Jose María Palacios Santander

Universidad de Cádiz | UCA · Department of Analytical Chemistry

The influence of thermal treatment under reducing conditions on the structural and hydrogen evolution reaction (HER) properties of Au@MoS2 structures is reported in this work. After a thermal treatment at 800 °C under H2 atmosphere, the Au@MoS2 nanostructures exhibit remarkable performance with an overpotential of 203 mV vs reversible hydrogen elec...

The separation of enantiomers plays a critical role in pharmaceutical development, ensuring therapeutic efficacy, safety, and patent protection. It enables the production of enantiopure drugs and enhances our understanding of the properties of chiral compounds. In this study, a straightforward and effective chiral detection strategy was developed f...

The authors present a novel sensing platform for a disposable electrochemical, non-enzymatic glucose sensor strip at physiological pH. The sensing material is based on dendritic gold nanostructures (AuNs) resembling feather branches, which are electrodeposited onto a laser-scribed 3D graphene electrode (LSGE). The LSGEs were fabricated via a one-st...

The chiral recognition of enantiomers is a topic of great importance. In this study, a straightforward and effective chiral detection strategy was developed for distinguishing between tryptophan (TRP) enantiomers. The approach involved the preparation of a magnetic molecularly imprinted chitosan (MMIC) for the sample preparation, which was combined...

The authors present a novel sensing platform for a disposable electrochemical, non-enzymatic glucose sensor strip at physiological pH. The sensing material is based on dendritic gold nanostructures (AuNs) resembling feather branches, which are electrodeposited onto a Laser-scribed 3D-Graphene electrode (LSGE). The LSGEs were fabricated via a one-st...

L'étape cruciale dans la création de la majorité des polymères à empreintes moléculaires (MIP) est l'élimination de l'analyte. Cette étape est difficile en raison des propriétés inhérentes du réseau polymérique et des cavités imprimées pour l'analyte. L'efficacité diminue si les MIPs contiennent encore des molécules de l'analyte, car il y a moins d...

Citation: El Hani, O.; García-Guzmán, J.J.; Palacios-Santander, J.M.; Digua, K.; Amine, A.; Gharby, S.; Cubillana-Aguilera, L. Geographical Classification of Saffron (Crocus Sativus L.) Using Total and Synchronous Fluorescence Combined with Chemometric Approaches. Foods 2023, 12, 1747. https:// Abstract: There is an increasing interest in food scie...

A new electrochemical sensor device has been developed through the modification of a polyaniline-silicon oxide network with carbon black (CB). Enhanced electrical conductivity and antifouling properties have been achieved due to the integration of this cheap nanomaterial into the bulk of the sensor. The structure of the developed material was chara...

The extraction of templates from MIPs is not an easy task as well known, because of the high affinity between monomers and templates. Herein, a new strategy for the immediate removal of the template was developed. Two polymers were prepared, one for hexavalent chromium (Cr(VI)) and the other for rutin molecule, to overcome the extraction problem fo...

In this work, the development and characterization of a new ceramic material modified with polyaniline powder obtained by a high-power ultrasound sol-gel route is presented. A preliminary screening of the conducting polymer electroactivity was performed by means of cyclic voltammetry in free analyte solution. Remarkable figures of merit for 4-chlor...

A copper-iron-based catalyst has been prepared by a low-temperature co-precipitation and sonication method. The use of high-energy ultrasound reduces the time required for the preparation process from one workweek to one day with respect to the catalysts obtained by conventional coprecipitation and thermal treatment methods. The resulting material...

In this work, the development of an electrochemical sensor for melatonin determination is presented. The sensor was based on Sonogel-Carbon electrode material (SNGCE) and Au nanoparticles (AuNPs). The low-cost and environmentally friendly SNGCE material was prepared by the ultrasound-assisted sonogel method. AuNPs were prepared by a chemical route...

Reusable Sonogel–Carbon electrodes containing carbon black (SNGC-CB) have been used for the electrochemical analysis of caffeic acid (CA) in real matrices. Measurements were firstly performed in standard solutions, in which SNGC-CB electrodes allowed the electrochemical determination of CA with high sensitivity and low limit of detection, equal to...

Monitoring of lactate is spreading from the evident clinical environment, where its role as a biomarker is notorious, to the agrifood ambit as well. In the former, lactate concentration can serve as a useful indicator of several diseases (e.g., tumour development and lactic acidosis) and a relevant value in sports performance for athletes, among ot...

In this work, a screening of Sonogel-Carbon (SNGC) electrodes modified with nanomaterials (carbon nanotubes and gold nanoparticles) and the study of their effect on the electrochemical performance of sinusoidal voltage (SV) and current (SC)-based biosensors are reported. Surface modification was achieved by drop-casting and electrodeposition method...

Tryptophan (Trp) is an essential amino acid usually found in fruit juices. Its determination is necessary for food companies because of its relation to human health. In this work, a new electrochemical method based on sonogel–carbon electrodes (SNGCEs) was developed and validated using an ultra performance liquid chromatography (UPLC) method as a r...

A novel, simple, highly sensitive and eco-friendly nanoplatform was employed for the simultaneous determination of nanoplastics, namely hydroquinone (HQ), catechol (CC), and resorcinol (RC). Indeed, the electrochemical device was based...

The development of green analytical procedures for the monitoring of several sample features is demanded by the general society and is an interesting topic investigated by the scientific community. The use of green sorbents for sampling diverse compounds before analysis in different foodstuffs, gas samples, water, and/or pharmaceutical tablets is...

A fast, precise and inexpensive alternative for evaluating the antioxidant activity (AA) in walnut kernel extracts is proposed. Traditional ABTS assay and an electrochemical index approach have been applied to evaluate the AA in walnuts. A fast and efficient defatting of the walnuts by ultrasound assisted extraction (UAE) was carried out. Later, fo...

A new theoretical approach based on density functional theory was developed to find the most suitable monomer and porogen solvent to design a specific molecularly imprinted polymer (MIP) for bisphenol-A (BPA). Various theoretical investigations were carried out including HOMO and LUMO calculation, molecular electrostatic potential of the BPA-monome...

Molecularly imprinted polymers that mimic the binding mechanism of antibodies and their antigens exhibit several advantages, such as fast synthesis, low cost, high stability, and allow to overcome the ethical issues associated with antibody farming in animals. Herein, a novel strategy combining the magnetic molecularly imprinted polymer (MMIP) as a...

A new ceramic carbon polyaniline electrode material, namely Sonogel-Carbon-polyaniline (SNG-C-PANI), was synthesized using high-power ultrasound. The synthesis conditions were optimized by means of a full factorial design. The electroactivity of polyaniline, previously characterized by means of Raman spectroscopy, is retained into the sonogel matri...

In this work, template-free nanostructured conducting polymers (nCPs)-embedded gold nanoparticles (AuNPs) from aniline, thiophene and 3,4-ethylenedioxythiophene have been prepared via a one-pot sonochemical method. The synthesis of the nanocomposite (nCPs-AuNPs) was achieved in a short period of time (5–10 min), by applying high-energy ultrasound t...

A fast and simple strategy based on the microwave technique for the preparation of magnetic molecularly imprinted polymers (MMIPs) is proposed for the selective determination of sulfamethoxazole (SMX). The MMIPs were synthesized at 70 °C in 20 min, being much faster than the conventional techniques. A computational approach based on density functio...

Magnetic nanoparticles (MNPs) uniquely combine superparamagnetic performance with dimensions that are smaller than or similar size to molecular analytes. Recently, functionalized MNPs are predicted to be a driver for technology and business in this century and hold the promise of high performance materials that will significantly influence all aspe...

This work is focused on the investigation of a composite material based on silver nanoparticles (AgNPs) and poly(3,4-ethylenedioxythiophene) (PEDOT) as sensing element of an electrochemical sensor for the determination of caffeic acid (CA). The novelties of the present work lie on the in-situ electrodeposition of AgNPs upon PEDOT layer using a sinu...

Conducting polymers (CPs) are extensively studied due to their high versatility and electrical properties, as well as their high environmental stability. Based on the above, their applications as electronic devices are promoted and constitute an interesting matter of research. This review summarizes their application in common electronic devices an...

Silica-based electrodes which permanently include a graphite/Au nanoparticles composite were tested for non-enzymatic detection of glucose and fructose. The composite material showed an effective electrocatalytic activity, to achieve the oxidation of the two analytes at quite low potential values and with good linearity. Reduced surface passivation...

Here, we describe a novel, fast, simple and green method for synthesis of gold sononanoparticles (AuSNPs) employing three different parts of Geranium (Pelargonium graveolens) extracts such as stems (AuSNPs-G.S), leaves (AuSNPs-G.L) and the mixture of both (AuSNPs-G.M), in which plant biomaterials were used as reducing and capping agents using a hig...

The present study is focused on the ultrafast and green synthesis, via the co-precipitation method, of magnetic nanoparticles (MNPs) based on iron oxides using design of experiments (DOE) and high energy sonochemical approach, considering two main factors: amplitude (energy) of the ultrasound probe and sonication time. The combination of these tech...

Herein, we report an eco-friendly electrochemical bisphenol A (BPA) sensor based on carbon black (CB) and gold sononanoparticles (AuSNPs) nanocomposite-modified Sonogel-Carbon electrode (SNGCE). The AuSNPs were synthesized by a novel green approach employing olive leaves extract and assisted by high energy ultrasound. The AuSNPs was characterized b...

During the past ten years, about 30 papers have been published on the use of polydopamine (PDA) for the preparation of molecularly imprinted polymers (MIPs). This promising polymer (PDA) still faces some challenges. The present paper reports for the first time a re-examination study of MIPs based on PDA focusing on the template removal step and its...

Molecularly imprinted polymer (MIP) composites are defined as materials composed of at least two compounds: one of them is a MIP and the other one is chosen depending on the additional properties needed for the final composites. Different materials could be coupled to MIPs, such as magnetic nanoparticles, silica particles, graphene oxide, multiwall...

A novel strategy for the preparation of reusable carbon electrode containing carbon black (CB) has been developed. CB has been introduced as the conductive and sensitive component, together with graphite, in the composite electrode material of Sonogel-Carbon (SNGC) electrodes, obtaining SNGC-CB electrodes. A complete characterization of the electro...

Chitosan is a natural polysaccharide derivative of chitin component that has been used in a wide range of fields because of their outstanding advantages, including non-toxicity, biodegradability, biocompatibility, anti-allergic, anticoagulant, antifungal and antimicrobial. Due to its excellent properties, it attracted significant attention in numer...

In this work, we present the first results obtained for the electroanalytical determination of Cannabidiol (CBD), the major non-psychoactive cannabinoid of Cannabis sativa L. plant, and Cannabinol (CBN). To this purpose, Sonogel-Carbon-PEDOT material was employed due to the high conductivity provided by poly-(3,4-ethylenedioxythiophene) (PEDOT) com...

From the beginning of the Industrial Revolution in Great Britain back on the eighteenth century, and mainly from the enormous technological development in several fields (electronics, computing, and robotics) occurred on the second half of the twentieth century that affected deeply industrial processing and manufacturing, most part of society, and...

The application of nanotechnologies to the agrifood sector provides one of the innovative tools able to support change in a system that, through its intensification and industrialization, currently fails both humans and the environment. The development of green nanotechnology, which exploits biological routes for the synthesis of nanomaterials, and...

Molecularly imprinted polymers (MIPs) are synthetic materials that mimic the natural, biological antibody-antigen systems. They operate by a “lock and key” mechanism to selectively bind the target analyte with which they were templated during production [1]. There are multiple methods to prepare MIPs including (1) surface stamping or lithography, (...

In many biological processes, the selective molecular recognition is considered as the key factor; since then, the basic principle and aim of molecularly imprinted polymers (MIPs) focused on the substitution of the natural receptors such as antibodies and enzymes by other biomimetic recognition elements based on synthetic receptors that attracted m...

The biosynthesis of ultra-small gold nanoparticles (AuNPs) with very narrow size distribution and stable dispersion through an aqueous drago (Dracaena draco L) aged leaf extract used as a non-toxic reducing and stabilizing agent has been achieved. The gold nanoparticles obtained in this way, have a size in the range 0.9–2.8 nm and an average size o...

In this work, a comparative study of the effect of various solvents on the synthesis of magnetic molecularly imprinted polymers (MMIPs) based on the use of high-power ultrasound probe is reported for the first time. Dimethylsulfoxide (DMSO), dimethylformamide (DMF), ethanol, acetonitrile and acetone were studied as solvents for the synthesis of MMI...

In this paper, we report for the first time a novel, simple and fast method for the synthesis of magnetic molecularly imprinted polymers (Mag-MIPs) based on high-energy ultrasound probe. Sulfamethoxazole (SMX) was used as template molecule, methacrylic acid as functionnal monomer, ethylene glycole dimethacrylate as crosslinking agent and magnetic n...

In this paper, we report for the first time a novel, simple and fast method for the synthesis of magnetic molecularly imprinted polymers (Mag-MIPs) based on high-energy ultrasound probe. Sulfamethoxazole (SMX) was used as template molecule, methacrylic acid as functional monomer, ethylene glycole dimethacrylate as crosslinking agent and magnetic na...

In this work, a method for the determination of phosphorus in walnuts has been developed due to the fact that there is no specific method for this purpose. A closed-vessel microwave-assisted digestion of the samples was optimized and a modified molybdenum blue spectrophotometric method was carried out with excellent precision and selectivity. To di...

Commercially available gold screen-printed electrodes cured at high temperature were modified or functionalized at the surface with gold nanoparticles, mainly produced by a green synthesis method, and other carbon-based nanomaterials in order to enhance the electron transfer between the sulfhydryl groups of the aminothiols cysteine (Cys), methionin...

Molecularly imprinted polymers (MIPs) are synthetic materials used as biomimetic molecular recognition receptors [1]. MIPs are generally obtained by polymerization in presence of a template molecule. Once polymerization is carried out, the template is extracted leaving behind it specific cavities complementary in size, shape and functionality. Due...

The synthesis of a new bulk material based on silicon oxide and poly-(3,4-ethylenedioxythiophene) (PEDOT), the Sonogel-Carbon-PEDOT material, is carried out. The main purpose is to obtain a bare conducting material, aided by statistical experimental design, able to be used as transducer for electrochemical devices. This new material tries also to s...

The application of a novel Poly(3,4-ethylenedioxythiophene)-Tyrosinase/Sonogel-Carbon electrode (PEDOT-Tyr/SNGC) biosensor to beers and wines analysis is proposed. This biosensor implies a new Sinusoidal Current (SC) electrodeposition method to immobilize the enzyme generating a nanostructure surface. The biosensors were characterized electrochemic...

This work consists of developing a simple electroanalytical method which allows the speciation of Cr(VI). Gold modified Carbon Paste Electrodes (CPEs) and unmodified CPEs have been tested for the determination of Cr(VI) in presence of an excess of Cr(III) by using differential pulse voltammetry (DPV), without any accumulation or pre‐concentration t...

In this work, biosensors based on Sonogel-Carbon electrodes modified with poly(3,4-ethylenedioxythiophene) – tyrosinase biocomposite materials have been developed using sinusoidal voltages and currents methods The sinusoidal voltages method uses a sinusoidal voltage signal of a 50 mHz fixed frequency and high amplitude superimposed on a direct curr...

The objective of this work was to ascertain the nature of the components responsible for the reducing and stabilizing properties of Zostera noltii extracts that lead to gold nanoparticle formation using chemical techniques of analysis. In order to achieve this aim, we try the synthesis of AuNPs with three different extracts from plants collected in...

Introduction: Piroxicam (PRX) is a widely consumed anti-inflammatory drug, and the assays of its tablets and gels for quality control are mostly performed through High Performance Liquid Chromatography with Ultraviolet Detector (HPLC-UV). Methods: In this regard, an alternate approach, LaFeO3 nanoparticles-modified carbon paste electrode was prepa...

Calcium sulfate is normally used as a complementary acidifier combined with tartaric acid. The doses corresponding to each one depend on the desired reduction of pH and on the composition of musts. However, considering that there are several interrelated chemical equilibria implied (tartaric acid dissociation, calcium tartrate and potassium bitartr...

In this paper, the sonocatalysis has been successfully used to synthesise silica nanoparticles. The Stöber method which implies silicon alkoxide, ammonia and aqueous alcohol solution with magnetic stirring followed by ultrasound bath was modified with the use of a high-power ultrasound probe. The factors considered to prepare silica nanoparticles w...

Binary metal oxides with different degrees of covalent/ionic character of the oxygen-metal bond are tested as a partial coating of glassy carbon electrode surfaces. The electrocatalytic and antifouling properties of the resulting bicomponent electrode systems are analysed in view of possible applications in different fields of electrochemistry, suc...

Calcium sulphate addition has traditionally been used in Sherry winemaking to reduce the necessary dose of tartaric acid. It is not easy to predict the final pH of a mixed tartaric acid and calcium sulphate addition and to determine the necessary doses to reach the final pH required by the winemaker because there are several interrelated chemical e...

A novel inhibition biosensor used for the detection of sulphides (Na2S) has been developed. The biosensor is based on the immobilisation of horseradish peroxidase (HRP) on the Sonogel-Carbon (SNGC) electrode using glutaraldehyde, Poly(4-vinylpyridine) and gold sononanoparticles (AuSNPs). The Poly(4-vinylpyridine) was used due to its high affinity f...

New amperometric inhibition biosensor for sulfides determination based on HRP and gold sono-nanoparticles immobilized onto sonogel-carbon electrode

A novel inhibition biosensor used for the detection of sulphides (Na2S) has been developed. The biosensor is based on the immobilisation of horseradish peroxidase (HRP) on the Sonogel-Carbon (SNGC) electrode using glutaraldehyde, Poly(4-vinylpyridine) and gold sononanoparticles (AuSNPs). The Poly(4-vinylpyridine) was used due to its high affinity f...

A novel inhibition biosensor used for the detection of sulphides (Na2S) has been developed. The biosensor is based on the immobilisation of horseradish peroxidase (HRP) on the Sonogel-Carbon (SNGC) electrode using glutaraldehyde, Poly(4-vinylpyridine) and gold sononanoparticles (AuSNPs). The Poly(4-vinylpyridine) was used due to its high affinity f...

Acidification of musts is necessary in warm areas where high temperatures during ripening accelerate breathing com- bustion of tartaric acid and, in particular, malic acid in the berries. L(+) tartaric acid, L(-) or D,L malic acid and lactic acids are the only chemical acidifiers authorized by the OIV and European Community regulations. The use of...

SUMMARY. A differential pulse voltammetry (DPV) method for the determination of acetaminophen content in liquid pharmaceutical formulations under developing process is proposed. DP voltammograms were developed in 0.1 M phosphate buffer solution pH = 5.0 at a Sonogel-Carbon electrode (SNGCE), whereas the pulse amplitude was 50 mV, the pulse width 0....

New biosensors based on inhibition for the detection of cyanide and the comparison of the analytical performances of nine enzyme biosensor designs by using three different electrodes: Sonogel-Carbon, glassy carbon and gold electrodes were discussed. Three different horseradish peroxidase immobilization procedures with and without gold sononanoparti...

A rapid in situ biosynthesis of gold nanoparticles (AuNPs) is proposed in which a geranium (Pelargonium zonale) leaf extract was used as a non-toxic reducing and stabilizing agent in a sonocatalysis process based on high-power ultrasound. The synthesis process took only 3.5min in aqueous solution under ambient conditions. The stability of the nanop...

This work describes a comparison of the analytical performances of several horseradish peroxidase gold sono-nanoparticles (AuSNPs) modified electrodes for detecting cyanide (KCN). The sensors were designed by immobilizing horseradish peroxidase (HRP) with and without AuSNPs onto three different types of electrodes: Sonogel-Carbon, glassy carbon and...

The present work reports a study of the electrocatalytic activity of CeO2 nanoparticles and gold sononanoparticles (AuSNPs)/CeO2 nanocomposite, deposited on the surface of a Sonogel-Carbon (SNGC) matrix used as supporting electrode and the application of the sensing devices built with them to the determination of ascorbic acid (AA) used as a benchm...

Graphite powder-based electrodes have the electrochemical performance of quasi-noble metal electrodes with intrinsic advantages related to the possibility of modification to enhance selectivity and their easily renewable surface, with no need for hazardous acids or bases for their cleaning. In contrast with commercial electrodes, for example screen...

The main objective of this study consists of comparing the electrocatalytic activity of different types of gold nanoparticles (AuNPs) obtained from two different synthetic routes (thermal and ultrasonic methods) deposited on the surface of a Sonogel-Carbon (SNGC) matrix and the application of the sensing devices built with them to the determination...

The traditional methods used to evaluate parameters related to beer ageing have been tested, revised and criticised. With this aim, a sampling of lager beers has been carried out. Sulphur dioxide, polyphenols and antioxidant capacity have been determined in fresh and aged beer. Only sulphur dioxide concentration showed relevant differences after th...

The information included in this report supports the contents of the paper "A Flatbed Scanner to Measure Detergency, J. Chem. Educ. 2011, 88, 1314–1317" in order to show the learning context where we apply the technique described in that paper. It also contains instructor notes to help adapt the experiment to local conditions.

The efficiency of a laundry-washing process is typically assessed using reflection measurements. A spectrometer and an integrating sphere are used to obtain the reflection data. The similarities between this equipment and a commercially available flatbed scanner are examined, and the way a flatbed scanner can be used to obtain detergent efficiencie...

An easy, cheap and green synthetic route, using high-power ultrasounds and sodium citrate dihydrate as non-toxic reducing and stabilizer agent, produces gold nanoparticles in aqueous solution, and at ambient conditions. The time required for the synthesis is 5.5 min. The spherical nanoparticles obtained by this route show a homogeneous size distrib...

A new type of sensor based on Sonogel-Carbon materials modified with 1-(2-furoyl)-3-(1-naphthyl)thiourea is presented to be used as an amperometric sensor for metals. Different percentages of modifier were tested in order to optimise the structural and mechanical properties, as well as the electrochemical behaviour.Scanning electron microscopy (SEM...

In this work, a new alternative for the electrochemical determination of catecholamines based on beta-cyclodextrin-Sonogel-Carbon electrodes is reported. The incorporation of beta-CD and graphite in the preparation of the Sonogel-Carbon material leads to a modification of the electrode surface properties which causes a significant increase in the o...

Chemometric methods have been applied to resolve mixture of phenols; phenolic compounds are amongst the most interesting chemical species from an environmental viewpoint. However, the number of papers that apply multivariate calibration methods to resolve electroanalytical signals of mixture of phenols is low.In this paper, we propose a new chemome...

A new chemometric methodology based on the use of peak parameters as direct input data into different multivariate calibration methods is proposed. Different regression techniques such as multilinear regression (MLR), partial least square regression (PLS), principal component regression (PCR) and artificial neural networks (ANN), were utilized in o...

The determination of benzodiazepines in biological fluids is object of great interest for many scientists. In the daily medical practice, it is necessary to perform drug analytical monitorization in order to adequate the dose of these substances to the necessities of the patients, and to avoid toxic effects. In forensic toxicology, benzodiazepines...

In this paper, the influence of carbon particles size on structure and on electrochemical and physical properties of the Sonogel-Carbon electrodes, with respect to Sonogel materials without graphite, have been studied. The materials have been characterized electrochemical and structurally; several Sonogel-Carbon materials were synthesized using dif...

A new electrochemical methodology to determine Cr(VI) in aqueous solutions is presented. The key to this methodology is in the oxidation range. This procedure is based on the electrochemical response of Cr(VI)/1,5- diphenylcarbazide (DPCI) complex as analyzed by differential pulse voltammetry and cyclic voltammetry. This new sensitive, fast and eco...

Successful applications of different analytical procedures to determine quantitatively endosulfan and its metabolites in aqueous media can be found in recent literature. Fundamentally, they have made use of solid-phase extraction (SPE) and gas (GC) or liquid chromatography (LC), sometimes coupled to mass spectrometry (MS). In this paper, a new and...

The electrochemical behavior of a sonogel-carbon electrode towards nine phenolic compounds (chloro-, nitro- and alkyl-phenols) was studied; one of them (4-chloro-3-methylphenol) was used to evaluate characteristics of the electrode, such as accumulation and cleaning procedure of the electrode surface, reproducibility of the measurements, and influe...