Saturnino Ibeas

• University of Burgos

This study introduces reusable polyacrylic membranes, fabricated from commercially available monomers (1-vinyl-2-pyrrolidone and methylmethacrylate), as a promising approach for pesticide extraction. These membranes effectively remove the commonly used herbicides mecoprop (RE ≈ 99%) and bentazon (RE ≈ 95%) at low concentrations, which pose water co...

Quality control in the food industry is of the upmost importance from the food safety, organoleptic and commercial viewpoints. Accordingly, the development of in situ, rapid, and costless analytical tools is a valuable task in which we are working. Regarding this point, the copper content of grape must has to be determined by wineries along the win...

We report on an innovative method to measure the Zn(II) concentration in pet food commercial pet food samples, both wet and dry food. It is based on a colorimetric sensory polymer prepared from commercial monomers and 0.5% of a synthetic monomer having a quinoline sensory core (N-(8-(2-azidoacetamido)quinolin-5-yl)methacrylamide). We obtained the s...

We have developed an in situ methodology for determining nitrite concentration in processed meats that can also be used by unskilled personnel. It is based on a colorimetric film-shaped sensory polymer that changes its color upon contacting the meat and a mobile app that automatically calculates the manufacturing and residual nitrite concentration...

We have faced the preparation of fully water-soluble fluorescent peptide substrate with long-term environmental stability (in solution more than 35 weeks) and, accordingly, with stable results in the use of this probe in determining the activity of enzymes. We have achieved this goal by preparing a co-polymer of the commercial N -vinyl-2-pyrrolidon...

A new original application for a polyacrylic film based on the monomers 2-(dimethylamino)ethyl methacrylate (NNDA), 2-hydroxyethyl acrylate (2HEA) and methylmethacrylate (MMA) as a starch azure container has been set up for a simple determination of honey diastase activity. The proposed method is based on the correlation of reducing sugars generate...

The healing processes in cutaneous wounds, i.e., chronic wounds, represent a health problem affecting 1-2% of the population. The evaluation of these wounds is mainly based on subjective parameters, although there is a medical consensus on protease activity as the best marker for healing disorders. Here we show the correlation of the amino acid con...

Novel fluorescent solid sensors for Fe3+ detection in aqueous medium have been developed by photopolymerization of N-vinylpyrrolidone (VP), butyl acrylate (BA) and imidazolium-based ionic liquids obtained by anion change (Br-, BF4 -, TFSI- and PF6 -). The correlation between the hydrophilicity and the stability of the membranes was established, as...

We have developed a new method for the rapid (2 h) and inexpensive (materials cost < 0.02 €/sample) “2-in-1” determination of the total phenolic content (TPC) and the antioxidant activity (AOX) in honey samples. The method is based on hydrophilic colorimetric films with diazonium groups, which react with phenols rendering highly colored azo groups....

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...

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 als...

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 i...

We have prepared solid sensory materials for the visual detection of cyanide in 100% water solutions and gas phases. The materials are hybrid polymers that were prepared from a palladium-containing acrylic monomer for use as sensory films and smart textiles.

We report the development of new chemical probes for cereulide, a toxic metabolite produced by specific strains of Bacillus cereus, through displacement of potassium cations from a preformed specific complex and a subsequent change in the fluorescence emission. For this purpose, we designed fluorescent probes for potassium cations that were suitabl...

Supplementary

Colorimetric cation responsive water soluble polymers and manageable films or membranes have been designed. 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 (purple for iron, orange for cobalt, green...

Aluminium ion is believed to cause a number of neurological and skeletal disorders in human body. The study of the biological processes and molecular mechanisms that underlie these pathological disorders is rendered a difficult task due to the wide variety of complex species that result from hydrolysis of Al3+ion. In addition, this ion displays a p...

We report herein a fluorescence polymer membrane as a film-shaped solid sensory kit for the detection and quantification in water of saccharides, namely, fructose and glucose, and dopamine. The sensory motifs are phenylboronic acids, which are chemically incorporated in the polymer network in the radically initiated bulk polymerization process. The...

Selected new fluorogenic probes that interact in different ways with Hg2+ and MeHg+ have been prepared and used for the chemical speciation of both cations in aqueous solution as well as in HEK293 cells. The best selective speciation of Hg2+ and MeHg+ has been achieved by in vitro approaches based on fluorogenic probes supported in cultured cells,...

Reusable colorimetric acid responsive coated fibres and manageable films or membranes have been successfully designed and prepared herein. The design of the materials rely on condensation and addition monomers both having the azobenzene group, which is used as a dye moiety as a weak basic motif, and a N,N-dimethylamino moiety. The N,N-dimethylamino...

We have designed and successfully prepared polymer membranes as manageable films for colourimetric sensory materials for the visual detection of the acidity of water in the low pH range, below 4, and beyond the pH scale, up to a concentration of perchloric acid of 11.6 M. For this purpose, two monomers with weakly basic groups were synthesised, wit...

Selective and sensitive solid sensory substrates for detecting Al(III) in pure water are reported. The material is a flexible polymer film that can be handled and exhibits gel behavior and membrane performance. The film features a chemically anchored salicylaldehyde benzoylhydrazone derivative as an aluminum ion fluorescence sensor. A novel procedu...

A solid substrate comprised of a cross-linked polymer network is shaped as a film with gel-like behaviour and is used to detect aluminium ions in water; concurrently, a water soluble sensory polymer synthesised toward the same purpose is also discussed. The detection in both systems was achieved via fluorescence “turn-on”. The limits of detection f...

Solid polymer and metallogel networks based on a fluorene derivative as fluorescent and colourimetric chemosensors for Hg(II), Reactive & Functional Polymers (2014), doi: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manus...

This work describes two sensing systems for the detection and quantification of Hg(II): a) a highly tractable solid polymer membrane, and b) a gelling system based on a low molecular weight gelator. The preparation of both sensory systems relies on a polymerisable acrylic monomer derived from a fluorene core containing a functional hydroxyimino gro...

Solid polymer and metallogel networks based on a fluorene derivative as fluorescent and colourimetric chemosensors for Hg(II), Reactive & Functional Polymers (2014), doi: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manus...

We have prepared a solid sensory polymer kit to detect and quantify the water in organic solvents, as well as the ambient humidity; these determinations are cheap, easy and rapid with our new material. The limit of detection of water is 7x10-4 % in acetone, 4x10-3 % in THF, and 3x10-4 % in toluene. Additionally, the relative humidity in air can be...

Iron in blood serum, wine and water has been visually detected and quantified quickly by processing photographs of an iron colorimetric sensory polymer substrate. The photographs may be taken with a conventional digital camera or Smartphone. The sensory materials were designed following a straightforward strategy. A proven iron organic chelator was...

The structure and dynamics of alkan-1-ol/alkylbenzoate binary mixtures have been studied by microwave dielectric relaxation spectroscopy in the 200 MHz-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 re...

TITLE: Study of Some Complexation Reactions in the Design and Synthesis of New Hybrid Polymeric Materials

Metal Complexes

A water-insoluble organic chemosensor has been chemically modified by introducing a polymerizable methacrylamide moiety via copolymerization with a hydrophilic comonomer (vinylpyrrolidone), producing a water-soluble acrylic copolymer that is able to sense environmentally poisonous cations in pure aqueous media. The chemosensor is a derivative of Rh...

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...

Heat capacities for the binary mixtures of methanol with (C(1)-C(4)) alkylbenzoates and methylbenzoate with (C(1)-C(11)) 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 infi...

A fluorogenic sensory film, or dense membrane, capable of detecting Cr(VI), Fe(III), and Hg(II) in water was prepared. The film was prepared by a bulk radical polymerization of different comonomers, one of which contained a piperazinedione motif as sensory fluorophore. The film exhibited gel-like behavior and was highly tractable, even after being...

We report a fluorogenic probe that is able to discriminate a range of primary or secondary biogenic amines and their natural or synthetic mimics, in water or buffer, by means of the turn-on transient generation of green fluorescence, with high quantum yields and low detection limits, thus making the system suitable for the detection of abuse drugs,...

This paper describes the preparation of a hydrophilic copolymer membrane with two comonomers: 1-vinyl-2-pyrrolidone (commercial) and a new water insoluble piperazinedione derivative, which is a fluorogenic mercury sensing motif. The dense membrane permitted the fluorogenic detection of Hg2+ in aqueous media. The sensitivity of the membrane this cat...

Linear water-soluble polymers and nets with gel-like behavior were prepared for use as colorimetric sensors and selective extracting agents for naked eye detection and solid–liquid removal of heavy-metal cations from aqueous environments. Triazole is a well-known, heavy-metal cation host. A water-insoluble methacrylamide containing a 1,2,4-triazole...

The mechanisms for the hydrolysis of organopalladium complexes [Pd(CNN)R]BF(4) (R=P(OPh)(3), PPh(3), and SC(4)H(8)) were investigated at 25 °C by using UV/Vis absorbance measurements in 10 % v/v ethanol/water mixtures containing different sulphuric acid concentrations in the 1.3-11.7 M range. In all cases, a biphasic behavior was observed with rate...

Novel colorimetric polyamide model compounds for anion-sensing applications are described. Light beige solutions of one of the models (M3) in DMSO develop a red to yellow-reddish colour upon addition of some anions, including OH-, F-, HC[image omitted], P[image omitted], AcO-, benzoate-, oxalate2- and p-toluenesulphonate-. In contrast, they remain...

The interaction of the Cu(II) drugs CuL(NO(3)) and CuL'(NO(3)) (HL is pyridine-2-carbaldehyde thiosemicarbazone and HL' is pyridine-2-carbaldehyde 4N-methylthiosemicarbazone, in water named [CuL](+) and [CuL'](+)) with [poly(dA-dT)](2), [poly(dG-dC)](2), and calf thymus (CT) DNA has been probed in aqueous solution at pH 6.0, I = 0.1 M, and T = 25 d...

The acid-catalyzed hydrolysis of the organopalladium complex [Pd(CNN)P(OMe)3]BF4 species was monitored spectrophotometrically at different sulfuric acid concentrations (3.9 and 11.0 M) in 10% v:v ethanol-water over the 25-45 degrees C temperature range and in 30% and 50% (v/v) ethanol-water at 25 degrees C. Two acidity regions (I and II) could be d...

The role of solvent effects on the thermodynamics and kinetics of the coralyne self-aggregation process has been investigated in ethanol-water mixtures of different compositions. The changes in the UV/visible spectra of coralyne and FAB/LSIMS mass spectrometry agreed well with the formation of a dimer species. 1D and 2D 1H experiments have allowed...

Experimental studies of the binding interactions of [CuL(NO(3))] and [{CuL'(NO(3))}(2)] (HL=pyridine-2-carbaldehyde thiosemicarbazone, and HL'=pyridine-2-carbaldehyde 4N-methylthiosemicarbazone) with adenine, guanine, cytosine, thymine and their mononucleotides (dNMP), 2-deoxyadenosine-5'-monophosphate, (dAMP), 2'-deoxyguanosine-5'-monophosphate, (...

The acid-base behavior and self-aggregation of salicylhydroxamic (SHA) and p-hydroxybenzohydroxamic acids (PHBHA)have been investigated by UV and 1HNMR spectroscopy, respectively. The acid-base parameters, measured in H2O at 25 degrees C and I=0.1 M, were pK1=7.56, pK2=9.85 for SHA and pK1=8.4, pK2=9.4 for PHBHA. The 1H NMR signals for salicylhydro...

The kinetics and the equilibria of Ni(II) binding to p-hydroxybenzohydroxamic acid (PHBHA) and salicylhydroxamic acid (SHA) have been investigated in an aqueous solution at 25 degrees C and I=0.2 M by the stopped-flow method. Two reaction paths involving metal binding to the neutral acid and to its anion have been observed. Concerning PHBHA, the ra...

The kinetics and equilibria of the interaction of ethidium bromide (EB) with the triple-stranded RNA, poly(rA).2poly(rU), have been investigated by stopped-flow, absorption, fluorescence, and circular dichroism methods; to properly assess the effect of the third strand on the polymer molar properties, molar volumes, adiabatic compressibilities, and...

The acid-catalyzed hydrolysis reactions of the antiinflammatory drugs indomethacin and acemethacin were investigated at 25.0 degrees C in a number of strongly concentrated perchloric acid media. The reaction rates were evaluated by UV measurements, and the intermediate species were detected by UV-vis, 1H NMR, 13C NMR, and mass spectroscopy measurem...

A theoretical and experimental study on the structure and deprotonation of benzohydroxamic acid (BHA) has been performed. Calculations at the RHF/cc-pVDZ level, refined by the B3LYP/AUG-cc-pVDZ method, indicate that, in the gas phase, Z amide is the most stable structure of both neutral and deprotonated BHA. (1)H-(1)H nuclear Overhauser enhancement...

Indomethacine (1) and acemethacine (2) contain the substituents -OCH3, -CH2COOH, -CH2COOCH2COOH, C-indole and O-benzoyl, which are susceptible to protonation in highly acidic media. To determine the protonation sites and the substituent effects reliably, the dissociation constants of the set of structurally related compounds 1-benzoyl-3-methylindol...

Protonation of the orthopalladated carbon of the cyclometallated complex [Pd(CNN)L]+, where L = P(OMe)3 and HCNN is the C-deprotonated form of the tricoordinated chelant donor ligand 2-acetylpyridinephenylhydrazone, has been studied at 25, 35, 40 and 45 °C in highly acidic 10% v∶v ethanol–water, and at 25 °C in 30% and 50% v∶v ethanol–water. The ac...

Acidity constants of benzamide and seven ortho-substituted derivatives were determined. Except for o-nitrobenzamide, all the amides exhibit medium effects. The data were treated by vector analysis. o-Aminobenzamide displays two protonation equilibria. The second acidity constant was determined by vector analysis and by the excess acidity function,...

The behavior of N-phenylbenzohydroxamic acid (PBHA) in organic solvents has been investigated by (1)H and (13)C NMR spectroscopy. Measurements in acetone at different temperatures and concentrations enable one to individualized two signals, in a 20/80 area ratio, which were ascribed to partition of PBHA between two isomers, HZ (cis) and HE (trans)....

Theoretical (ab initio calculations) and experimental (NMR, spectrophotometric, and potentiometric measurements) investigations of the isomers of acetohydroxamic acid (AHA) and their deprotonation processes have been performed. Calculations with the Gaussian 98 package, refined at the MP2(FC)/AUG-cc-pVDZ level considering the molecule isolated, ind...

The protonation equilibria of N-phenylbenzohydroxamic, benzohydroxamic, salicylhydroxamic, and N-p-tolylcinnamohydroxamic acids have been studied at 25 degrees C in concentrated sulfuric, hydrochloric, and perchloric acid media; the UV-vis spectral measurements were analyzed using the Hammett equation and the Bunnett-Olsen and excess acidity method...

The mechanism of the protonation of acetohydroxamic acid is investigated comparing experimental results and ab initio calculations. Experimentally, the UV spectral curves were recorded at different temperatures, at constant dioxane/water concentration, and at very high concentrations of strong mineral acids. The process is followed by monitoring th...

The excess acidity method was applied to rate data obtained for 2-acetylpyridinephenylhydrazone hydrolysis in strong acid media using various aqueous/organic solvents, and it was observed that the reaction rate decreases with increasing permittivity of the medium. Two hydrolysis mechanisms are indicated. Below 0.6 M H2SO4, no hydrolysis was observe...

This work presents a theoretical study of acetohydroxamic acid and its protonation processes using ab initio methodology at the MP2(FC)/cc-pdVZ level. We find the amide form more stable than the imidic tautomer by less than 1.0 kcal mol(-)(1). For comparison with the experimental data, a three-dimensional conformational study is performed on the mo...

The acid dissociation constants of some orthopalladated complexes have been determined in 10% v/v DMSO/water mixed solvent. The positive charge is located on the Pd(II) atom; in basic medium the H atom on the ligand is partially released, which convert these complexes into zwitterions. The ionization constants of the two overlapping equilibria of t...

A study of the acid-base behaviour of the three isomeric pyridinecarboxylic acids (picolinic, nicotinic and isonicotinic acid) was carried out using spectrophotometric and potentiometric measurements. The cationic form of picolinic acid converts partially into the corresponding zwitterion (pK1) within a borderline acidity range where neither the pH...

Excess viscosities and excess Gibbs energies of activation for viscous flow at five temperatures have been calculated for binary liquid mixtures of pyrrolidin-2-one with (C6–C10) alkan-1-ols from the experimental densities and viscosities of the mixed fluids. The excess viscosities and excess Gibbs energies of activation were negative, and increase...

The kinetics of the oxidation of L-ascorbic acid by hexacyanoferrate(III) ions have been investigated in strongly acidic media over a wide range of acidity. Two different mechanisms involving the monoascorbate anion, AH–, the neutral molecule of ascorbic acid AH2, and the protonated species AH+3, as well as the hexacyanoferrate(III) ion Fe(CN)3–6,...