Julia Arcos

University of Burgos | UBU · Department of Chemistry

Fentanyl is a powerful synthetic opioid used to treat severe pain. New administration routes toward its illegal consumption for recreational purposes pose a growing threat to public health, either due to misuse or abuse of this substance. As a result, the rapid qualitative and quantitative determination of fentanyl in biofluids is of great interest...

Reliable identification of fentanyl and fentanyl analogs present in seized drug samples is imperative to the safety of first responders and laboratory personnel and informs the future analysis process and handling procedures. The electrochemical-surface enhanced Raman spectroscopy (EC-SERS) method developed in this work allows the in-situ preparati...

The synthetic cathinones mephedrone (4-MMC) and 4-methylethcathinone (4-MEC) are two designer drugs that represent the rise and fall effect of this drug category within the stimulants market and are still available in several countries around the world. As a result, the qualitative and quantitative determination of ‘legal highs’, and their mixtures...

Square-wave adsorptive stripping voltammetry (SWAdSV) is proposed as a fast, simple, and sensitive approach toward the detection, identification, and semi-quantitation of fentanyl in seized drug samples using screen-printed carbon electrodes. Electrochemical oxidation of fentanyl resulted in the formation of two anodic peaks, one at 0.75 V (peak I)...

Lactate oxidase (LOx), recognized to selectively catalyze the lactate oxidation in complex matrices, has been highlighted as preferable biorecognition element for the development of lactate biosensors. In a previous work, we have demonstrated that LOx crosslinking on a modified screen-printed electrode results in a dual range lactate biosensor, wit...

The performance of several MF and UF ceramic membranes that filter the seawater surrounding mussel rafts is studied for preventive detection of toxic episodes. The modified fouling index applied to UF membranes (MFI-UF) is used to compare fouling rates and membrane fouling levels. The reduction of several quality parameters such as turbidity, alkal...

The World Health Organization considers iodide deficiency diseases (IDD) to be a public health problem. The main indicator to access IDD is urinary iodide, since approximately 90% of the ingested iodide uses this clearance path, with urine being a preferable target for the analysis. In this work, two screen-printed carbon electrode (SPCE) based sen...

A new and selective voltammetric method for chloride determination is proposed, based on platinum and chloride interactions. A screen-printed platinum electrode (SPPtE) functions as a sensing platform, which promotes the formation of chloro-adsorbed species on the electrode surface, acting as an effective means of anion-determination in several mat...

The demand for bromide determination has increased over recent years. Sources of bromide contamination can be found in brines from hydraulic fracturing, pesticides and brominated polymers. Widely used in different applications, the bromide anion is present in the composition of several compounds. In this paper, we present a new selective voltammetr...

The monitoring of marine dinophysistoxin okadaic acid in seawater can serve as an early alert system for preventing the potential negative effects this toxin can have on the food industry and human health in general. A disposable sensor system for electrochemical detection of this toxin has been developed using screen-printed electrodes. The method...

Lactate concentration is studied as an indicator of physical performance in sports activities, and is also analyzed in health care applications, as well as in the food and cosmetic industries. This organic acid is routinely determined in different concentration ranges, depending on the type of samples for analysis. This paper describes the developm...

Human cytomegalovirus (HCMV) is a herpes virus that can cause severe infections or even be fatal in immunosuppressed individuals, or those with immature immune system. The available methods for its diagnostic, usually through detection of antibodies in specimens, have the main disadvantage of requiring long time to be performed. In this work, a sim...

An anodic stripping voltammetric method is reported in this study for the determination of sub-nanomolar Pb concentration using disposable sensors, each consisting of three (counter, working and reference) screen-printed electrodes. Sensor performance was optimized for the determination of Pb through several surface modifications, by using single-w...

This work reports a simple voltammetric method for the determination of chloride, bromide, and iodide ions using screen-printed carbon electrodes modified with silver nanoparticles electrochemically deposited on the working electrode surface. UV/Vis absorption spectroelectrochemistry was used to study the electrodeposition of silver nanoparticles o...

This paper shows the ability of simple modified screen-printed devices for the electrochemical detection of ascorbic acid in different samples, including serum samples. Even if the presence of uric acid does not greatly affect the analysis of ascorbic acid using screen-printed carbon electrodes modified by gold nanoparticles, dopamine must be consi...

This work describes the development of a disposable and wearable screen-printed electrochemical sensor for the determination of chloride ions. The sensor includes three screen-printed electrodes: a working, an auxiliary (both carbon paste electrodes), and an Ag/AgCl pseudo-reference electrode. The sensor works by measuring the Nernstian shift of th...

A nanofiltration (NF) process applied to both single solutes (charged and uncharged) and electrolyte mixtures formed by a dominant salt and trace ions was evaluated in this work. Experiments were performed in a pilot plant using a 200 Da cut-off spiral-wound polymeric membrane. The marked differences in rejection of the same trace ion in the presen...

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme superoxide dismutase has been developed. The oxidation signal of epinephrine substrate was affected by the presence of Al(III) ions leading to a decrease in its amperometric current. The immobilization of the enzyme was performed with glutaraldehyd...

This work describes the development of a new, simple and inexpensive method for the determination of chloride ions, by using voltammetric disposable sensors. The sensor includes three screen printed electrodes: a working, an auxiliary (both carbon based paste electrodes), and a pseudo-reference Ag/AgCl paste based electrode. Since the presence of c...

A disposable electrodic system consisting of two working electrodes connected in array mode has been developed for the simultaneous determination of histamine (His) and putrescine (Put). Histamine deshydrogenase and putrescine oxidase enzymes were respectively immobilized by crosslinking on each working screen-printed electrode, both modified with...

This paper describes the voltammetric study of the electrochemical oxidation of the antiretroviral drug Nelfinavir using a screen-printed sensor modified with carbon nanotubes. The performance of the sensor in the determination of the drug was characterized in terms of precision (RSD 5.05 %, n=5) and capability of detection (10.99±0.87 μM for α=β=0...

Cocaine is one of the most worldwide used illicit drugs. We report a magnetic particles-based enzyme-linked immunoassay (mpEIA) method for the rapid and sensitive determination of cocaine (COC) in saliva, urine and serum samples. Under optimized conditions, the limits of detections were 0.09 ng mL−1 (urine), 0.15 ng mL−1 (saliva), and 0.06 ng mL−1...

A disposable amperometric biosensor has been developed for the determination of sulfamethoxazole (SMX). Tyrosinase (TYR) has been cross-linked to screen-printed carbon electrodes previously modified by gold nanoparticles. The oxidation current recorded at +500 mV vs Ag/AgCl SPE has been related to SMX concentration. The biosensor showed an acceptab...

This work presents the simultaneous determination of cadaverine, histamine, putrescine and tyramine by square wave voltammetry using a boron-doped diamond electrode. A multivariate calibration method based on partial least square regressions has allowed the resolution of the very high overlapped voltammetric signals obtained for the analyzed biogen...

The demand for prompt, reliable and continuous control of chemical species in all analytical fields has evolved the need for small, easy to handle and inexpensive analytical sensors. Several molecules have been recognized as key analytes, among which lactic acid (LA) is of our interest. LA plays an important role in areas such as clinical diagnosis...

The selective and simultaneous amperometric determination of malic and gluconic acids was carried out using a screen-printed design with two working carbon electrodes. One of the two working electrodes was modified with gold nanoparticles, tetrathiafulvalene (TTF) and malate quinone oxido-reductase enzyme for the sensitive detection of malic acid....

Combining the advantages of the biosensor field with the problem of detecting Human Cytomegalovirus (HCMV) in human samples, an inexpensive, simple and disposable electrochemical immunosensor for glycoprotein B detection in urine is proposed. Glycoprotein B has been chosen once is the dominant antigen of HCMV. The approach is based on a sandwich-ty...

Acetylcholinesterase (ACh) and acid phosphatase (AcP) have been simultaneously cross-linked onto an array of SPCEs, which was set up by a Ag/AgCl reference electrode, a carbon counter electrode and two carbon working electrodes. The detection of As(III) and As(V) is based on their enzymatic inhibitory effect. Different immobilization conditions, su...

This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which r...

Considering the enzymatic activity of the cytochrome P450 2D6 on substrates such as codeine, the current paper includes the development of an enzymatic biosensor for detection of this drug. Home-made screen-printed electrodes were used as electrochemical transducers of the biosensor, in which the enzyme was covalently attached to the carbon surface...

Screen-printed carbon electrodes have been modified with gold nanoparticles, tetrathiafulvalene and malate quinone oxidoreductase enzyme for the sensitive and selective detection of malic acid. Amperometric experimental conditions were optimized taking into account the importance of quantifying malic acid in wine samples and the inherent complexity...

This paper describes the voltammetric determination of cocaine in presence of three different interferences that could be found in street samples using disposable sensors. The electrochemical analysis of this alkaloid can be affected by the presence of codeine, paracetamol or caffeine, whose oxidation peaks may overlap and lead to false positives....

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the pres...

Gluconate dehydrogenase (GADH) biosensors have been developed for the satisfactory determination of gluconic acid in wine samples, without any pretreatment. The biosensors have been fabricated by cross-linking immobilization of GADH onto screen-printed carbon electrodes, containing the mediator tetrathiafulvalene (TTF). Chronoamperograms have been...

Screen-printed carbon electrodes have been modified with tetrathiafulvalene and sulfite oxidase enzyme for the sensitive and selective detection of sulfite. Amperometric experimental conditions were optimized taking into account the importance of quantifying sulfite in wine samples and the inherent complexity of these samples, particularly red wine...

A chronoamperometric method for vanadium ion determination, based on the inhibition of the enzyme alkaline phosphatase, is reported. Screen-printed carbon electrodes modified with gold nanoparticles were used as transducers for the immobilization of the enzyme. The enzymatic activity over 4-nitrophenyl phosphate sodium salt is affected by vanadium...

We report on the amperometric determination of sulfite using screen-printed carbon electrodes (SPCEs) modified with gold and silver nanoparticles that were deposited on the electrode to improve the capabilities of detection. The electrode is fairly selective and responds to sulfite with an oxidation current (at 300 mV and pH 6) in the 9.80 to 83.33...

The current paper presents the chronoamperometric determination of codeine using screen-printed carbon electrodes that incorporate tetrathiafulvalene in the matrix of the working electrode, as mediator, and cross-linked acetylcholinesterase. Applying a potential of +250mV, a 1mM solution of acetylthiocholine in electrolyte solution pH 7 gives an ox...

We have developed screen-printed carbon electrodes for the determination of putrescine (Put) via the enzyme monoamine oxidase that was immobilized on the surface of the electrode by cross-linking it with bovine serum albumin using glutaraldehyde. A mixture of 5 % of tetrathiofulvalene (TTF) and carbon ink was used for the fabrication of the screen-...

We have developed screen–printed carbon electrodes for the determination of tyramine (Tyr) via plasma amine oxidase. The enzyme was immobilized on the carbon working electrode by cross–linking it with bovine serum albumin using glutaraldehyde. The employment of the mediator hydroxymethylferrocene lowers the working potential to +260 mV (vs. a scree...

A chronoamperometric assay for vanadium ions, based on the inhibition of the enzyme alkaline phosphatase, is reported. Screen-printed carbon electrodes modified with gold nanoparticles were used as transducers for the immobilization of the enzyme. The enzymatic activity over riboflavin-5-monophosphate sodium salt is affected by vanadium ions, which...

This paper describes the development of screen-printed cytochrome P450 2B4 based biosensors, from the fabrication of the device using a single screen-printing technology to its characterization and application in the determination of cocaine street samples. Voltammetric measurements were first performed in order to study the electrochemical behavio...

The work describes an amperometric bienzymatic biosensor for gluconic acid based on the coimmobilization of gluconate kinase and 6-phospho-d-gluconate dehydrogenase by crosslinking with glutaraldehyde and bovine serum albumin onto screen-printed carbon electrodes. Experimental design methodology has been used to optimize immobilization and operatio...

We report on an amperometric assay for Al(III) ions that is based on the inhibition of the enzyme α-chymotrypsin. Screen-printed carbon electrodes modified with gold nanoparticles were used as solid supports for the immobilization of the enzyme. The amperometric response of the synthetic enzyme substrate substrate N-benzoyl-L-tyrosine ethyl ester i...

The following paper describes the development of a screen-printed voltammetric pH-sensor based on graphite electrodes incorporating both internal indicator (i.e., phenanthraquinone) and reference species (i.e., dimethylferrocene). The key advantages of this type of system stem from its simplicity, low cost and ease of fabrication. More importantly,...

An enzymatic amperometric procedure for the direct measurement of As(V) in the presence of As(III) was developed. The method is based on the inhibitive action of this species on acid phosphatase enzyme (AcP) activity. Screen-printed carbon electrodes (SPCEs) were used as support for the cross-linking immobilization of the enzyme AcP. 2-Phospho-l-as...

An amperometric assay based on acetylcholinesterase (AChE) inactivation has been developed for the monitoring of permethrin using a screen-printed three-electrode system. The enzyme AChE catalyzes the hydrolysis of acetylthiocholine to thiocholine, which can be electrochemically oxidized. The presence of permethrin inhibits the AChE activity, resul...

This review summarizes the different applications of electrochemical biosensors in the determination of numerous pollutant metal ions. For this purpose, enzymes, peptides, DNA and whole cells have been used as biological components. The role of various factors affecting the analytical characteristics of biosensors, including immobilization procedur...

Screen-printed carbon electrodes (SPCEs) electrochemically platinised (Pt-SPCEs) and screen-printed platinised carbon electrodes (SPC(Pt)Es) have been chronoamperometrically characterized for the determination of formaldehyde (FA). The oxidation current registered at 600 mV in the FA concentration range from 0.99 to 9.09 mmol L(-1), led to higher p...

This work summarizes the manufacturing procedure of Horseradish peroxidase (HRP) based biosensors for the determination of the mycotoxin Ochratoxin A (OTA). The biosensors have been fabricated using the single technology of screen-printing. That is to say, an HRP containing ink has been directly screen-printed onto carbon electrodes, which offers a...

A new electrochemical method has been described and characterized for the determination of cocaine using screen-printed biosensors. The enzyme cytochrome P450 was covalently attached to screen-printed carbon electrodes. Experimental design methodology has been performed to optimize the pH and the applied potential, both variables that have an influ...

This work describes the development of a miniaturized potentiometric system comprising a miniaturized quasi-reference electrode (QRE) coupled to a solid-state ion-selective electrode (ISE) for the monitoring of pH. We describe the optimization of materials and fabrication processes including screen-printing (SP), electrode treatments (thermal and e...

Disposable screen-printed biosensors have been successfully employed in the development of analytical methods that respond to the growing need to perform rapid "in situ" analyses. Thus, the early detection of microorganisms, which plays an important role in the prevention of human health problems, animals and plants epidemics, has been carried out...

The optimization of a Differential-Pulse Stripping Voltammetry (DPSV) procedure for arsenic speciation determination, using sodium diethyldithiocarbamate (DDTC-Na) as complexing agent, is described. An experimental design methodology was used to select the optimal experimental conditions. A robust regression method was used for the calibrations und...

The measurement of antiepileptic drugs (AEDs) in different samples has received considerable attention due to the directly correlation between clinical effects and plasma concentration. Numerous methods have been extensively applied to the analysis of AEDs since many years ago providing reliable and accurate results. This paper provides an overview...

The catalytic effect of silver nanoparticles in the development of disposable screen-printed sensors for the analysis of the drug oxcarbazepine has been demonstrated. Mercury film and metallic nanoparticles modified screen-printed carbon electrodes have been tested for the analysis of oxcarbazepine using differential pulse adsorptive stripping volt...

This work reports monoamine oxidase (MAO)/horseradish peroxidase (HRP) and diamine oxidase (DAO)/horseradish peroxidase (HRP) based biosensors using screen-printed carbon electrodes for the determination of biogenic amines (BA). The enzymes have been covalently immobilized onto the carbon working electrode, previously modified by an aryl diazonium...

Enzymatic amperometric procedures for measuring arsenic, based on the inhibitive action of this metal on acetylcholinesterase enzyme activity, have been developed. Screen-printed carbon electrodes (SPCEs) were used with acetylcholinesterase covalently bonded directly to its surface. The amperometric response of acetylcholinesterase was affected by...

Enzymatic amperometric procedures for measurement of Hg (II), based on the inhibitive action of this metal on urease enzyme activity, were developed. Screen-printed carbon electrodes (SPCEs) and gold nanoparticles modified screen-printed carbon electrodes (AuNPs/SPCEs) were used as supports for the cross-linking inmobilization of the enzyme urease....

Horseradish peroxidase has been successfully immobilized in a polypyrrole matrix onto disposable screen-printed carbon electrodes for the selective detection of Ochratoxin A. The chronoamperometric determination of this mycotoxin has been optimized by experimental design methodology, which implied the join evaluation of pH of the buffer solution, a...

A new enzymatic electrochemical biosensor based on disposable transducers, namely screen-printed carbon electrodes, has been developed for the determination of the antiepileptic drug levetiracetam. Horseradish peroxidase was immobilized onto the carbon working electrode previously modified by an aryl diazonium salt. The formation of amide bonds bet...

Glassy carbon (GCE), screen-printed carbon (SPCE) and silver nanoparticle-modified carbon screen-printed (AgNPs/SPCE) electrodes are assessed in the determination of carbamazepine (CBZ) using the oxidation signal obtained from differential-pulse adsorptive stripping voltammetry (DPAdSV). Amperometric analysis of CBZ was also performed using an elec...

An easy covalent immobilization method used to develop enzyme biosensors based on carbon and gold screen printed electrodes (SPCEs and gold SPEs) is described. The linkage of biomolecules through 4-nitrobenzenediazonium tetrafluoroborate, mercaptopropionic acid and thioctic acid monolayers has been attempted using bare SPCEs and gold SPEs, as well...

This paper describes a procedure for the determination of antimony (III) by differential pulse anodic stripping voltammetry using a mercury film screen-printed electrode as the working electrode. The procedure has been optimized using experimental design methodology. Under these conditions, in terms of Residual Standard Deviation (RSD), the repeata...

This work shows an easy and fast electrochemical method for Levetiracetam (LEV) determination, which is a novel antiepileptic. Most of the methods used up to now for its determination required a pre-treatment of the sample. It is shown here that the developed Peroxidase based biosensors avoid this kind of drawbacks. Screen-printed carbon electrodes...

Carbon screen-printed electrodes (CSPEs) modified with metal nanoparticles present an interesting alternative in the determination of chromium(VI) by differential pulse voltammetry (DPV). Metallic silver and gold nanoparticle deposits have been obtained by electrochemical deposition. Scanning electron microscopy measurements show that the electroch...

Three-electrode configuration chips containing a Pt, Au and a screen-printed Ag/AgCl as counter, working and reference electrode, respectively, have been developed. Selective determination of Phenobarbital (PB) has been carried out by Cytochrome P450 2B4 (CYP450) immobilization into a polypyrrole matrix onto the gold working electrode. Chronoampero...

An application of a partial least squares calibration method for the simultaneous voltammetric determination of indomethacin, acemethacin, piroxicam and tenoxicam is suggested. It was shown that it is possible to resolve complex mixtures of analytes even when they have strongly overlapped signals. In order to check the proposed method, statistical...

A new methodology was proposed for the speciation of chromium by differential pulse adsorptive stripping voltammetry (DPAdSV) using pyrocatechol violet (PCV) and N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA) as complexing agents. In this procedure, a partial least squares (PLS) regression was used for the resolution of the strong...

A procedure for the determination of chromium by differential pulse adsorptive stripping voltammetry (DPAdSV), using ammonium pyrrolidine dithiocarbamate (APDC) as complexing agent, has been optimized. The new method allows the selective determination of Cr(VI) in the presence of Cr(III) at pH equal to or below 3. The selection of the experimental...

A procedure for the determination of chromium by differential pulse catalytic-adsorptive stripping voltammetry (DPAdSV), using N-(2-hydroxyethyl) ethylenediamine-N, N′, N′-triacetic acid (HEDTA) as complexing agent, has been optimized. The selection of the experimental conditions was made using experimental design methodology. The calibrations were...

A procedure was proposed for the speciation of chromium by differential pulse adsorptive stripping voltammetry (DPAdSV) using pyrocatechol violet (PCV) as a complexing agent. In this procedure a partial least squares regression (PLS) was used for the resolution of the strongly overlapping voltammetric signals from mixtures of CrIII and CrVI in the...

A procedure for the determination of rifamycin SV by adsorptive stripping voltammetry (AdSV) has been optimized. Two different voltammetric techniques, namely differential pulse adsorptive stripping voltammetry (DPAdSV) and square wave adsorptive stripping voltammetry (SWAdSV) were used. In order to determine the most sensitive technique, an optimi...

A procedure for the determination of chromium in wine by differential pulse adsorptive stripping voltammetry (DPAdSV), using different complexing agents (TTHA, DTPA and Cupferron), has been optimized. The selection of the experimental conditions was made using experimental design methodology. Under these conditions the calibrations were made and th...

Procedures for the determination of indomethacin and acemethacin by differential pulse adsorptive stripping voltammetry with a mercury electrode have been described and optimised. The selection and optimization of the experimental parameters was done using factorial and central composite designs. Indomethacin and acemethacin in urine were determine...

A method for the determination of nickel in wine by differential-pulse adsorptive stripping voltammetry using dimethylglyoxime as complexing agent was optimised using experimental design methodology. In order to destroy organic matter, two different methods of treating the sample were considered. The UV irradiation method was selected and optimised...

A procedure was proposed for the resolution of strongly overlapping voltammetric signals from mixtures of indomethacin and acemethacin. In this procedure a partial least squares regression (PLS) used the full voltammogram. The application of a genetic algorithm to select some of the predictor variables (potentials of the voltammogram) allows one to...

A genetic algorithm is a suitable method for selecting wavelengths for PLS (partial least squares) calibration of mixtures with almost identical spectra without loss of prediction capacity. In the calibration of acemethacin and indomethacin, the proposed procedure eliminates the matrix effect due to the solvent which causes greater variability of t...

A procedure for the determination of nickel by adsorptive stripping voltammetry (AdSV), using dimethylglyoxime as complexing agent, has been optimized. The determination was carried out by two different techniques: differential pulse adsorptive stripping voltammetry (DPAdSV) and square wave adsorptive stripping voltammetry (SWAdSV). The selection o...

Differential-pulse anodic stripping voltammetry with a mercury microelectrode was used for the determination of copper with ethylenediaminetetraacetic acid as complexing agent. Interactions between analytical factors and their optimal levels were investigated using two factorial designs and the steepest ascent method. The calibration graph, calcula...