An Organic/Inorganic Hybrid Membrane as a Solid “Turn-On” Fluorescent Chemosensor for Coenzyme A (CoA), Cysteine (Cys), and Glutathione (GSH) in Aqueous Media

The preparation of a fluorogenic sensory material for the detection of biomolecules is described. Strategic functionalisation and copolymerisation of a water insoluble organic sensory molecule with hydrophilic comonomers yielded a crosslinked, water-swellable, easy-to-manipulate solid system for water ‘‘dip-in’’ fluorogenic coenzyme A, cysteine, and glutathione detection by means of host-guest interactions. The sensory material was a membrane with gel-like behaviour, which exhibits a change in fluorescence behaviour upon swelling with a water solution of the target molecules. The membrane follows a “turn-on” pattern, which permits the titration of the abovementioned biomolecules. In this way, the water insoluble sensing motif can be exploited in aqueous media. The sensory motif within the membrane is a chemically anchored piperazinedione-derivative with a weakly bound Hg(II). The response is caused by the displacement of the cation from the membrane due to a stronger complexation with the biomolecules, thus releasing the fluorescent sensory moieties within the membraneSpanish Ministerio de Ciencia e Innovación—Feder (MAT2011-22544) and by the Junta de Castilla y León (BU001A10-2

Polymeric chemosensor for the colorimetric determination of the total polyphenol index (TPI) in wines

We have developed a new method for the rapid and inexpensive determination of the total polyphenol index (TPI) in wines by simply immersing our sensory film in red or white wines and visually checking the colour change (qualitative analysis) or by analysing a photo taken of the film with a smartphone (quantitative analysis). This sensory material is straightforward and inexpensively prepared; it requires no monomer synthesis, is based on 100% commercially available monomers, and contains benzenediazonium salt motifs, which in the presence of phenols and/or polyphenol-based structures produce coloured diazo compounds. These sensory motifs are chemically anchored to the polymeric structure, and, accordingly, no migration of organic substances from the material occurs in the sensing process. Our method needs neither reagents nor sample pretreatment and has been contrasted with the standard TPI determination, i.e., measuring the absorbance of diluted wine at 280 nm, obtaining reliable data for white and red wines.Fondo Europeo de Desarrollo Regional and both the Spanish Agencia Estatal de Investigación (MAT2017-84501-R) and the Consejería de Educación, Junta de Castilla y León (BU306P18

Zn(II) detection in biological samples with a smart sensory polymer

We have developed a new sensory material for the rapid and inexpensive determination of Zn(II), and we have carried out a proof of concept for the determination of Zn(II) in biological samples. The interaction with Zn(II) generates an OFF-ON fluorescence process on the material, which can be recorded both with a fluorimeter and with a smartphone by analyzing the RGB components of the taken photographs. This sensory material is prepared with 99.75% of commercially available monomers and contains 0.25% of a sensory monomer based on a quinoline structure. The sensory motifs are chemically anchored to the polymeric structure, and, accordingly, no migration of organic substances from the material occurs during the sensing process. Our method has been tested with freshly prepared Zn(II) aqueous solutions, but also with biological samples from exudates of chronic wounds. The proposed methodology provides limits of detection (LOD) of 13 and 27 ppb when employing a water-soluble polymer (WsP) and a hydrophilic polymeric film (HP), respectively, using emission spectroscopy. The measurements have been contrasted with ICP-MS as the reference method, obtaining reliable data. This study is the starting point toward a larger investigation with patients, which will address the challenge of establishing a direct relationship between the concentration of zinc(II), other cations and also of amino acids, with the protease activity and, finally, with the state/evolution of chronic wounds. In this context, the proposed sensory material and others we are now working with will act as a simple and cheap method for this purpose.FEDER (Fondo Europeo de Desarrollo Regional), and both the Spanish Ministerio de Economía, Industria y Competitividad (MAT2017-84501-R) and the Consejería de Educación—Junta de Castilla y León (BU061U16

Why is the Sensory Response of Organic Probes within a Polymer Film Different in Solution and in the Solid-State? Evidence and Application to the Detection of Amino Acids in Human Chronic Wounds

We anchored a colourimetric probe, comprising a complex containing copper (Cu(II)) and a dye, to a polymer matrix obtaining film‐shaped chemosensors with induced selectivity toward glycine. This sensory material is exploited in the selectivity detection of glycine in complex mixtures of amino acids mimicking elastin, collagen and epidermis, and also in following the protease activity in a beefsteak and chronic human wounds. We use the term inducing because the probe in solution is not selective toward any amino acid and we get selectivity toward glycine using the solid‐state. Overall, we found that the chemical behaviour of a chemical probe can be entirely changed by changing its chemical environment. Regarding its behaviour in solution, this change has been achieved by isolating the probe by anchoring the motifs in a polymer matrix, in an amorphous state, avoiding the interaction of one sensory motif with another. Moreover, this selectivity change can be further tuned because of the effectiveness of the transport of targets both by the physical nature of the interface of the polymer matrix/solution, where the target chemicals are dissolved, for instance, and inside the matrix where the recognition takes place. The interest in chronic human wounds is related to the fact that our methods are rapid and inexpensive, and also considering that the protease activity can correlate with the evolution of chronic wounds.FEDER (Fondo Europeo de Desarrollo Regional), and both the Spanish Ministerio de Economía, Industria y Competitividad (MAT2017‐84501‐R) and the Consejería de Educación—Junta de Castilla y León (BU061U16

Colorimetric detection and determination of Fe(III), Co(II), Cu(II) and Sn(II) in aqueous media by acrylic polymers with pendant terpyridine motifs

Colorimetric cation responsive water soluble polymers and manageable films or membranes have beendesigned. The sensory materials respond with a colour change to the presence in water of Fe(III), Co(II),Cu(II), and Sn(II). The colour change is specific of each metal cation, and enables its identification (purplefor iron, orange for cobalt, green for copper, and yellow for tin). The design of the materials relies onan addition monomer having a terpyridine moiety, which behaves as a dye in presence of transitionmetal cations due to its proven chelating capability towards these species and the colour developmentthat always accompany the metallic complex formation. Water solutions of the sensory linear polymersallow for the UV/vis titration of Fe(III), Co(II), Cu(II), and Sn(II) with a limit of detection of 1.3 × 10−7,6.4 × 10−8, 1.3 × 10−5and 1.4 × 10−5M, respectively. On the other hand, sensory kits, cut from sensorymembranes, permitted the visual quantification of the cations in a dynamic range of five decades (1 × 10−7to 5 × 10−3M) for Fe(III) and Co(II) and of two decades (9 × 10−5to 9 × 10−3M) for Cu(II) and Sn(II).Titration curves can also be drawn from a picture taken to the sensory kits with a smartphone, by usingthe digital colour definition of the materials as analytical signal. Also, after entering into contact withhands, shapes of metallic objects (iron and cobalt containing tools) can be colour revealed by pressingthe hands on paper or cotton fabrics wetted with water solutions of the linear sensory polymer.Spanish Ministerio deEconomía y Competitividad-Feder (MAT2014-54137-R

Polímeros inteligentes para la detección rápida, sencilla y de bajo coste de nitritos en muestras de carne procesada

Los nitritos son aditivos muy utilizados en alimentación, principalmente en productos cárnicos crudos curados y cocidos. Se emplean para prolongar su vida útil, debido a que inhiben el crecimiento de diversos patógenos, destacando su acción sobre la bacteria Clostridium botulinum. La legislación actual establece la cantidad permitida de nitritos en matrices alimentarias de origen cárnico, por lo que su cuantificación es necesaria. Sin embargo, el método de análisis de este grupo de especies resulta tedioso y supone un coste económico y de tiempo muy elevado. Por ello, en este trabajo se describe un nuevo método de análisis basado en un polímero inteligente, concretamente en un sensor colorimétrico para la detección de nitritos en muestras de carne procesada. Este material permite determinar la concentración de estos aditivos a partir del cambio de color del propio material sensor al contacto directo con la matriz alimentaria. Esta variación cromática se puede analizar de manera rápida y sencilla a partir de una simple fotografía tomada con la cámara de un teléfono al polímero sensor. Además, se ha desarrollado una aplicación para teléfonos inteligentes que facilita todo el proceso, obteniendo directamente el resultado de la concentración de nitritos que contiene el producto a partir de la mencionada fotografía. El nuevo método de análisis se ha validado comparando los resultados obtenidos con un método de referencia (ISO 2918: 1975). Esta validación se ha llevado a cabo analizando 26 muestras de productos cárnicos de diferente naturaleza y procedencia (8 de ellas corresponden a jamones cocidos de elaboración propia en las instalaciones de la Universidad de Burgos, con concentraciones conocidas de nitritos, y otras 18 son muestras comerciales de concentraciones de nitritos desconocidas, entre las que se encuentran carnes frescas envasadas, jamones y salchichas cocidos). Como resultado principal, cabe indicar que no se han observado diferencias estadísticas significativas entre los resultados obtenidos con el método de referencia de medida de nitritos y el nuevo método que se propone en este trabajo, por lo que se puede considerar como una alternativa viable que supone un ahorro significadito de costes y de tiempo

La interdisciplinariedad y el itinerario curricular elegido por el estudiante, ejes fundamentales para desarrollar competencias curriculares en Química

Póster presentado en: V Jornadas de Innovación Docente de la UBU, Burgos, 21-22 de octubre de 2010, organizadas por el Instituto de Formación e Innovación Educativa-IFIE de la Universidad de Burgo

Dataset of the work "Democratization of copper analysis in grape must following a polymer-based lab-on-a-chip approach"

The dataset contains all raw data of the work "Democratization of copper analysis in grape must following a polymer-based lab-on-a-chip approach"This work was supported by the Regional Government of Castilla y León (Junta de Castilla y León) and by the Ministry of Science and Innovation MICIN and the European Union NextGenerationEU PRTR. Author Jose Miguel García received grant PID2020-113264RB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”

Heat Capacity Behavior and Structure of Alkan-1-ol/Alkylbenzoate Binary Solvents

Heat capacities for the binary mixtures of methanol with (C1–C4) alkylbenzoates and methylbenzoate with (C1–C11) alkan-1-ols have been measured over the whole composition range at 298.15 K under atmospheric pressure. From the experimental measurements, the derived excess molar heat capacities and partial excess molar heat capacities at infinite dilution have been calculated. A Redlich–Kister-type equation was fitted to these data, and the fitting parameters and standard deviations have been evaluated. Likewise, the IR spectra for the same systems have been recorded as a function of composition. The sets of experimental data gathered contribute to shed light onto the solvent structure and the underlying molecular interactions between the mixture constituents. The conclusions drawn have been established in terms of solute–solvent and solvent–solvent interactions and the ensuing structural effects between the solvent constituents.The financial support by Junta de Castilla y León, Project GR257, Ministerio de Educación y Ciencia, Project CTQ2009-13051/BQU, supported by FEDER, and Universidad de Burgos with funding by Caja de Burgos, Spain is gratefully acknowledged

Microwave Dielectric Relaxation Spectroscopy Study of Alkan-1-ol/Alkylbenzoate Binary Solvents

The structure and dynamics of alkan-1-ol/alkylbenzoate binary mixtures have been studied by microwave dielectric relaxation spectroscopy in the 200 MHz to 20 GHz frequency range. The binary mixtures of methanol, ethanol, propan-1-ol, butan-1-ol, and pentan-1-ol with methyl, ethyl, propyl, and butyl benzoates were studied at 298.15 K. The relaxational response of the pure alcohols, pure esters, and their binary mixtures over the full composition range is properly described by the Havriliak–Negami model. The alcohol content, alcohol length, and alkyl side-chain effects on the relaxational properties have been studied for these mixtures over the whole composition range. From the experimental readings, the effective and the corrective Kirkwood and Bruggeman correlation factors have been calculated. The data gathered have been interpreted in terms of the alkyl side-chain effect and their reliance on the mixture composition.The financial support by Junta de Castilla y León, Fondo Social Europeo, Project BU-299A12-1 is gratefully acknowledged