plasma mass spectrometry, which indicated the reliability of the proposed sensor for applications in the real samples., Author(s): Xiujuan Qiao [sup.1] [sup.2] , Gengjia Chen [sup.1] , Tianli Yue [sup.1] , Qinglin Sheng [sup.1] Author Affiliations: (1) grid.412262.1, 0000 0004 1761 5538, College of Food Science and [...]

A novel, simple, and low-cost spray painting technique has been developed for the fabrication of microfluidic paper-based devices. The devices that we developed utilize aerosol spray paint to build hydrophobic barriers and employ a hole puncher to obtain paper-based patterned layers and paper dots without using any specialized instruments (e.g., without a laser cutter). The entire manufacturing process is extremely simple, inexpensive, and rapid, which means that it can be applied broadly. Furthermore, the application of the device to iron detection was demonstrated. A linear relationship between the colour value and the iron concentration was observed from 0 to 0.02 g/L. The developed microfluidic paper-based device for iron detection exhibited a low detection limit (0.00090 g/L), good selectivity, and acceptable recovery. Key words: microfluidic paper-based device, spray painting, colorimetry, iron. Nous avons mis au point une nouvelle technique de pulverisation de peinture simple et peu couteuse pour fabriquer des dispositifs microfluidiques a base de papier. A l'aide ces dispositifs, nous avons employe de la peinture en aerosol pour fabriquer des barrieres hydrophobes et, au moyen d'un poincon, nous avons pu obtenir des couches a motifs en papier et des rondelles de papier sans avoir recours a des instruments specialises (p. ex., sans dispositif de coupe au laser). Tout le processus de fabrication est extremement simple, rapide et peu couteux, ce qui permet son application a grande echelle. Par ailleurs, nous avons demontre l'application du dispositif a la detection du fer. Nous avons observe une relation lineaire entre l'intensite de la couleur et la concentration du fer dans l'intervalle de 0 a 0,02 g/L. Le dispositif microfluidique a base de papier employe applique a la detection du fer a montre une faible limite de detection (0,00090 g/L), une bonne selectivite et un taux de recuperation acceptable. [Traduit par la Redaction] Mots-cles : dispositif microfluidique a papier, peinture en aerosol, colorimetrie, fer., Introduction Microfluidic paper-based analytical devices ([mu]PADs) have emerged at the intersection of engineering, physics, chemistry, biochemistry, nanotechnology, and biotechnology, with practical applications in the design of systems in which low [...]

An ion-selective potentiometric sensor with an ionophore is developed based on the ion associate of artificial food colorant E133 and a cetylpyridinium cation. The main electroanalytical parameters of the sensor are evaluated: linearity range of the response, pH effect, and the effect of temperature on the electrode performance and selectivity. The sensor is used to determine E133 in the Powerade beverage. The accuracy of the determination is confirmed by an extraction-photometric method. Keywords: ion-selective potentiometric sensor, E133 colorant, Powerade beverage DOI: 10.1134/S1061934811010139, Artificial food colorants (AFCs) are widely used in the production of foods (beverages, confectionery, sweets, etc.) to give them necessary consumer properties [1]. The use of AFCs is based on [...]

Abstract: The present work describes the design and synthesis of simple colorimetric chemosensors based on Schiff-base for highly selective sensing of cyanide and fluoride ions. The chemosensor S2, containing an [...]

Cabergoline (CAB) is an ergot alkaloid derivative with dopamine agonist activity. In this work for the first time the electrocatalytic oxidation of CAB was carried out with nickel nanoparticles-modified carbon paste electrode using cyclic voltammetry, chronoamperometry, chronocoulometry and amperometry methods. At first, nickel nanoparticles were synthesized by non-aqueous polyol method and these nanoparticles were mixed with graphite powder to form modified carbon paste electrode. The resulting modified electrode was characterized by scanning electron microscope images. In the presence of 0.1 M NaOH a good redox behavior of the Ni(III)/Ni(n) couple at the surface of the electrode can be observed. CAB was successfully oxidized at the surface of the modified electrode. The electrocatalytic oxidation peak current of this drug was linearly dependent on its concentration. The proposed sensor exhibited a high sensitivity and was successfully applied for the determination of CAB in real samples. Keywords: electrocatalytic oxidation, nickel nanoparticles, non-aqueous polyol method, cabergoline DOI: 10.1134/S1061934816030126, Cabergoline 1-[(6-allyergoline-8β-yl)-carbonyl] 1-[3-(dimethylamino)propyl]-3-ethyl urea (Scheme) is a dopamine agonist licensed for the treatment of Parkinson's disease as adjunctive treatment with levodopa plus a dopa-decarboxylase inhibitor in patients effected by on-off [...]

The main analytical characteristics of electrical, electrochemical, and thermometric sensors in the detection of vapors and traces of explosives and accompanying substances are compared. The limits of detection, sensitivity, sensor setting time (response speed) and, recovery time after exposure to analytes, and the selectivity of sensors are discussed. The efficiency of using nanodimensional structures in the sensing elements of sensors is investigated. Keywords: explosives, electrical, electrochemical, and thermometric sensors, nanostructured sensing element DOI: 10.1134/S1061934816030023, Electrical, electrochemical, and thermometric sensors are promising gas-analytical devices for the detection of explosives and accompanying substances (EASs) [1-3], especially using nanodimensional structures [4, 5]. The prospects of these sensors [...]

A colorimetric sensor is proposed for the determination of cobalt. It is prepared by immobilizing 1-(2-pyridylazo)-2-naphthol (PAN) in an optically transparent polymethacrylate matrix. The conditions for determining cobalt by the proposed colorimetric sensor are found in the study of the complexation of cobalt with a PAN-modified polymethacrylate matrix. The determination is based on the interaction of the sensor with a cobalt solution at pH 4 for 5 min, followed by the measurement of absorbance at 620 nm. The sensor ensures the determination of 0.05-0.50 mg/L of cobalt with the detection limit 0.03 mg/L. It is demonstrated that the sensor can be used for the determination of cobalt in the Cyanocobalamin medical preparation and potable water. Keywords: cobalt, immobilized reagent, polymethacrylate matrix, colorimetric sensor, solid-phase spectrophotometry DOI: 10.1134/S1061934815120060, Cobalt is a vital trace element with potential toxicity; the strict control of its concentration in the environment is required. Cobalt is a part of vitamin [B.sub.12] (cyanocobalamin), which is [...]

A microfluidic system of capillary electrophoresis with electrochemical detection is developed. The process of manufacturing a chip based on polydimethylsiloxane and glass for the determination of electroactive compounds is described. We studied the possibilities of the treatment of the chip channel surface in a gas discharge with sodium dodecyl sulfate, sodium deoxycholate, and an ionic liquid of 1-dodecyl-3-trimethylimidazolium chloride, used as additives to the background electrolyte. It was found that the developed microfluidic system can be used for the determination of polyphenolic antioxidants in green tea and red wine. Keywords: microfluidic systems, capillary electrophoresis, amperometric detection, polyphenolic antioxidants DOI: 10.1134/S1061934815060118, The number of developments in microfluidic analytical systems (MFAS) is actively growing. The advantages of MFAS are rapidity, low consumption of samples and reagents, portable equipment, and the relative simplicity [...]