Alvaro Colina

Alvaro Colina
Universidad de Burgos | UBU · Department of Chemistry

About

79
Publications
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1,194
Citations
Citations since 2017
33 Research Items
699 Citations
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
Introduction
Skills and Expertise

Publications

Publications (79)
Article
Clopyralid is a common herbicide used all around the world that can be dissolved in the rain stream and accumulate in underground water with the potential threat of reaching drinking water. Many methodologies have been proposed to perform quantitative analysis of this compound but, to this day, no Raman detection of clopyralid has been carried out....
Article
Full-text available
Molybdenum disulfide (MoS2) has attracted great attention for its unique chemical and physical properties. The applications of this transition metal dichalcogenide (TMDC) range from supercapacitors to dye-sensitized solar cells, Li-ion batteries and catalysis. This work opens new routes toward the use of electrodeposition as an easy, scalable and c...
Article
A new, simple and fast protocol to generate gold-based SERS substrates is presented in this work. Melamine is a compound widely used in the industry that can be toxic for humans if consumed even in low concentrations. EC-SERS is an excellent alternative to classical methods to detect and quantify this compound because Raman spectroscopy provides a...
Article
In the present work, a new combination of Raman and ultraviolet and visible (UV/Vis) absorption spectroelectrochemistry in reflection mode is proposed. The new experimental setup allows obtaining the two kinds of spectroscopic data without interferences concomitantly with the electrochemical information. To the best of our knowledge, it is the firs...
Article
Full-text available
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...
Article
Full-text available
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...
Article
One of the main characteristic of Analytical Chemistry is a constant searching for new methodologies to overcome analytical problems. Minimization of analysis time and sample volumes, replacement of extensive extraction protocols and improvement of selectivity are common tasks in analytical research all around the world. Spectroelectrochemistry is...
Article
Time Resolved Raman spectroelectrochemistry (TR-Raman-SEC) has been used for the first time to obtain two different Raman spectra of one single analyte in the same experiment. This double detection has been accomplished thanks to the use of electrochemical surface enhanced Raman scattering (EC-SERS) and electrochemical surface oxidation enhanced Ra...
Article
Electrochemical Surface Oxidation Enhanced Raman Scattering (EC-SOERS) is a new phenomenon that provokes the enhancement of the Raman signal during the oxidation of a metal surface. Studies carried out so far indicate that carbonyl and carboxyl group are necessary to observe this phenomenon with a delocated charge being an important factor. In this...
Article
Time resolved Raman spectroelectrochemistry is a powerful technique to prepare useful Surface Enhanced Raman Scattering (SERS) substrates suitable for quantitative analysis. Moreover, following the evolution of the Raman signal with the applied potential the selection of the best conditions for the analysis is quite simple. In this work, gold SERS...
Article
Full-text available
UV/Vis absorption spectroelectrochemistry (SEC) is a multi-response technique that has been commonly used for the characterization of materials and the study of reaction mechanisms. However, it has been scarcely used for quantitative purposes. SEC allows us to obtain two analytical signals simultaneously, yielding a dual sensor in just one experime...
Article
The synthesis and application of silver microtube substrates for quantification by surface enhanced Raman spectroscopy (SERS) is presented in this work. The roughened silver microtubes were prepared by template assisted electrosynthesis method. Using rhodamine 6G as a Raman probe molecule, the silver microtubes were tested for SERS determination, d...
Article
Electrochemical Surface Oxidation Enhancement Raman Scattering (EC-SOERS) is an interesting and promising phenomenon capable of amplifying the Raman signal in a similar way to Surface Enhanced Raman Scattering (SERS), but EC-SOERS takes place during the oxidation of a silver substrate. This phenomenon was originally described for specific electroly...
Article
In this work, UV/Vis spectroelectrochemistry (SEC), in a thin-layer regime and parallel configuration, is selected to solve a complex mixture that contains dopamine (DA), ascorbic acid (AA) and uric acid (UA). These molecules, like many other biological compounds, are assuming a highly important place in analytical and biomedical fields due to the...
Article
In the present work, a new methodology which combines two different phenomena to enhance the Raman signal is used to resolve a mixture of two compounds with similar molecular structures. The use of Raman spectroelectrochemistry (Raman-SEC) allows us to collect simultaneously, with high time-resolution, the enhancement of the Raman signal of the com...
Article
In this work, a new and easy methodology to determine uric acid in relevant samples using Raman spectroelectrochemistry is presented. The spectroelectrochemistry experiment is based on the in-situ formation of a suitable substrate that enables the enhancement of the Raman signal of an analyte during the oxidation stage of a silver electrode. This p...
Article
Spectroelectrochemistry (SEC) is a set of techniques with many advantages in the study and characterization of materials. Although SEC has not yet been widely used to study quantum dots (QDs), the information extracted from SEC experiments about these nanostructures is very useful. Most of the works that use SEC to study QDs are high‐quality pieces...
Article
Spectroelectrochemistry (SEC) has been used for more than 50 years, but this set of techniques has not been widely used for quantitative analysis. For many years, no commercial instruments were available, which made very difficult to spread the use of SEC. Nowadays, only the creativity of the researchers is required to exploit the capabilities of S...
Article
Full-text available
A flexible electrode system entirely constituted by single-walled carbon nanotubes (SWCNTs) has been proposed as the sensor platform for β-nicotinamide adenine dinucleotide (NADH) detection. The performance of the device, in terms of potential at which the electrochemical process takes place, significantly improves by electrochemical functionalizat...
Article
The amount of qualitative and quantitative information provided by a UV–vis absorption spectroelectrochemistry (SEC) experiment is sometimes wasted. However, almost all electrochemical and spectroscopic data can provide valuable information. In this spirit, the main objective proposed in this work is the quantitative resolution of catechol/dopamine...
Article
In the present work, electrochemical surface oxidation enhanced Raman scattering (EC-SOERS) was studied using time resolved Raman spectroelectrochemistry. This multiresponse technique allows us to obtain dynamic information about the processes taking place during the electrochemical oxidation of a silver substrate. EC-SOERS is particularly found in...
Article
Real-time process monitoring is still relatively scarce but is fundamental to provide in-situ information about different chemical and electrochemical processes. Particularly, electrochemical filtration has received growing attention in recent years due to the wide range of applications in which it can be successfully employed. Electrochemical remo...
Article
In this work, an unexpected enhancement of the Raman signal for uric acid during the electrochemical oxidation of a silver electrode is presented. This behavior cannot be easily explained using classical models of Surface Enhanced Raman Scattering (SERS). Time resolved Raman spectroelectrochemistry is used to study this interesting process strongly...
Article
Spectroelectrochemistry studies spectral changes as a function of applied potential or current. While there is no standard experimental setup, transparent electrodes are most typically used in transmission mode. Working in reflection mode forces light across the sample twice, resulting in higher sensitivities, but in turn requires the use of highly...
Article
A spectroelectrochemistry device capable of studying different regions of an electrode surface in a strictly simultaneous way is presented in this work. It is based on two reflection probes placed in a near-normal arrangement with respect to a working electrode surface, part of which has been deliberately modified. As expected, the electrochemical...
Article
Full-text available
Surface enhanced Raman scattering (SERS) is a powerful technique based on the intensification of the Raman signal because of the interaction of a molecule with a nanostructured metal surface. Electrochemically roughened silver has been widely used as SERS substrate in the qualitative detection of analytes at the ultra-trace level. However, its pote...
Article
UV–Vis absorption thin-layer spectroelectrochemistry greatly contributes to the assessment of parameters of electron-transfer reactions by providing electrochemical and spectroscopic information obtained simultaneously in a confined space around the working electrode. In this work we present an ingenious modification of a spectroelectrochemistry de...
Article
A novel methodology to prepare sensors based on carbon nanostructures electrodes modified by metal nanoparticles is proposed. As a proof of concept, a novel bismuth nanoparticle/carbon nanofiber (Bi-NPs/CNF) electrode and a carbon nanotube (CNT)/gold nanoparticle (Au-NPs) have been developed. Bi-NPs/CNF films were prepared by 1) filtering a dispers...
Article
Janus structures represent an overwhelming member of materials with adaptable chemical and physical properties. The development of new synthesis routes has allowed the fabrication of Janus architectures with specific characteristics depending on the final applications. In the case of the membranes, the improvement of wet routes has been limited to...
Article
Bipolar electrochemistry is receiving growing attention in the last years, not only because it is an important tool for studying electron transfer processes, but also because it is really fruitful in the development of new analytical sensors. Bipolar electrodes show promising applications as a direct analytical tool since oxidation and reduction re...
Article
The research field of real samples is pretty much complicated than the study of other systems. However, the inherent advantages of UV−vis absorption spectroelectrochemistry should overcome some difficulties related to direct measurements in complex matrices. For this reason, a singular spectroelectrochemistry device has been fabricated and validate...
Article
Changes in the optical properties of Graphene Quantum Dots (GQD) during electrochemical reduction and oxidation were investigated by photoluminescence (PL) spectroelectrochemistry, which provided direct in-situ evidence of the dependence of GQD luminescence on their redox state. We demonstrated that GQD PL intensity was enhanced upon reduction (qua...
Poster
Full-text available
Spectroelectrochemistry (SEC) is a multi-response technique that allows the simultaneous observation of a physico-chemical phenomenon from different points of view. In electrochemistry, although most experiments are conducted under semi-infinite diffusion conditions, the performance of analysis under thin-layer conditions, for example a small volum...
Presentation
Spectroelectrochemistry (SEC) is a very valuable technique both in characterization of materials and the study of reaction mechanism. Here we present the combination of UV/Vis SEC with different chemometric tools to resolve complex mixtures of different biomolecules with a high interference level both in the electrochemical and the spectroscopic si...
Presentation
Spectroelectrochemistry (SEC) is a very valuable technique both in characterization of materials and the study of reaction mechanism. In time-resolved UV/Vis absorption SEC, absorbance values depend on the wavelength, the potential/time and the concentration of the analyte. Therefore, this is a trilinear technique that is very useful in quantitativ...
Article
The development of a new device based on the use of UV-vis bare optical fibers in long optical path length configuration and the measurement of the Raman response in normal arrangement allows us to perform UV-vis and Raman spectroelectrochemistry simultaneously in a single experiment. To the best of our knowledge, this is the first time that a spec...
Presentation
Full-text available
La espectroelectroquímica es una poderosa técnica que nos permite obtener, simultáneamente, la evolución electroquímica y espectroscópica de una reacción electroquímica. La posibilidad de encontrar dos compuestos químicos que presenten el mismo potencial de oxidación e idéntico espectro de absorción UV-vis es francamente difícil. Este hecho particu...
Article
Full-text available
The electrochemical reactivity of single-walled carbon nanotube (SWCNT) films, assembled at a polarisable organic/water interface, has been probed using model redox species. Electrons generated by the oxidation of organic 1,1′-dimethylferrocene (DMFc) to DMFc+ can be transferred through the assembled SWCNT layer and reduce aqueous ferricyanide (Fe(...
Article
Optically transparent electrodes (OTEs) are needed for a wide range of applications such as solar cells, printable electronics, touch screens, light emitting diodes or flexible displays. Furthermore, OTEs are required for normal transmission spectroelectrochemistry measurements to obtain simultaneously electrochemical and spectroscopic responses. T...
Article
The purpose of this work is to develop simple and reproducible ways to fabricate carbon nanofibers (CNFs) electrodes. Disposable CNFs electrodes were fabricated after filtering CNFs through polytetrafluoroethylene filters (PTFE), using directly as electrodes these filters with the CNFs film. The electrochemical behaviour of CNFs/PTFE electrodes wer...
Article
This work describes the preparation of intrinsically blue-colored, high-performance aromatic polyamides (aramids). The color was achieved by preparing a diamine monomer containing a chromogenic azadipyrromethene (ADPM) core, which after polymerizing it with commercially available m-phenyleneisophtahlamide and isophthaloyl chloride gave the blue-col...
Article
A number of renewable energy systems require an understanding and correlation of material properties and (photo)electrochemical activity on the micro to nanoscale. Among these, conducting polymer electrodes continue to be important materials. In this contribution, an ultrasensitive scanning electrochemical cell microscopy (SECCM) platform is used t...
Presentation
Full-text available
A new thin-layer optical fiber spectroelectrochemistry cell in parallel configuration has been developed with very promising results. A three-electrode system has been fabricated on a polyethylene terephthalate s upport us ing our pres s -trans fer methodology1. A very small volume of solution (around 30 μL) is needed to perform the characterizatio...
Poster
Full-text available
The use of single walled carbon nanotubes (SWCNTs) networks as material for electrodes is highly promising for electrochemical applications1. Meanwhile, spectroelectrochemistry is an in-situ auto-validated multi-response technique that studies the spectroscopic evolution of an electrochemical process. Taking as reference these two topics, the main...
Article
A really easy method to transfer commercial single-walled carbon nanotubes (SWCNTs) to different substrates is proposed. In this paper, a homogeneous transference of SWCNTs films to non-conductor and transparent supports such as polyethylene terephthalate, glass and quartz, and to conductor supports such as indium tin oxide, aluminium, highly order...
Article
Solution phase exfoliation of graphite to yield multilayer graphene is used to form transparent electrodes, when transferred to polymer substrates. The electrochemical performance of these electrodes is determined and their use as optically-transparent electrodes for spectro-electrochemical applications is described.
Article
UV–vis absorption and Raman spectroelectrochemistry have been used to study silver nanoparticle (AgNP) electrodeposition, allowing a better understanding about the metal nanoparticle (NP) formation process and its influence on the surface-enhanced Raman scattering (SERS) effect. These techniques have provided in situ information related to the synt...
Article
Full-text available
A new controlled current multipulse methodology has been developed to modify the screen-printed electrode surface with silver nanoparticles (AgNPs). Spectroelectrochemistry has provided not only information about the type of nanoparticles (NPs) deposited on the electrode surface, but also about the electrosynthesis process. Small NPs without plasmo...
Article
A new long-optical-pathway spectroelectrochemical cell for absorptometric measurements in the UV-Vis region was developed. This cell consists of two optical fibers brought face to face and fixed on the working electrode support. As a proof of concept, the spectroelectrochemical cell was applied to the determination of catechol using a press-transfe...
Article
A novel single-walled carbon nanotubes press-transfer electrodes (SW-PTEs) for microfluidic sensing is proposed. In this approach, carbon nanotubes are press-transferred on poly-methyl-methacrylate (PMMA) substrates and easily coupled to microfluidic chips and acting as the exclusive transducer in the electrochemical sensing. The detector design co...
Article
A new device to perform spectroelectrochemical measurements in the UV/visible spectral region using screen-printed electrodes has been developed. Neurotransmitter dopamine has been selected as a proof of concept of the capabilities of the new device. The results obtained have allowed us both to study the oxidation mechanism of dopamine and to carry...
Article
Spatial scanning spectroelectrochemistry is a new analytical technique that provides spectral information at different distances from an electrified liquid/liquid interface where an electrochemical process takes place. As a proof of concept, we have studied two different electrochemical processes at the electrified liquid/liquid interface: (1) Ru(b...
Article
Coating a carbon electrode surface, specifically highly oriented pyrolytic graphite (HOPG) with an ultrathin film of poly-(3,4-ethylenedioxythiophene), PEDOT, provides a support on which a high density of uniformly dispersed Pt nanoparticles (NPs) can readily be formed by electrodeposition. The NPs tend to be much smaller, have a higher surface cov...
Article
We present two novel UV–vis absorption spectroelectrochemical cells for the study of electrochemical processes at polarized liquid|liquid interfaces based on the parallel incidence of the light beam with respect to the interface. The first one is a crude design (Cell 1) based on an existing cylindrical cell for liquid|liquid electrochemistry. The s...
Article
Full-text available
We present a fast and effective electrochemical method to purify random networks of single-walled carbon nanotubes (SWCNTs) that leads to total removal of metal catalyst without apparent detrimental effect on the electrochemical properties of the electrodes. The efficiency of the electrochemical purification has been compared with that of conventio...
Article
Full-text available
We present a simple and reproducible method to produce single-walled carbon nanotube (SWCNT) optically transparent electrodes (OTEs) for optical transmission spectroelectrochemistry on flexible and insulating Polyethylene terephthalate (PET) supports. SWCNTs grown by aerosol chemical vapor deposition (CVD) and collected directly from the gas phase...
Article
Full-text available
A new composite material based on the electrochemical generation of a layer-by-layer structure of polyaniline (PANI) and Pt particles has been prepared. The number of layers and the nature of the external layer (PANI or Pt) determine the electrocatalytic performance of the composite for the oxidation of methanol. We demonstrate that the layer-by-la...
Article
Microscopy, mass spectrometry and X-ray diffraction methods were used to analyse 415 samples of natural and archaeological flint from Sierra de Atapuerca (Burgos, Spain) in order to define the different types from Neogene and Cretaceous formations in the study area, infer their genetic context and ascertain the supply sources used by hunter-gathere...
Article
This paper shows that oligomers are retained inside the polymer film during the electrosynthesis of poly(3,4-ethylenedioxythiophene), PEDOT, in aqueous media. The behavior of the electrochemically generated PEDOT film is highly dependent on the presence of these oligomers. A detailed study of the release of oligomers trapped in the PEDOT film has b...
Article
UV-vis reflection spectroelectrochemistry has proven to be a very useful multiresponse technique to evaluate the quality of bismuth films obtained by electrochemical deposition on glassy carbon electrodes (GCEs). Bismuth films have recently emerged as a promising and environmental friendly alternative to mercury electrodes for stripping analysis. S...
Article
A new procedure for the electrosynthesis of polyaniline (PANI), based on the electropolymerization of aniline on a PANI-modified electrode, is proposed. The procedure is controlled by the chemical reaction between the aniline and the highest oxidized form of PANI. A spectroelectrochemical flow cell has been used to study the influence of the flow r...
Article
The spectroelectrochemistry of multilayer films of hexanethiolate-protected Au147 clusters (C6-Au147 MPCs) supported on gold electrodes has been investigated by UV−vis reflectance spectroelectrochemical quartz crystal microbalance in aqueous solutions containing electrolyte anions with different degrees of hydrophobicity (PF6-, ClO4-, BF4-, and NO3...
Article
The spectral changes occurring in multilayer films of hexanethiolate monolayer-protected Au147 clusters (C6–Au147 MPCs) as a consequence of quantized MPC core charging have been investigated in aqueous solutions using a multiresponse technique, UV–vis reflectance spectroelectrochemical quartz crystal microbalance (SEQCM). The joint technique, a com...
Article
UV–vis bidimensional spectroelectrochemistry has been applied to the study of the electrochemical stability of conducting polymer films during p- and n-doping processes. Specifically, poly(4,4′-bis(butylthio)-2,2′-bithiophene) has been chosen as example to prove the usefulness and suitability of this multi-response technique to characterize polymer...
Article
Bidimensional spectroelectrochemistry is an analytical technique that provides simultaneously one electrochemical and two spectroscopic signals. Taking the plane of the electrode surface as a spatial reference, normal-beam and parallel-beam UV–Vis absorbance signals are simultaneously obtained, which convey important information about the electroch...
Article
Degradation of polyaniline films electrodeposited on optically transparent gold electrodes has been followed by thin-layer bidimensional spectroelectrochemistry. The influence of the anodic potential reached during multiple potential scans has been assessed. Correlation of changes in the spectral signals in normal and parallel arrangement has enabl...
Article
A new spectroelectrochemical flow cell is presented and its capability to provide a better understanding of reaction mechanisms is illustrated with the study of the electrosynthesis and characterization of a conducting polymer, polyaniline (PANI). A spectroelectrochemical study of electropolymerization of aniline under flow conditions has been perf...
Article
Multilayer films of Au147 hexanethiolate monolayer-protected clusters (C6-Au MPCs) of 1.6-nm diameter cores were formed onto indium tin oxide electrodes and the film optical changes arising from sequential single electron removal from the MPC cores in aqueous solutions were followed by UV–vis absorption spectroelectrochemistry. The film absorbance...
Article
Quantized optical changes accompanying discrete core charging of hexanethiolate-protected Au-cluster films was evidenced by UV/Vis absorption spectroelectrochemistry. The film absorbance is found to respond proportionally and reversibly to the nanoparticle core charge in aqueous solutions (see Figure), where ion-induced rectification of the quantiz...
Article
In order to perform an in-depth study on the electropolymerization mechanism of bis(alkyl)-substituted bithiophenes, poly[4,4′-bis(metylbutylthio)-2,2′-bithiophene] (poly-MBTBT) has been electrogenerated by using both potentiodynamic and potentiostatic techniques under different experimental conditions. Bidimensional spectroelectrochemical data hav...
Article
The potentiostatic electrosynthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) in aqueous media without addition to the solution of any kind of surfactant has been studied by electrochemical quartz crystal microbalance (EQCM) and by spectroelectrochemistry. These tandem techniques have given valuable new information about the electropolymerisation...
Article
Electrogeneration of soluble Prussian Blue (PB) during the oxidation–reduction of the Fe(CN)63−/Fe(CN)64− system has been detected using bidimensional spectroelectrochemistry (BSEC). This new technique allows us to obtain simultaneously two different spectroscopic signals together with an electrochemical signal, each one containing different inform...
Article
A digital simulation model has been developed taking into account the simultaneous acquisition of one electrical and two spectroscopic signals generated in a bidimensional spectroelectrochemistry experiment. In this type of measurements, light absorption is simultaneously considered in both the normal and parallel directions to a plane electrode su...
Article
Hexacyanoferrate(III)/(II) system has been studied by UV-visible long-pathway spectroelectrochemistry. Three different methodologies, based on potentiodynamic techniques, have been successfully used in the thermodynamic characterization of the system. Formation of soluble Prussian Blue has been detected during the electrode process. The values of t...
Article
Bidimensional chronoabsorptometry is a novel spectroelectrochemical technique that monitors simultaneously three different signals: current and absorbance both normal to the electrode plane and parallel to this plane during a time in which a fixed potential is imposed. This technique is applied in the visible range to the study of the electropolyme...
Article
The electropolymerization mechanism of 4,4′-bis(butylthio)-2,2′-bithiophene (1) was studied by means of bidimensional spectroelectrochemistry. Simultaneous electrochemical and spectroscopic signals were analyzed with the aim of obtaining information about the role of the low-molecular-weight oligomers in the polymerization process. Experiments in e...

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Projects

Projects (2)
Archived project
The aim of the project is to develop and test a new compact equipment to carry out raman measurements in situ under potential control. The final goal is to offer a compact equipment to be used as a rutinary analytical tool for many systems at industrial, clinical and research fields.
Project
Preparation of Janus membranes of large effective surface and nanometric thickness exhibiting different functionality at both sides.