Elisa Gonzalez-Romero

• PhD
• Full Professor at University of Vigo

This study describes the development of catalytic surface immobilizing dopamine via cross-linking or tyrosinase through covalent bonds on an electrografted screen-printed carbon electrode with a 4-nitrobenzenediazonium ion. A simple electrochemical reduction approach was used to covalently graft aryldiazonium ions onto the surface of commercial ele...

This review explores the development, technological foundations, and applications of biosensor technologies across various fields, such as medicine for disease diagnosis and monitoring, and the food industry. However, the primary focus is on their use in detecting contaminants and pathogens, as well as in environmental monitoring for water quality...

The research work presented here describes the development of catalytic surfaces immobilizing dopamine via cross-linking or tyrosinase via covalent bond on an electrografted screen-printed carbon electrode with a 4-nitrobenzenediazonium ion. A simple electrochemical reduction approach was used to graft aryldiazonium ions onto commercial electrodes,...

In this study, several materials are presented as modifiers of the screen-printed carbon electrodes with the aim of developing new sensing platforms for the voltammetric analysis of drugs. Specifically, Clotiapine and Sulfamethoxazole were selected as models for antipsychotics and antibiotics, respectively. Different nanostructures were studied as...

A novel modification of a paste carbon electrode by Bentonite (Bent) and l-Cysteine (l-Cyst) was carried out for uric acid (UA) and ascorbic acid (AA) detection and quantification. Morphological and compositional characterization of the electrode surface were carried out using electrochemical impedance spectroscopy (EIS), scanning electron microsco...

In this work, we deepen in the characterization of two protic ionic liquids (PILs), ethylammonium nitrate (EAN) and propylammonium nitrate (PAN). With this aim, we determined the influence of inorganic nitrate salts addition on their physical properties and their electrochemical potential window (EPW). Thus, experimental measurements of electrical...

Novel aryl guanidinium analogues containing the pyridazin-3(2H)-one core were proposed as minor groove binders (MGBs) with the support of molecular docking studies. The target dicationic or monocationic compounds, which show the guanidium group at different positions of the pyridazinone moiety, were synthesized using the corresponding silyl-protect...

Water quality is essential to both human and ecosystem health, and a fast detection of emerging pollutants is claimed, along with effective wastewater treatment plants to eliminate these types of substances. The goal of this study was the development of a sensitive and selective methodology to customize a handle device that meets this demand. Cloza...

In aqueous acid solution and in mixed alcohol-water solvents ([H3O+] > 10–2 M), in the dark and in the absence of reductants, the spontaneous decomposition of aryldiazonium, ArN2+, salts proceeds through borderline SN1 (DN + AN) -SN2 mechanisms. The rate constant values depend strongly on the nature of the substituents attached to the aromatic ring...

El problema que se plantea es determinar ciertos compuestos de interés en el campo del análisis clínico, que son los cationes sodio y potasio, los aniones cloruro, nitrato, sulfato y fosfato, y del grupo de los compuestos orgánicos, la creatinina y el ácido úrico, todos ellos en muestras de orina. Además, se incluyen una serie de estudios complemen...

This study presents the applicability of differential pulse voltammetry (DPV) technique to carry out in-depth research of electro-Fenton process. To this end, the degradation of the ionic liquid p-xylene-bis(n-pyridinium bromide) was performed, and the main parameters that influence this process were also evaluated. DPV allowed monitoring the evolu...

The following is a description of a simple strategy for monitoring phenolic pollutants from highly-contaminated water samples. These phenolic compounds are removed from tap water using horseradish roots (Raphanus sativus) that contain peroxidase as catalyst and H2O2 to generate hydroxyl radicals. The later (•OH) acts on the aromatic structure, caus...

We have developed a seed-mediated approach for selective growth of Au-on-Pd tetrahedral nanoparticles (NPs) giving rise to Pd-Au heteropentamers. The size of the Au domains in the heterostructures could be finely tuned from 4 to 8 nm. HRTEM characterization demonstrated that the heteromers are single crystalline indicating an epitaxial growth of Au...

El objetivo de este estudio ha sido el desarrollo de metodologías electroanalíticas para la determinación de los elementos tóxicos, plomo (Pb) y cadmio (Cd), y elementos traza esenciales, cobre (Cu) y zinc (Zn), en matrices complejas mediante Polarografía de Pulso Diferencial (DPP) y Voltamperometría de Redisolución Anódica (ASV). Se presentan dos...

Concern about the current pollution of water environments and the inefficacy of conventional water treatments for the elimination of refractory contaminants has placed electrochemistry in the spotlight. With the objective of demonstrating the diverse applications that electrochemical techniques can have in the area of water remediation, this study...

Heterogeneous electro-Fenton (HEF) is a promising technique for the remediation of polluted wastewater, since it overcomes the disadvantages of anodic oxidation and Fenton process. In the present study, HEF was preformed using iron alginate spheres as the catalyst and this treatment was applied for the degradation of two ionic liquids (ILs): 1,3-di...

Degradation of Ionic Liquids by Heterogeneous Electro-Fenton electrochemical process and monitoring by analytical techniques (HPLC, IC and Voltammetry-DPV)

In this study, the degradation of the ionic liquid (IL) 1,3-dicyclohexylbenzimidazolium chloride ([DCy6bim][Cl]) was carried out by applying an heterogeneous electro-Fenton (HEF) treatment using iron alginate spheres (FeAS) as catalyst. Initial trials were performed at current between 50 and 250 mA, different FeAS dosages (1–5 g), and [DCy6bim][Cl]...

Anyone clicking on this link before March 31, 2018 will be taken directly to the final version of this article on ScienceDirect: https://authors.elsevier.com/c/1WXPgAOM9lRhT Conventional water treatments are generally inadequate for degradation of emerging pollutants such as ionic liquids (ILs). The use of heterogeneous electro-Fenton (HEF) has at...

Fig. SM-1. Chemical structure of 1,3-Bis(2,4,6-trimethylphenyl)imidazolinium chloride ionic liquid, [IMes.HCl]IL.

Reactive Black 5 (RB5) is an electroactive diazo dye compound derivate of H-acid (coupling reaction), which cannot be effectively degraded by conventional or biological processes. In this work, the feasibility of electro-Fenton (EF) process to treat a simulated effluent polluted by RB5 dye and the effectiveness of electroanalysis by Linear Sweep Vo...

Until April 20, 2017 (free) in this link: https://authors.elsevier.com/a/1Ue5s8MvHgfloc .. "Portable screen-printed carbon electrodes (SPCEs) were uniformly modified with TiO2 and Au nanoparticles (TiO2-AuNPs-SPCE). The doped electrodes were characterized using scanning electron microscopy, X-ray photoelectron and Raman spectroscopy. Cyclic volta...

1 Equations 2 Figures S1 - S5 3Tables S1 and S2 4 Bibliography

In the last year’s, a great interest has risen for disposable electrochemical sensors for the detection of a great variety of analytes by functionalizing the electrode surface, using both coupling and electrochemical reactions (Figure), or by immobilizing enzymes, synthetic single-stranded oligonucleotides or anti-bodies onto a graphite or a gold s...

SI with 5 pages, including 1 scheme (S1), five Tables (S1 to S5) and two Figures (S1 and S2)

Binary systems of two ionic liquids (ILs), 1-ethylpyridinium methanesulfonate [C2Py][MeSO3] and choline dihydrogen phosphate [Chol][H2PO4], and water have been experimentally studied. Density, viscosity, electrical conductivity and proton activity have been measured at several temperatures covering all the miscibility range. From density data, isob...

This work illustrates, for first time, the use of simple and low-cost electroanalytical techniques to monitoring the heavy metals in microalgae cultures. The conditions of both selected techniques for the analysis, differential pulse polarography (DPP) and anodic stripping voltammetry (ASV) were optimized, giving selective and sensitive information...

The presence of emerging contaminants like ionic liquids in the environment is prompting the search of new methods to remove them from environments. To our knowledge, there are only few studies reported in the literature regarding to the application of electro-Fenton to solve this problem. Nonetheless, during the last years it has demonstrated grea...

Link: http://www.eposters.net/poster/analytical-strategies-for-monitoring-ionic-liquids-breakdown-by-electro-fenton-process Improving the framework of green chemistry principles, it should be necessary to decrease the major sources of waste as volatile organic solvent (VOS) losses that end up in the atmosphere or in ground water, mainly caused by...

This work illustrates a fast, sensitive and selective electroanalytical methodology for simultaneous determination of phenolic derivatives. Optimization of differential pulse voltammetry (DPV) conditions and electrochemical study by cyclic voltammetry (CV) of phenolics are included. Differential pulse voltammetry at screen-printed carbon electrodes...

La red de investigación BIOAUGA: BIORREMEDIACIÓN DE AGUAS DULCES CONTAMINADAS (BIOAUGA) está formada por un total de 13 grupos, pertenecientes a las tres universidades gallegas con sede en las cuatro provincias, en los campus de Ourense, Lugo, Coruña, Santiago de Compostela y Vigo. BIOAUGA pretende ser un nexo de unión entre distintos grupos, que b...

Method for Kinetic data analysis Method for characterization of SPCE surfaces by scanning electron microscopy Figures S1 - S5 Table S1

In this work, the electrocatalytic behavior of Multi-Walled carbon nanotubes screen-printed carbon electrodes (MWCNT-SPCE) towards the oxidation of phenolic derivatives tert-butylhydroquinone (TBHQ), thymol and m-Cresol is described (Figure 1). In addition, the electrochemical mechanism in the electrooxidation of phenolics for their detection is in...

The degradation of m-cresol (MC) has been investigated by heterogeneous electro-Fenton using iron loaded activated carbon (Fe-AC) as heterogeneous electro-Fenton catalyst. Experimental results demonstrated that MC was effectively removed through electro-Fenton. Calculated TOC removal and overall energy consumption showed that the use of low iron co...

Electronic supplementary information asTable S1 and Figures from S1 to S8

We report a straightforward heat treatment in air of commercial screen-printed carbon electrodes (SPCE) at different temperatures and times (ht-SPCE) that produces considerable electrocatalytic effects. The active area and the presence of oxygen groups on the ht-SPCE surface increased upon thermal treatment, more than doubling and by 20%, respectiv...

El control de contaminantes antropogénicos es un reto prioritario en la conservación del medio ambiente, sobre todo si se piensa en salvaguardar el recurso hidrológico para las generaciones venideras. Sin embargo, es un recurso extremadamente mal gestionado por las innumerables fuentes de contaminación, las cuales alteran las propiedades del mismo,...

http://www.frontiersin.org/10.3389/conf.FMARS.2014.02.00047/event_abstract

A simple strategy for covalent immobilizing DNA sequences, based on the formation of stable diazonizedconducting platforms, is described. The electrochemical reduction of 4-nitrobenzenediazonium salt ontoscreen-printed carbon electrodes (SPCE) in aqueous media gives rise to terminal grafted amino groups.The presence of primary aromatic amines allow...

Table and Figures

based on screen printed carbon electrode with immobilized 4-nitroarenediazonium-functionalized dopamine, for biosensor detection of hexacyanoferrate (III) electroactive/redox probe

We report the in situ generation of aryl diazonium cations of Azure A, a redox-active phenothiazine dye, by reaction between the corresponding aromatic aminophenyl group and sodium nitrite in 0.1M HCl. The subsequent electrochemical reduction of these dye diazonium salts gives rise to conductive electrografted films onto screen-printed carbon (SPC)...

La metodología participativa que se describe pretende ofrecer al alumno una forma de enseñanza-aprendizaje más dinámica e independiente. En ella se incorpora actividades para que éstos adquieran capacidades transversales y mejoren aspectos relacionados con las habilidades sociales que les será útil para acceder al ejercicio laboral, ya sea académic...

Contamination by cadmium in the environment is of great concern because of its toxicity and threats to human and animal health. The current study was conducted to investigate the effects of a cadmium contaminated diet on the osmoregulation and urine concentration mechanisms of the semi-desert rodent Meriones shawi and eventual accumulation of this...

This talk reports on the application of electrochemistry in emulsions and macromolecular systems in which conventional optic methods cannot be used because the dispersions are opaque. The method works equally well in homogenous surfactant solutions containing micelles and microemulsions. This methodology can be used to: 1. Monitor the change in co...

How to design a course for postgraduate students in EEES context-I How to design a course for postgraduate students in EEES context-II

The Electroanalytical Techniques applied to get insights the chemical reactivity of arendiazonium ions, ArN2+, is the topic of this research work. It describes the electrochemical reduction of ArN2+ on several electrode materials (mercury, graphite and gold) by different techniques: Differential Pulse Polarography (DPP), Linear Sweep Voltammetry (L...

Arenediazonium salts have been shown to be very important for both dyestuff industry and synthetic chemistry and substantial body of knowledge about their industrial aspects and about their use in preparative chemistry is available. The mechanism of arenediazonium reactions continue to be controversial because they vary dramatically with experiment...

The assumptions of the pseudophase model for chemical reactivity in homogeneous microemulsions are used to determine the distribution of alpha-tocopherol (TOC) in macroemulsions from changes in the observed rate constant (k(obs)) for reaction between 4-hexadecylarenediazonium ion (16-ArN2+) probe and TOC with increasing surfactant concentration. Tw...

We have investigated the dediazoniation of 4-nitrobenzenediazonium (4NBD) ions in MeOH/H2O mixtures under acidic conditions at 50 °C employing a combination of spectrophotometric and chromatographic techniques. The kinetic behaviour is quite complex; in the absence of MeOH, the dediazoniations follow first-order kinetics with a half-life t1/2 = 138...

The effects of tetradecyltrimethylammonium bromide, TTAB, and hexadecyl-trimethylammonium bromide, CTAB, micellar systems on the reaction of 3-methylbenzenediazonium, 3MBD, tetrafluoroborate with ascorbic acid, VC, and with the hydrophobic derivatives 6-O-dodecyl-L-ascorbic acid, VC12, and 6-O-palmitoyl-L-ascorbic acid, VC16, were investigated at d...

We have investigated the effects of sodium dodecyl sulfate, SDS, on the reaction between 4-nitrobenzenediazonium, 4NBD, ions and beta-cyclodextrin, beta-CD, under acidic conditions at T = 60 degrees C by employing a combination of spectrophotometric, chromatographic, and conductometric techniques. Previous studies under acidic conditions indicate t...

Dediazoniation of o-methylbenzenediazonium tetrafluoroborate was investigated in SDS/BuOH/H2O (SDS = sodium dodecyl sulfate) reverse micelles, RMs, and, for comparison, in binary BuOH/H2O mixtures by employing a combination of spectrophotometric and chromatographic techniques. RMs were characterized by steady-state fluorescence; the data indicate t...

The effects of α-, β- and γ-cyclodextrins, CDs, on the formation of sodium dodecyl sulfate micelles have been investigated by employing a conductometric method under acidic conditions. The simultaneous presence of H+ ions and Na+ ions makes the specific conductivity of the solution to follow a Z-shaped curve, which can be rationalized by considerin...

A steady-state fluorescence quenching study was undertaken to estimate aggregation numbers, N, and radii for the cell, rc, and for the water pool, rwp, of sodium dodecyl sulfate, SDS, BuOH and water reverse micelles at a fixed [H2O]/[SDS]=42.7 ratio, which allows variations in the percentage of BuOH in the system ranging 50–90%. For the purpose, py...

The effects of pH on the observed rate constants (kobsd.) and on the solvolytic dediazoniation product distributions of ethanolysis of 2-, 3-, and 4-methylbenzenediazonium ions (2MBD, 3MBD, and 4MBD, respectively) were determined by a combination of spectrophotometric (UV/Vis) and chromatographic (HPLC) techniques. The variation of both kobsd. and...

Addition of β-cyclodextrin (β-CD) to an aqueous acid solution of p-nitrobenzenediazonium (PNBD) tetrafluoroborate causes a substantial decrease in peak currents and shifts in opposite directions the apparent peak potential values, Eapp, of the -N2+> and -NO2 groups. β-CD hinders the reduction of the nitro group since Eapp(-NO2) is shifted towards m...

We have developed a new approach for estimating distributions of polar additives in opaque, surfactant based, macroemulsions based on the pseudophase model for homogeneous micellar and microemulsion solutions. The distribution of a polar additive, such as an antioxidant, AO, within emulsions is expressed in terms of two partition constants, one bet...

Addition of β-cyclodextrin (β-CD) to an aqueous acid solution of p-nitrobenzenediazonium (PNBD) tetrafluoroborate causes a substantial decrease in peak currents and shifts in opposite directions the apparent peak potential values, E a pp, of the -N2+> and -NO2 groups. β-CD hinders the reduction of the nitro group since E a pp(-NO2) is shifted tow...

The effects of ion exchange on the conductivity of SDS micellar solutions were explored by employing different amounts of HCl. An equation applicable to any acidified anionic surfactant solutions bearing monovalent, divalent, or trivalent counterions was derived allowing to estimate κ values by computer simulation procedures.

The effects of 6-O-octanoyl-L-ascorbic acid, VC8, on the reaction with 3-methylbenzenediazonium, 3MBD, tetrafluoroborate were investigated in the absence and in the presence of sodium dodecyl sulfate, SDS, cetyltrimethylammonium bromide, CTAB, and tetradecyltrimethylammonium bromide, TTAB, micelles at different pHs by employing a combination of UV-...

Chemical trapping of bromide ions by 3-methylbenzenediazonium ions, 3MBD, allowed us to investigate the effects of methanol and ethanol on the fraction of free Br- ions in water−alcohol solutions of cetyltrimethylammonium bromide, CTAB, and tetradecyltrimethylammonium bromide, TTAB, micellar systems. For the purpose, the high-performance liquid chr...

We have determined the product distribution, the rate constants for dediazoniation product formation, and the solvolytic rate constants for 2-, 3-, and 4-methylbenzenediazonium ions (2-, 3-, and 4-MBD, respectively) loss in acidic ethanol/water mixtures over the whole composition range by a combination of spectrophotometric (UV/Vis) and high perfor...

For Abstract see ChemInform Abstract in Full Text.

The effects of sodium dodecyl sulfate, SDS, micelles on the reaction between a number of arenediazonium, ArN2+, ions with hydrophilic l-ascorbic acid or vitamin C, VC, and the hydrophobic analogue 6-O-palmitoyl-l-ascorbic acid, VC16, have been investigated at different pH values. Previous results indicate that in aqueous acid solution, in the absen...

A derivatization protocol that exploits the rapid reaction between arenediazonium ions and a suitable coupling agent followed by high-performance liquid chromatography analyses of the reaction mixture was employed to determine the product distribution, the rate constants for product formation and the association constant of 4-nitrobenzenediazonium,...

The use of differential pulse polarography (DPP) at the dropping mercury electrode (DME) to detect and to investigate the mechanisms for decomposition of arenediazonium ions, ArN2+, under different experimental conditions is discussed. The effect of a number of experimental and instrumental parameters on the polarographic peaks of a model arenediaz...

The effects of sodium dodecyl sulfate, SDS, on the reductive electrochemistry of p-nitrobenzenediazonium tetrafluoroborate, PNBD, were investigated at two different pHs by employing differential pulse polarography (DPP). At pH = 2, the reduction peaks of the −N2+ and −NO2 groups are completely overlapped. Upon addition of SDS ([SDS] < critical mice...

The effects of a sodium dodecyl sulfate, SDS, micellar solution on the coupling rates of two arenediazonium ions, ArN(2)(+), with the hydrophobic 1-naphthylamine, 1NA and N-(1-naphthyl) ethylenediamine, NED, coupling agents and with the hydrophilic Na salt of 2-naphthol-6-sulfonic acid, 2N6S, have been studied. First, we explored the micellar effec...

The effects of β-cyclodextrin (CD) on the electrochemical behavior of a model arenediazonium ion were discussed. The p-nitrobenzenediazonium (PNBD) formed an inclusion complex with β-CD with the -NO2 group inside the CD cavity and the -N2+ group located outside close to the secondary hydroxyl groups of β-CD. It was found that the estimated binding...

The rate of the spontaneous decomposition of 4-methylbenzenediazonium tetrafluoroborate, 4MBD, was determined. The effects of solvent composition (MeOH/H2O) on its electrochemical processes and on those of the derivatized 2-naphthol-6-sulfonate-4-toluene (6S2NPT) azo dye were investigated by Differential Pulse Polarography (DPP). This electrochemic...

We have examined the kinetics and mechanism of dediazoniation of o-, m- and p-methylbenzenediazonium (ArN) tetrafluoroborate in the presence of ascorbic acid (H2A) at different pHs by combining spectophotometric (VIS-UV), high performance liquid chromatography (HPLC), and polarographic measurements. Kinetic data show that, at low pH, observed rate...

We have examined the kinetics and mechanisms of the dediazoniation of p-nitrobenzenediazonium tetrafluoroborate in acidic aqueous solutions by employing differential pulse polarography (DPP) and differential pulse voltammetry (DPV) on a glassy carbon electrode combined with the use of a coupling reaction to quench unreacted p-nitrobenzenediazonium...

The rates and product distribution for methoxy-, hydroxy- and hydro-dediazoniation and the rate constants for disappearance of 3- and 4-methylbenzenediazonium tetrafluoroborate in acidic MeOH/H2O mixtures, in the presence and absence of electrolytes like HCl, NaCl, and CuCl2, are reported. Data were obtained by using a combination of VIS-UV and HPL...

Most organic chemistry textbooks include sections where arenediazonium salt chemistry is discussed but this material is not normally included in undergraduate laboratory experiments. We propose an integrated physical organic experiment that includes synthesis and isolation of an arenediazonium salt in the solid state and a kinetic study of its stab...

We have examined the kinetics and mechanism of dediazoniation of p-nitrobenzenediazonium tetrafluoroborate (PNBD) in aqueous micellar solutions of sodium dodecyl sulfate (SDS) and copper dodecyl sulfate (Cu(SD)2) at different H3O+ and NaCl concentrations by combining spectrophotometric and high-performance liquid chromatography (HPLC) measurements....

Rate constants for dediazoniation product formation and arenediazonium ion loss and product yields of solvolysis of o-methylbenzenediazonium tetrafluoroborate in acidic methanol-water mixtures at T = 35°C are reported. Observed rate constants for diazonium ion loss and product formation are the same, increasing about 45% ongoing from water to metha...

A novel procedure for the determination of L-ascorbic acid (vitamin C, AA) in natural orange juice samples is described. First, we examine the kinetics of reactions of m-methylbenzenediazonium (mMBD) tetrafluoroborate in aqueous solutions. The method involves two electrochemical procedures: by directly monitoring diazonium salt loss (dediazoniation...

The rates and product distribution for the spontaneous dediazoniation of 2-, 3-, and 4-methylbenzenediazonium ions, OMBD, MMBD, and PMBD, respectively, in the presence of α-, β-, and γ-cyclodextrins (CDs) in aqueous acid are reported. No evidence of reaction between arenediazonium ions and CDs was found. Quantitative conversion to the phenol deriva...

The rates of formation and yields of products from the dediazoniation of p-nitrobenzenediazonium tetrafluoroborate (PNBD) in aqueous solutions over a range of HCl, NaCl and CuCl2 concentrations at 60 °C were examined. Two main products were observed: p-nitrophenol (ArOH) and p-nitrochlorobenzene (ArCl). Trace amounts of nitrobenzene (ArH) and p-nit...

The rates of formation and yields of products from the dediazoniation of p-nitrobenzenediazonium tetrafluoroborate (PNBD) in aqueous solutions over a range of HCl, NaCl and CuCl2 concentrations at 60°C were examined. Two main products were observed: p-nitrophenol (ArOH) and p-nitrochlorobenzene (ArCl). Trace amounts of nitrobenzene (ArH) and p-nitr...

We have measured the rates and product yields of dediazoniation of 2- and 3-methylbenzenediazonium tetrafluoroborate in the presence and absence of electrolytes like HCl, NaCl, and CuCl2 using a recently reported methodology that allows simultaneous determination of product concentrations and rates of product formation and, indirectly, loss of star...

We have examined the kinetics and mechanism of dediazoniation of 2-, 3- and 4-methylbenzenediazonium tetrafluoroborate (OMBD, MMBD, and PMBD) in aqueous micellar solutions of sodium dodecyl sulfate and copper dodecyl sulfate at two different NaCl concentrations by combining spectrophotometric and high-performance liquid chromatography (HPLC) measur...

Most writers on food either ignore scientific principles that underlie cooking or disparage the value of such information on the grounds that can not be easily reduced to the test tube. However, people who have not yet logged years preparing food might require some explanation about what is going on or just simple may be curious about what foods ar...

Foods are mixtures of different chemical compounds, and the quality we sense (taste, texture, color, etc.) are all manifestations of its chemical properties. Some of them can be visualized with the aid of simple, safe and inexpensive experiments using dairy products that can be found in any kitchen and using almost exclusively kitchen utensils. In...

The advantages which accrue from the use of metalized graphite for preparing reagentless alcohol carbon paste biosensors are described. In particular, ruthenium-dispersed graphite exhibits a marked decrease in the overvoltage for the oxidation of the liberated NADH. The ruthenium centers are integral parts of the graphite particles, thus eliminatin...

Substantial improvements in the performance of amperometric biosensors for alcohols are achieved by subjecting the glassy carbon transducer to an electrochemical pretreatment prior to the immobilization of alcohol dehydrogenase. The enzymatically generated dihydronicotinamide adenine dinucleotide (NADH) can thus be detected at a substantially (∼340...

Alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide (NAD+) have been incorporated within rigid graphite epoxy matrices to yield renewable (by polishing) alcohol sensors. The enzyme and cofactor retain their bioactivity on confinement in the graphite epoxy, with the oxidation current of the NADH formed serving as the response. Because...

An amperometric enzyme electrode for organic peroxides, based on the incorporation of horseradish peroxidase (HRP) into a carbon paste matrix, is reported. The electrode responds rapidly to low (micromolar) concentrations of such peroxides, in accordance to the following sensitivity trend: butanone peroxide > tert-butyl peroxibenzoate > cumene hydr...

Reagentless bulk-type biosensors for peroxides based on the incorporation of horse-radish peroxidase into carbon paste and graphite-epoxy matrices are described. Mediatorless detection of organic peroxides is reported for the first time. The principle of measurement is based on the electrocatalytic current arising in dependence on the peroxides lev...