Univerzita Pardubice
Stálý URI pro tuto komunituhttps://hdl.handle.net/10195/1
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Článek Omezený přístup peer-reviewedpostprint Biosensor with electrochemically active nanocomposites for signal amplification and simultaneous detection of three ovarian cancer biomarkers(Elsevier Science, 2023) Kovářová, Aneta; Kastrati, Gylxhane; Pekarkova, Jana; Metelka, Radovan; Drbohlavova, Jana; Bílková, Zuzana; Šelešovská, Renáta; Korecká, LucieThe current trend in medical diagnostic methods is to simplify and accelerate diagnosis and bring testing closer to the patient while maintaining the existing analytical criteria. Point-of-care tests (POCT) allow improved screening of population and rapid decisions regarding patient care. In case of cancer, this is a very desirable and valuable factor affecting the survival rate. Biosensors exploiting the bioaffinity interaction of target molecules with specific antibodies, combined with screen-printed electrodes as detection units, meet these criteria perfectly. In this study, we present a new sandwich-type magneto-immunosensor with electrochemical signal generating nanocomposites that was designed for the simultaneous detection and quantification of three biomarkers associated with ovarian cancer, namely human epididymis protein 4 (HE4), alpha-fetoprotein (AFP), and cancer antigen 125 (CA-125). The simultaneous detection was enabled by three different electroactive nanomaterials, namely gold nanoparticles (AuNPs), and CdTe and PbS core-type quantum dots (QDs), which were conjugated with three specific antibodies. Mesoporous silica nanoparticles (SiNPs) were incorporated in nanocomposite for higher loading of electroactive labels, leading to substantial enhancement of electrochemical signal. Square-wave anodic/cathodic stripping voltammetry was used for the detection of metal ions released quantitatively from the captured bioconjugates. Combination of these three elements provided separate non interfering signals, hence enabling simultaneous detection. Using this multiplex immunosensor, up to three biomarkers within the linear concentration ranges of 0.02-20 pM for HE4, 0.45-450 IU L 1 for CA-125, and 0.1-500 ng L 1 for AFP could be detected and quantified. The analytical parameters obtained fit the requirements of early-stage disease detection.Článek Omezený přístup peer-reviewedpostprint Effect of different modification by gold nanoparticles on the electrochemical performance of screen‑printed sensors with boron‑doped diamond electrode(2023) Matvieiev, Oleksandr; Šelešovská, Renáta; Marton, Marián; Hatala, Michal; Metelka, Radovan; Weis, Martin; Vojs, MarianScreen-printed sensors with chemically deposited boron-doped diamond electrodes (BDDE) were modifed with diferent types of gold nanoparticles (AuNPs) according to a new original procedure. Physically and electrochemically deposited AuNPs had various sizes and also nanoporous character. They also difer in shape and density of surface coverage. The developed sensors were characterized using scanning electron microscopy and Raman spectroscopy. Their electrochemical properties were studied using cyclic voltammetry and electrochemical impedance spectrometry of selected outer sphere ([Ru(NH3)6]Cl3) and inner sphere (K3[Fe(CN)6], dopamine) redox markers. The application possibilities of such novel screen-printed sensors with BDDE modifed by AuNPs were verifed in the analysis of the neurotransmitter dopamine. The best analytical performance was achieved using printed sensors modifed with the smallest AuNPs. The achieved limit of detection values in nanomolar concentrations (2.5 nmol L−1) are much lower than those of unmodifed electrodes, which confrms the signifcant catalytic efects of gold nanoparticles on the surface of the working electrode. Sensors with the best electrochemical properties were successfully applied in the analysis of a model solution and spiked urine samples.Článek Omezený přístup peer-reviewedpostprint Voltammetric analysis of mephenoxalone drug in pharmaceutical and biological samples using novel screen-printed sensor with boron-doped diamond electrode(2023) Matvieiev, Oleksandr; Šelešovská, Renáta; Sokolová, Romana; Jerga, Radek; Skopalová, Jana; Barták, Petr; Chýlková, Jaromíra; Vojs, MarianA novel screen-printed sensor (SPE) with boron-doped diamond electrode (BDDE) for determination of a muscle relaxant and mild anxiolytic mephenoxalone (MNL) was developed. The sensor utilizes the electrochemical oxidation of MNL, which was firstly studied in aqueous solution using oxygen terminated BDDE. MNL provided an irreversible anodic signal at a potential of + 1380 mV (vs. Ag/AgCl/KCl sat.) over a wide pH range. BrittonRobinson buffer (pH 9) was selected as a suitable electrolyte and the square-wave voltammetric method (SWV) was developed. The low detection limit (55 nmol L–1), wide linear dynamic range (0.1–30 µmol L− 1), and good recovery in the analysis of model and pharmaceutical samples (RSD < 1.77%) were attained. Subsequently, the new method was successfully transferred to SPE, which can find application in point-of-care testing. These sensors proved excellent sensitivity and reproducibility in the analysis of biological samples (RSD < 4.94%) without pretreatment and no need of electrolyte. Based on gas chromatography with mass spectrometry (GC-MS) analysis of preparative electrolysis products, a mechanism of the electrochemical oxidation of MNL was proposed, describing the oxidative cleavage of the alkoxybenzene ring. These results were supported with HOMO spatial distribution calculations and atomic charges calculations for arising radical cations, and with spectroelectrochemical measurements.Článek Omezený přístup peer-reviewedpostprint Recent advances in the use of screen-printed electrodes in drug analysis: A review(Elsevier Science BV, 2023) Kelíšková, Pavlína; Matvieiev, Oleksandr; Janíková, Lenka; Šelešovská, RenátaThis review discusses the recent significant advancements over the past three years (i.e., 2021-2023) in the application of screen-printed electrodes (SPE) in drug analysis. SPE gained considerable interest due to their simplicity, affordability, and versatility. The review covers unmodified and modified SPE and highlights their potential in determining of pharmaceuti-cals, including narcotics, psychotropic agents, antidiabetic medications, anti-inflammatory drugs, antibiotics, and chemo-therapeutics. Unmodified SPE provide rapid drug screening and detection, aid in forensic analysis, and contribute to the fight against drug proliferation. SPE modified with various nanomaterials, polymers, composites, and biomolecules enhance the sensitivity and selectivity of the electrodes, enabling precise analysis of drugs in samples with a complex matrix. The review summarizes the achievements of SPE for medical or forensic purposes and quality control of pharma-ceutical products.Článek Omezený přístup peer-reviewedpostprint Recent advances in modified boron-doped diamond electrodes: A review(Elsevier Science, 2023) Hrdlicka, Vojtech; Matvieiev, Oleksandr; Navratil, Tomas; Šelešovská, RenátaThis review presents recent developments in the modification of boron-doped diamond electrodes (BDDEs) and their application in biosensing, electroanalysis, electrosynthesis, fuel cell construction, and CO2 reduction. The various modification procedures are also described. In addition to the outstanding properties of unmodified BDDEs, they have recently become a highly functional substrate for various modifications. The modifications of BDDEs by metals or metal oxides were aimed at increasing the surface area and promoting electron transfer kinetics or electrocatalytic activity for CO2 reduction, sensing of oxygen, or stripping voltammetry. Modification by polymers such as Nafion, polypyrrole, or polyaniline was used mostly to fine-tune the specificity of voltammetric analyses and interference suppression. DNA, enzymes, or other biomolecules were used to obtain specific sensing capabilities. These chemical modifications are critically compared to the other strategies used for BDDEs, including varied boron doping levels, the ratio of sp2 to sp3 carbon, and BDDE surface pre-treatment.Článek Omezený přístup peer-reviewedpostprint A new voltammetric approach for the determination of the growth retardant paclobutrazol in the presence of difenoconazole in pesticide preparations(Elsevier Science SA, 2023) Jiroutová, Alona; Chýlková, Jaromíra; Váňa, Jiří; Matvieiev, Oleksandr; Janíková, Lenka; Šelešovská, RenátaPaclobutrazol (PBZ) belongs to the group of triazole pesticides, which act as inhibitors of the synthesis of phy-tohormones and thereby regulate plant growth. In this study, the electrochemical oxidation of this pesticide was investigated for the first time. PBZ provides on a boron-doped diamond electrode (BDDE) one irreversible anodic peak over a wide pH range of the supporting electrolyte at a significantly positive potential of ca. +1950 mV (vs Ag/AgCl), which is suitable for electroanalytical purposes. Based on the LC-MS analysis of the products of electrolysis, the mechanism of the electrochemical oxidation of PBZ was also proposed. The method developed for the determination of PBZ using differential pulse voltammetry in connection with BDDE in the supporting electrolyte of 0.07 mol L-1 NaOH with 33 % of acetonitrile provided a very low limit of quantification amounted to 2.6 x 10-7 mol L-1. Under optimized conditions, the determination of the stud-ied plant growth regulator is also possible in the presence of the other insecticide difenoconazole, which is usu-ally found in commercial preparations mixed with PBZ. For natural water samples with very low concentrations of pesticides, a method of analyte pre-concentration using strong acid Amberlite (R) IRC120 H catex was developed. The proposed procedures were successfully applied for the analysis of model solutions, commercially available pesticide preparations, and spiked natural waters.Článek Omezený přístup peer-reviewedpostprint Electrochemical behavior of fungicide tebuconazole and its voltammetric determination on an oxygen-terminated boron-doped diamond electrode(Elsevier Science SA, 2023) Šelešovská, Renáta; Sokolova, Romana; Krejčová, Kateřina; Schwarzova-Peckova, Karolina; Mikysek, Tomáš; Matvieiev, OleksandrThe first study on electrochemical oxidation of triazole fungicide tebuconazole was performed using an oxygen-terminated boron-doped diamond electrode. The irreversible anodic process occurring at + 1.75 V (vs Ag/AgCl/KCl(sat.)) in 0.1 mol/L HNO3 was studied by cyclic voltammetry, IR spectroelectrochemistry, and density functional theory calculations. The oxidation of tebuconazole leads to the formation of the hydroxylated and dihydroxylated derivatives on the 4-chlorophenyl moiety. Also, the corresponding o-quinone derivative was detected. Further, the anodic signal was used to develop a differential pulse voltammetric method for tebuconazole determination with the following parameters: linear dynamic range from 5.0 x 10-7 to 8.3 x 10-5 mol/L and limit of detection of 1.5 x 10-7 mol/L. The method was successfully applied to the analysis of a commercially available pesticide formulation and model samples of river water after preconcentration of tebuconazole using Amberlite (R) IRC120 H ion-exchange resin in H+ cycle.Konferenční objekt Omezený přístup peer-reviewedpostprint A Sensitive Voltammetric Approach Employing a Bare Boron-Doped Diamond Electrode as a Sensor for the Determination of Hydroxocobalamin(MDPI AG (Multidisciplinary Digital Publishing Institute), 2023) Janíková, Lenka; Šelešovská, Renáta; Stýblová, Iveta; Chýlková, JaromíraThe voltammetric behavior of hydroxocobalamin (OH-CBL) was firstly studied by employing a bare boron-doped diamond electrode as a working electrode. It was found that OH-CBL provided four anodic signals on BDDE in acidic supporting electrolytes and one cathodic signal. The anodic peak situated at +412 mV (vs. Ag|AgCl|KCl (sat.) recorded in 0.1 mol/L H2SO4) was found to be suitable for analytical purposes due to its position and shape. A novel voltammetric approach based on differential pulse voltammetry was developed and it was found as a sensitive analytical tool, with low limit of detection (LD = 13.2 nmol/L), applicable in analysis of vitamin preparations.Konferenční objekt Otevřený přístup peer-reviewedpostprint (accepted version) Voltammetric Determination of Daminozide in Plant Material(BEST Servis, 2022) Chýlková, Jaromíra; Usenko, Alona; Sedlák, Miloš; Bartáček, Jan; Cuhorka, Jiří; Šelešovská, Renáta; Navrátil, Tomáš; Fojta, Miroslav; Schwarzová, KarolinaA new procedure for the determination of daminozide in plant material was proposed. The plant sample is dried in a vacuum oven at 50°C and 9 mbar pressure to constant weight. 96 % ethanol is used to isolate the analyte from the organic matrix under ultrasonication for 2 minutes. This is followed by filtration of the resulting suspension and isolation of the daminozide from the filtrate using Amberlite® IRC120 H catex in an H+ cycle. The analyte is displaced from the ion-exchange with a weakly alkaline NaCl solution at a concentration of 1 mol L1. The voltammetric analysis of daminozide is performed by anodic oxidation in 0.1 mol L1 chloroacetate buffer of pH 3.2 using a boron-doped diamond electrode.Konferenční objekt Otevřený přístup peer-reviewedpostprint (accepted version) Electrochemical Techniques in Monitoring of Nervous System Drugs(BEST Servis, 2022) Choinska, Marta; Hrdlička, Vojtěch; Skopalová, Jana; Šelešovská, Renáta; Kolivoška, Viliam; Navrátil, Tomáš; Navrátil, Tomáš; Fojta, Miroslav; Schwarzová, KarolinaDrugs of the nervous system (ATC group N) belong generally to the most commonly (mis)used substances worldwide. Their determination and monitoring of these drugs and their metabolites in various body fluids or environmental matrices represent a challenge for analytical chemists. Our research is focused on the application of electrochemical methods in the monitoring of the most frequently prescribed and the newly introduced nervous system drugs of precisely specified structures and/or of defined properties. For toxicological and pharmacokinetic reasons, emphasis has been placed on investigating the reaction mechanisms of their metabolite formation. New or alternative to commonly used electroanalytical methods applicable for monitoring and characterization of target compounds in their pure state, in body fluids, wastewaters, and other environmental matrices, has been developed. To improve the chemometric parameters and sensing characteristics, attention was be paid to the construction of new electrochemical sensors, detectors (e.g. screen-printed, 3D printed), or cells, based on (modified/unmodified) traditional or nontraditional materials, preferably usable at the point-of-care.