Photoelectrochemical determination of phloroglucinol based on a combination of a ceramic perovskite and bismuth vanadate.

Phloroglucinol (PL) or 1,3,5-trihydroxybenzene is a phenolic compound used therapeutically for its antispasmodic properties. However, an overdose or prolonged exposure to PL can have harmful effects on human health. This work describes for the first time the development of a photoelectrochemical (PEC) sensor to determine PL.

Membraneless, self-powered immunosensing of a cardiac biomarker by exploiting a PEC platform based on CaBiTaO combined with bismuth oxyiodides.

This work describes the development of a membraneless, self-powered immunosensor exploiting a photoelectrochemical system based on two photoelectrodes for cardiac troponin I (cTn). An electrode based on CaBiTaO combined with bismuth oxyiodides (BiOI/BiOI/BiOI) was modified with the cTnI antibody (-cTnI) and applied in a photoelectrochemical cell as a photoanode. To perform the cTnI detection exploiting a self-powered photoelectrochemical setup, the immunosensor (-cTnI/BiOI/BiOI/BiOI/CaBiTaO/FTO) was coupled to a photoelectrochemical cell containing a photocathode based on CuBiO (CBO/FTO) for zero-biased photoelectrochemical immunosensing of cardiac troponin I (cTnI) biomarker.

Photoelectrochemical Determination of Cardiac Troponin I as a Biomarker of Myocardial Infarction Using a BiS Film Electrodeposited on a BiVO-Coated Fluorine-Doped Tin Oxide Electrode.

A sensitive and selective label-free photoelectrochemical (PEC) immunosensor was designed for the detection of cardiac troponin I (cTnI). The platform was based on a fluorine-doped tin oxide (FTO)-coated glass photoelectrode modified with bismuth vanadate (BiVO) and sensitized by an electrodeposited bismuth sulfide (BiS) film. The PEC response of the BiS/BiVO/FTO platform for the ascorbic acid (AA) donor molecule was approximately 1.

A low-cost carbon-based electrochemical platform for determining 2,3-dihydroxyphenol: applications in natural water and biodiesel samples.

2,3-Dihydroxyphenol (DHP) is a phenolic compound that has been used as an additive in biodiesel to avoid the auto-oxidation of biofuels and also in the production of cosmetic products. However, this substance can be released into the environment during its manufacture, transport, disposal and industrial use and can be harmful to health due to its toxicity, and hence, monitoring its presence in different samples is very important. Therefore, this work describes an electroanalytical study of DHP using different carbon-based pastes prepared to evaluate which one would be more promising to be used as an electrochemical platform for DHP quantification.

Zero-Biased Photoelectrochemical Detection of Cardiac Biomarker Myoglobin Based on CdSeS/ZnS Quantum Dots and Barium Titanate Perovskite.

Cardiovascular diseases are considered one of the leading causes of premature mortality of patients worldwide. Therefore, rapid diagnosis of these diseases is crucial to ensure the patient's survival. During a heart attack or severe muscle damage, myoglobin is rapidly released in the body to constitute itself as a precise biomarker of acute myocardial infarction.

Evaluation of a photoelectrochemical platform based on strontium titanate, sulfur doped carbon nitride and palladium nanoparticles for detection of SARS-CoV-2 spike glycoprotein S1.

This work aims to develop a photoelectrochemical (PEC) platform for detection of SARS-CoV-2 spike glyprotein S1. The PEC platform is based on the modification of a fluorine-doped tin oxide (FTO) coated glass slide with strontium titanate (SrTiO or ST), sulfur-doped carbon nitride (g-CN-S or CNS) and palladium nanoparticles entrapped in aluminum hydroxide matrix (PdAlO(OH) or PdNPs). The PEC platform was denoted as PdNPs/CNS/ST/FTO and it was characterized by SEM, TEM, FTIR, DRX, and EIS.

Immunodiagnostic of leprosy exploiting a photoelectrochemical platform based on a recombinant peptide mimetic of a Mycobacterium leprae antigen.

The first serum diagnosis of leprosy based on the detection of antibodies of patients using a recombinant mimetic peptide (PGL1M3R) as recognition element and exploiting a photoelectrochemical sensor is presented in this work. The photoeletrochemical platform consists of cadmium sulphide and nickel hydroxide electrodeposited on fluorine-doped tin oxide coated glass slide (CdS/Ni(OH)/FTO). The optical band gap and flat band potential of the photoelectroactive materials were evaluated by UV-Vis spectroscopy and electrochemical impedance spectroscopy.

Correction to: Photoelectrochemical sensing of tannic acid based on the use of TiO sensitized with 5-methylphenazinium methosulfate and carboxy-functionalized CdTe quantum dots.

The published version of this article, unfortunately, contains an error in that Fig. 2 shows the same study as Fig. 3.

Photoelectrochemical sensing of tannic acid based on the use of TiO sensitized with 5-methylphenazinium methosulfate and carboxy-functionalized CdTe quantum dots.

The article describes a method for determination of tannic acid in extracts of medicinal plants. Tannic acid (TA) is an antioxidant and has anticancer and antimicrobial properties. Titanium dioxide nanoparticles (TiO) were co-sensitized with 5-methylphenazinium methosulfate (PMS) and carboxy-functionalized cadmium telluride quantum dots (CdTe QDs), and immobilized on a fluorine-doped tin oxide electrode.

Ultrasensitive Determination of Malathion Using Acetylcholinesterase Immobilized on Chitosan-Functionalized Magnetic Iron Nanoparticles.

A renewable, disposable, low cost, and sensitive sensor for the detection of organophosphorus pesticides was constructed by immobilizing the acetylcholinesterase enzyme (AChE), via glutaraldehyde, on magnetic iron nanoparticles (Fe₃O₄) previously synthesized and functionalized with chitosan (CS). The sensor was denoted AChE/CS/Fe₃O₄. The magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy.

Photoelectrochemical determination of tert-butylhydroquinone in edible oil samples employing CdSe/ZnS quantum dots and LiTCNE.

A novel photoelectrochemical sensor was developed for determination of tert-butyl-hydroquinone (TBHQ) in edible vegetable oils, based on CdSe/ZnS core-shell quantum dots sensitized with lithium tetracyanoethylenide (LiTCNE). The CdSe/ZnS/LiTCNE photoelectrochemical sensor presented a TBHQ photocurrent about 13-fold higher and a charge transfer resistance 62-fold lower than observed for a CdSe/ZnS sensor. The photoelectrochemical sensor showed selectivity to TBHQ, with a high photocurrent for this antioxidant compared to the photocurrent responses for other phenolic antioxidants.

Applicability of a novel immunoassay based on surface plasmon resonance for the diagnosis of Chagas disease.

Background: We defined the methodological criteria for the interpretation of the results provided by a novel immunoassay based on surface plasmon resonance (SPR) to detect antibodies anti-Trypanosoma cruzi in human sera (SPRCruzi). Then, we evaluated its applicability as a diagnostic tool for Chagas disease.

Methods: To define the cut-off point and serum dilution factor, 57 samples were analyzed at SPRCruzi and the obtained values of SPR angle displacement (ΔθSPR) were submitted to statistical analysis.

SPR analysis of the interaction between a recombinant protein of unknown function in Leishmania infantum immobilised on dendrimers and antibodies of the visceral leishmaniasis: A potential use in immunodiagnosis.

In this work, an SPR immunosensor was developed to elucidate the reaction kinetics between a protein of unknown function in Leishmania infantum (hypothetical C1 protein) and specific antibodies of the visceral leishmaniasis (VL). A platform, which is based on layer-by-layer assembly was formed by cysteamine in combination with a fourth-generation poly(amidoamine) dendrimer (PAMAM(G4)) on gold surface for the immobilisation of the protein. This film resulted in amplification of the signal of SPR.

Ultrasensitive biosensor for detection of organophosphorus pesticides based on a macrocycle complex/carbon nanotubes composite and 1-methyl-3-octylimidazolium tetrafluoroborate as binder compound.

This work describes the highly sensitive detection of organophosphorus pesticides employing the cobalt(II) 4,4,4,4-tetrasulfo-phthalocyanine (CoTSPc) macrocycle complex, carbon nanotubes (CNT), and 1-methyl-3-octylimidazolium tetrafluoroborate (OMIM[BF4]). The technique is based on enzyme acetylcholinesterase (AChE) inhibition. The composite was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and amperometry.

Development of a label-free immunosensor based on surface plasmon resonance technique for the detection of anti-Leishmania infantum antibodies in canine serum.

In this work, a surface plasmon resonance (SPR) immunosensor was developed using an 11-mercaptoundecanoic acid (11-MUA) modified gold SPR sensor chip for the detection of anti-Leishmania infantum antibodies. The soluble antigens of L. infantum were securely immobilized on an SPR gold disk by an 11-MUA self-assembled monolayer.

Development of a sensor for L-Dopa based on Co(DMG)(2)ClPy/multi-walled carbon nanotubes composite immobilized on basal plane pyrolytic graphite electrode.

L-Dopa is the immediate precursor of the neurotransmitter dopamine, being the most widely prescribed drug in the treatment of Parkinson's disease. A sensitive and selective method is presented for the voltammetric determination of L-Dopa in pharmaceutical formulations using a basal plane pyrolytic graphite (BPPG) electrode modified with chloro(pyridine)bis(dimethylglyoximato)cobalt(III) (Co(DMG)(2)ClPy) absorbed in a multi-walled carbon nanotube (MWCNT). Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy were used to characterize the materials.

Dissolved oxygen amperometric sensor based on layer-by-layer assembly using host-guest supramolecular interactions.

The development of a simple, efficient and sensitive sensor for dissolved oxygen is proposed using the host-guest binding of a supramolecular complex at a host surface by combining a self-assembled monolayer (SAM) of mono-(6-deoxy-6-mercapto)-beta-cyclodextrin (betaCDSH), iron (III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeTMPyP) and cyclodextrin-functionalized gold nanoparticles (CDAuNP). The supramolecular modified electrode showed excellent catalytic activity for oxygen reduction. The reduction potential of oxygen was shifted about 200 mV toward less negative values with this modified electrode, presenting a peak current much higher than those observed on a bare gold electrode.

Amperometric sensor for nitrite using a glassy carbon electrode modified with alternating layers of iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin and cobalt(II) tetrasulfonated phthalocyanine.

The development of a highly sensitive amperometric sensor for nitrite using a glassy carbon electrode modified with alternated layers of iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeT4MPyP) and cobalt(II) tetrasulfonated phthalocyanine (CoTSPc) is described. The modified electrode showed an excellent catalytic activity and stability for the nitrite oxidation decreasing the peak potentials about 200mV toward less positive values and presenting much higher peak currents than those obtained on the bare GC electrode. A linear response range of 0.

Voltammetric determination of 4-nitrophenol at a lithium tetracyanoethylenide (LiTCNE) modified glassy carbon electrode.

The reduction of 4-nitrophenol (4-NP) has been carried out on a modified glassy carbon electrode using cyclic and differential pulse voltammetry (DPV). The sensor was prepared by modifying the electrode with lithium tetracyanoethylenide (LiTCNE) and poly-l-lysine (PLL) film. With this modified electrode 4-NP was reduced at -0.

Electrocatalysis of reduced L-glutathione oxidation by iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeT4MPyP) adsorbed on multi-walled carbon nanotubes.

The development of a highly sensitive voltammetric sensor for reduced l-glutathione (GSH) using a basal plane pyrolytic graphite (BPPG) electrode modified with iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeT4MPyP) adsorbed on multi-walled carbon nanotubes (MWCNT) is described. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to verify the morphologies and composition of the MWCNT after modification with the FeT4MPyP complex. The modified electrode showed very efficient electrocatalytic activity for l-glutathione oxidation, substantially decreasing the oxidation peak to -0.

Amperometric sensor for nitrite based on copper tetrasulphonated phthalocyanine immobilized with poly-L-lysine film.

In this work, an amperometric sensor for nitrite detection based on a glassy carbon electrode modified with copper tetrasulphonated phthalocyanine immobilized by polycationic poly-L-lysine film is presented. The modified electrode showed an excellent catalytic activity toward nitrite oxidation. A linear response range from 0.

A highly sensitive amperometric sensor for oxygen based on iron(II) tetrasulfonated phthalocyanine and iron(III) tetra-(N-methyl-pyridyl)-porphyrin multilayers.

The development of a highly sensitive sensor for oxygen is proposed using a glassy carbon (GC) electrode modified with alternated layers of iron(II) tetrasulfonated phthalocyanine (FeTsPc) and iron(III) tetra-(N-methyl-pyridyl)-porphyrin (FeT4MPyP). The modified electrode showed excellent catalytic activity for the oxygen reduction. The reduction potential of the oxygen was shifted about 330 mV toward less negative values with this modified electrode, presenting a peak current much higher than those observed on a bare GC electrode.

Electrocatalytic determination of reduced glutathione in human erythrocytes.

The determination of reduced glutathione (GSH) in human erythrocytes using a simple, fast and sensitive method employing a glassy carbon electrode modified with cobalt tetrasulfonated phthalocyanine (CoTSPc) immobilized in poly(L: -lysine) (PLL) film was investigated. This modified electrode showed very efficient electrocatalytic activity for anodic oxidation of GSH, decreasing substantially the anodic overpotentials for 0.2 V versus Ag/AgCl.

Cobalt tetrasulphonated phthalocyanine immobilized on poly-L-lysine film onto glassy carbon electrode as amperometric sensor for cysteine.

The present work describes the development of a simple and efficient method for the amperometric determination of cysteine (CySH) in wild medium at an applied potential of 0.150 V versus Ag/AgCl. In this sense, the electrocatalytic oxidation of cysteine (CySH) was carried out on a glassy carbon electrode modified with cobalt tetrasulphonated phthalocyanine (CoTSPc) and poly-L-lysine (PLL) film.