Papers by Aleksander Ciszewski
Microchimica Acta, 2016
An efficient and rapid method was developed for the preparation of halloysite nanotubes (HNTs) lo... more An efficient and rapid method was developed for the preparation of halloysite nanotubes (HNTs) loaded with Pd nanoparticles (PdNPs) to make a non-enzymatic sensor for glucose. In the preparation step, HNTs self-assembled by sodium dodecylsulfate (SDS) provide an ideal template for loading and arrangement of PdNPs on HNTs. The obtained PdNPs-HNTs nanocomposite material was placed on a glassy carbon electrode to detect glucose. The morphology and composition of the PdNPs-HNTs was investigated by using X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectrum (EDX). Electrochemical impedance spectroscopy (EIS) reveals charge transfer resistance for the modified electrode. Cyclic voltammetry and amperometry were used to measure the electrocatalytic activity of the PdNP-HNT-modified electrode for non-enzymatic oxidation of glucose. The current response of the PdNP-HNT-modified electrode towards glucose covers two linear regions (0.5 μM to 2.0 mM and 2.0 mM to 15.0 mM). The detection limit is 0.43 μM. The present study indicated that the combination of PdNPs and HNTs endows the sensor with excellent electrocatalytic activity, selectivity, good storage stability and sensitivity.
The Analyst, 1992
... 7, pp. 382-389. Vergara. T., Marin, D., and Vera, J.. Anal. Chim. ... 16 Hart, JP, Electroana... more ... 7, pp. 382-389. Vergara. T., Marin, D., and Vera, J.. Anal. Chim. ... 16 Hart, JP, Electroanalysis of Biologically Important Com-pounds, Ellis Horwood, Chichester, 1990, ch. 4, p. 164. 17 Ciszewski, A., Studnickova, M., and Fischer, O . , Bioelectro-chem. Bioenerg., 1984. 13.25. 18 ...
Journal of Cardiovascular Pharmacology, 2012
Most patients with diabetes also have hypertension, a risk factor associated with atherothromboti... more Most patients with diabetes also have hypertension, a risk factor associated with atherothrombotic disease and characterized by endothelial cell (EC) dysfunction and loss of nitric oxide (NO) bioavailability. Recent studies suggest a possible antihypertensive effect with dipeptidyl peptidase-4 (DPP4) inhibition; however, the underlying mechanism is not understood. In this study, we tested the effects of the DPP4 inhibitor, saxagliptin, on EC function, blood pressure, and soluble intercellular adhesion molecule 1 (sICAM-1) levels in hypertensive rats. Spontaneously hypertensive rats were treated with vehicle or saxagliptin (10 mg$kg 21 $day 21) for 8 weeks. NO and peroxynitrite (ONOO 2) release from aortic and glomerular ECs was stimulated with calcium ionophore and measured using electrochemical nanosensor technology. Changes in EC function were correlated with fasting glucose levels. Saxagliptin treatment was observed to increase aortic and glomerular NO release by 22% (P , 0.001) and 23% (P , 0.001), respectively, with comparable reductions in ONOO 2 levels; the NO/ONOO 2 ratio increased by .50% in both EC types (P , 0.001) as compared with vehicle. Saxagliptin also reduced mean arterial pressure from 170 6 10 to 158 6 10 mm Hg (P , 0.001) and decreased sICAM-1 levels by 37% (P , 0.01). The results of this study suggest that DPP4 inhibition reduces blood pressure and inflammation in hypertensive rats while increasing NO bioavailability.
Electrochimica Acta, 2009
Activated carbon fiber cloths (AC) and hydrophobic microporous polypropylene (PP) membrane, both ... more Activated carbon fiber cloths (AC) and hydrophobic microporous polypropylene (PP) membrane, both modified by acetone aldol condensation products, and filled with polymer hydrogel were used as electrodes, separator and electrolyte in electric double layer capacitors (EDLCs). Polymer hydrogel used was based on poly(acrylamide) (PAAM), KOH and water. Electrochemical characteristics of EDLCs were investigated by cyclic voltammetry and galvanostatic charge-discharge cycle tests and also by impedance spectroscopy, compared with a case of the capacitor with only a KOH aqueous solution used as an electrolyte. As a result, the capacitor with polymer hydrogel was found to exhibit higher capacitance than that with the KOH aqueous solution and an excellent high-rate dischargeability. The above results provide valuable information to explore novel composition of EDLCs.
Electroanalysis, 1995
This work focuses on the electrochernical synthesis and characterization of a conductive polymeri... more This work focuses on the electrochernical synthesis and characterization of a conductive polymeric nickel-curcumin film and its application for electrocatalytic oxidation of methanol in alkaline solutions. It has been found that a glassy carbon electrode modified by this film acts as a very effective catalyst for oxidation of alcohols. Electropolymerization of the nickel-curcumin complex and oxidation of methanol have been studied by cyclic voltammetry. The described modified electrode provides a durable catalytic surface which allows the voltammetric oxidation of methanol: in 0.1 M NaOH electrolyte the resulting anodic peak is at 0.59 V (vs. SCE). Electrooxidation was not possible at bare glassy carbon electrodes, at least before the onset of the electrolyte decomposition. The mechanism of modifying the film formation has been discussed.
Analytical Chemistry, 1989
Experimental .data obtained by dlfferentlal pulse anodlc strlpplng voltammetry and electrothermal... more Experimental .data obtained by dlfferentlal pulse anodlc strlpplng voltammetry and electrothermal vllporization Inductlvely coupled plasma atomic emlsslon spectroscopy determlnatlons of amounts of copper and lead deporlted on glassy carbon electrodes ersentlally valldate a recently published model for the process of preconcentratlon of metal Ions by electrodepooltion. Data elucidating the related phenomena of Bmoctnt d8podt* equmrhm concenkatbn of U n r~V e r e d Ions, and percent recovery have been determlned and are discussed. For solution concentrations that allow mrinHayer electrock c?versge (usually greater than lo-' M), ec@brh concentrations of cations remalnlng In solullon are ladependent d Inttlal concentratlons. For concentratknsfdevant to trace metal analyols, less than lo-' M, and monolayer or less electrode ooverage, data show Inltlakoncentratlon-dependent liinlts to electrochemlcal preconcentratlon, which decrease percent recovery. Electrodepodtion parameters that mlnhnlre equlllbrlum concentration levels are dlocussed. The analytical Importance of the verlfled model b that, for a set of experlmental condltlons, It allows calculation of predlcted recoverbs from data collected at macrocorlcentratbn levels to concentratlm levels 3 magnltudes lower.
Analytica Chimica Acta, 1983
ABSTRACT
Electrochimica Acta, 2012
The organometallic complex of nickel (S)-[O-[(N-benzylpropyl)amino](phenyl)methyleneiminoacetate(... more The organometallic complex of nickel (S)-[O-[(N-benzylpropyl)amino](phenyl)methyleneiminoacetate(2-)-N,N ,N-nickel(II), labeled Ni-(S)BPB-Gly, irreversibly adsorbed on a glassy carbon electrode, displays electrocatalytic activity toward the oxidation of methanol in alkaline solution. Electrochemical properties of the resulting material deposited as a redox film have been investigated by cyclic voltammetry. Using Laviron's theory, the electron-transfer rate constant and the transfer coefficient were determined to be k = 1.94 s −1 and ˛ = 0.5, respectively, for a poly-Ni-(S)BPB-Gly film (Ni = 9 × 10 −10 mol cm −2) on a glassy carbon electrode in 0.1 M sodium hydroxide solution. Chronoamperometric studies were also used to determine the catalytic rate constant for the catalytic reaction of the tested modifier with methanol (k cat = 0.33 × 10 5 cm 3 mol −1 s −1). The dependence of the methanol oxidation current on the alcohol concentration and on the number of redox centers Ni(II)/Ni(III) is discussed. From the fact that the oxidation current increases with an increase of film thickness it is evident that the electrocatalytic reaction occurs inside the tested film. The system examined is a typical example of a redox layer with 3D properties. The modified electrode for methanol oxidation is characterized by simple preparation, good stability and good reproducibility.
Journal of Power Sources, 2010
Activated carbon (AC) fiber cloths and a hydrophobic microporous polypropylene (PP) membrane, bot... more Activated carbon (AC) fiber cloths and a hydrophobic microporous polypropylene (PP) membrane, both modified with lithiated acetone oligomers, were used as electrodes and a separator in electric double layer capacitors (EDLCs) with aqueous lithium hydroxide (LiOH) as the electrolyte. Electrochemical characteristics of EDLCs were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge cycle tests and impedance spectroscopy (EIS), compared with a case of the capacitor with aqueous potassium hydroxide (KOH) as an electrolyte. As a result, the capacitor with LiOH aqueous solution and a modified separator and electrodes was found to exhibit higher specific capacitance, maximum energy stored and maximum power than that with KOH aqueous solution.
Electrochimica Acta, 2013
We demonstrate, for the first time, the chemical/electrochemical synthesis of uniformly dispersed... more We demonstrate, for the first time, the chemical/electrochemical synthesis of uniformly dispersed nickel hydroxide nanoparticles (NPs) embedded in a chitosan (CS) membrane deposited onto a glassy carbon (GC) electrode. The morphology of this composite was investigated by scanning electron microscopy (SEM). The SEM results show that NPs have nano-globular structure in the range 10-100 nm. This composite displays electrocatalytic activity toward oxidation of glucose in alkaline solution. The electrochemical properties of the resulting material deposited as a redox film have been investigated by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. Using Lavirin's theory, the electron-transfer rate constant and the transfer coefficient were determined to be k s = 4.1 s −1 and ˛ = 0.42, respectively, for a modifier film (Ni = 7.1 × 10 −10 mol cm −2) on a GC electrode in 0.1 M sodium hydroxide solution. The modified electrode for glucose oxidation is characterized by simple preparation, good stability, good reproducibility, and data from the amperometric current time curves recorded by holding the potential of the modified electrode at 0.75 V for 60 s for different glucose concentrations show a sensitivity of 72 A mM −1 cm −2 .
International journal of electrochemical science
We demonstrate, for the first time, the chemical/electrochemical synthesis of uniformly dispersed... more We demonstrate, for the first time, the chemical/electrochemical synthesis of uniformly dispersed nickel hydroxide nanoparticles (NPs) embedded in a chitosan (CH) membrane deposited on a glassy carbon (GC) electrode. The morphology of this composite was investigated by scanning electron microscopy (SEM). The SEM results show that NPs have a nano-globular structure in the range 10 ÷ 100 nm. This composite displays electrocatalytic activity toward oxidation of methanol in alkaline solution. The electrochemical properties of the resulting material deposited as a redox film have been investigated by cyclic voltammetry and chronoamperometric techniques. Using Lavirin's theory the electron-transfer rate constant and the transfer coefficient were determined to be k s = 4.1 s-1 and α = 0.42, respectively, for a modifier film (Γ Ni = 7.1 x 10-10 mol cm-2) on a GC electrode in 0.1 M sodium hydroxide solution. Chronoamperometric studies were also used to determine the catalytic rate constant for the catalytic reaction of the tested modifier with methanol (k ch = 1.7 x 10 4 cm 3 mol-1 s-1). The dependence of the methanol oxidation current on alcohol concentration is discussed. The modified electrode for methanol oxidation is characterized by simple preparation, good stability and good reproducibility.
Talanta, 1988
The possibilities for eliminating the matrix effect caused by large concentrations of titanium in... more The possibilities for eliminating the matrix effect caused by large concentrations of titanium in an EDTA-based electrolyte have been examined. In these solutions titanium gives a DPASV peak, the height of which decreases with increase in preconcentration time. This effect depends on the pH and is probably caused by impurities in the EDTA. Complete damping of the titanium peak by means of this effect is not possible. The influence of the following surfactants on the DPASV peak for titanium in 0.2M EDTA at pH 4.5 was investigated: polyoxyethylated alkylphenols having an average of 3 and 9.5 ethylene oxide sub-units; polyoxyethylene alcohols having an average of 5 and 20 ethylene oxide sub-units; polyoxyethylene (glycerol mono-oleate) ether having an average of 20 ethylene oxide sub-units; polyoxyethylene (sorbitol mono-oleate) ether having an average of 20 ethylene oxide sub-units; poly(ethylene oxide) having M.W. 5.0 x 10(6); poly(ethylene oxide)poly(propylene oxide) block copolymer having M.W. 1.625 x 10(4); N,N,N,N',N',N'-hexamethylhexamethylenediammonium bromide (HMB); benzyl(diisobutylphenoxyethoxy) dimethylammonium chloride; hexadecyltrimethylammonium bromide; tetrabutylammonium chloride (TBAC); hexadecyldimethylbenzylammonium chloride, hexadecyltributylphosphonium bromide; tetraphenylphosphonium bromide; sodium dodecylsulphate; sodium stearate; sodium dodecylbenzenesulphonate; sodium octadecyloxyethylene ether sulphate; sodium octadecyloxyethylene ether malonate (Malester). Except for TBAC and HMB all the surfactants investigated decreased the titanium peak, although to different degrees. Generally the effect increased in the sequence cationic surfactants < non-ionic surfactants < anionic surfactants. The more hydrophobic non-ionic surfactants decreased the titanium peak more strongly than did the less hydrophobic ones. Malester was found the best of the investigated surfactants for this purpose. Sodium dodecylbenzenesulphonate also gave good results, although in this case an additional peak appeared. In the presence of these last two surfactants iron(III) does not substantially disturb the base-line current.
Talanta, 1988
Conditions have been found which make possible the determination of copper in the presence of a l... more Conditions have been found which make possible the determination of copper in the presence of a large excess of bismuth by differential-pulse and anodic-stripping voltammetry without preliminary separation. The electrochemical activity of the bismuth, which usually interferes in the determination of copper, is inhibited by using tetrabutylammonium chloride (TBAC) as surfactant. In 0.2M EDTA and 0.01M ascorbic acid at pH 4.5 as supporting electrolyte without the surfactant present, trace levels of copper (1.5 x 10(-8)M) can be determined accurately if the molar ratio of bismuth to copper is not higher than 3, but if the electrolyte also contains TBAC at 0.01M concentration, bismuth can be tolerated in concentrations up to 10(-4)M, and the height of the copper peak is unaffected.
Talanta, 1985
The determination of trace levels of thallium in bismuth and bismuth salts by differential pulse ... more The determination of trace levels of thallium in bismuth and bismuth salts by differential pulse anodlc-stripping voltammetry has been made possible by using a surfactant as an electrochemical masking agent, in addition to a complexing agent. In 0.2M EDTA at pH 4.5 as supporting electrolyte in the absence of surfactant, bismuth at concentrations
Planta, 2006
Huge advances achieved recently in elucidating the role of NO in plants have been made possible b... more Huge advances achieved recently in elucidating the role of NO in plants have been made possible by the application of NO donors. However, the application of NO to plants in various forms and doses should be subjected to detailed veriWcation criteria. Not all metabolic responses induced by NO donors are reliable and reproducible in other experimental designs. The aim of the presented studies was to investigate the halflife of the most frequently applied donors (SNP, SNAP and GSNO), the rate of NO release under the inXuence of light and reducing agents. At a comparable donor concentration (500 M) and under light conditions the highest rate of NO generation was found for SNAP, followed by GSNO and SNP. The measured half-life of the donor in the solution was 3 h for SNAP, 7 h for GSNO and 12 h for SNP. A temporary lack of light inhibited NO release from SNP, both in the solution and SNP-treated leaf tissue, which was measured by the electrochemical method. Also a NO, selective Xuorescence indicator DAF-2DA in leaves supplied with diVerent donors showed green Xuorescence spots in the epidermal cells mainly in the light. SNP as a NO donor was the most photosensitive. The activity of PAL, which plays an important role in plant defence, was also activated by SNP in the light, not in the dark. S-nitrosothiols (SNAP and GSNO) also underwent photodegra-dation, although to a lesser degree than SNP. Additionally, NO generation capacity from S-nitrosothiols was shown in the presence of reducing agents, i.e. ascorbic acid and GSH, and the absence of light. The authors of this paper would like to polemicize with the commonly cited statement that "donors are compounds that spontaneously break down to release NO" and wish to point out the fact that the process of donor decomposition depends on the numerous external factors. It may be additionally stimulated or inhibited by live plant tissue, thus it is necessary to take into consideration these aspects and monitor the amount of NO released by the donor.
Journal of Power Sources, 2011
Novel oxygen-doped activated carbon fiber cloths (OACFC), with different compositions of surface ... more Novel oxygen-doped activated carbon fiber cloths (OACFC), with different compositions of surface oxygen functionalities, have been prepared by direct electrooxidative/reductive methods in an undivided electrolytic cell filled with high purity water without a supporting electrolyte under high voltage conditions. The morphology and surface chemical composition of the materials have been investigated by SEM, Raman and XPS spectroscopies. They revealed an electrochemical erosion of the CF surface upon activation, concomitant with a strong change of the D/G ratio of characteristic Raman bands and the surface O/C atomic ratio, respectively. Thus pretreated material was tested as electrodes for an electrochemical capacitor by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 3.75 M H 2 SO 4. The performance of the electrochemical capacitor based on modified carbon electrodes was compared to that of an analogous device with unmodified carbon. The measurements revealed altered electrochemical behavior of the OACFC in terms of the determined capacitances. The proposed activation method is also superior to other electrochemical activation procedures, since it uses much less energy per CF surface or mass.
Journal of Power Sources, 2010
Activated carbon (AC) fiber cloths and hydrophobic microporous polypropylene (PP) membrane, both ... more Activated carbon (AC) fiber cloths and hydrophobic microporous polypropylene (PP) membrane, both modified by plasma-induced graft polymerization of acrylic acid (AAc) under UV irradiation, and filled with saturated lithium hydroxide solution were used as electrodes, a separator and electrolyte in electric double layer capacitors (EDLCs). The modification process changed the hydrophobic character of AC and PP materials to hydrophilic, made them wettable and serviceable as components of an electrochemical capacitor. The presence of poly(acrylic acid) on the AC and PP surface was confirmed by SEM and XPS methods. Electrochemical characteristics of EDLCs were investigated by cyclic voltammetry and galvanostatic charge-discharge cycle tests and also by impedance spectroscopy. At the 1000th cycle of potential cycling (1 A g −1) the specific capacitance of 110 F g −1 was obtained with a specific energy of 11 Wh kg −1 at power density of 1 kW kg −1. The above results provide valuable information which may be used when developing novel compositions of EDLCs.
Electroanalysis, 2003
Guaiacol (2-methoxyphenol) and its 5 derivatives such as 4-allyl-2-methoxyphenol,2-methoxy-4-prop... more Guaiacol (2-methoxyphenol) and its 5 derivatives such as 4-allyl-2-methoxyphenol,2-methoxy-4-propenylphenol, 2methoxy-4-propylphenol, 4-hydroxy-3-methoxybenzylamine and 4-chloro-2-methoxyphenol were oxidatively polymerized on platinum electrodes in 0.1 M NaOH solution. The polymer modified electrodes were then checked for their responses towards biologically important analytes such as hydrogen peroxide, ascorbic and uric acids, dopamine and acetaminophen under flow injection conditions. The effect of a monomer chosen on the permselective properties of the deposited film is thoroughly discussed. Feasibility of the application of these polymer modified electrodes in selective flow injection detection of hydrogen peroxide and dopamine is demonstrated.
Electroanalysis, 2005
Ni(II) and Co(II) phthalocyanines were deposited from their solutions in pyridine. The resulting ... more Ni(II) and Co(II) phthalocyanines were deposited from their solutions in pyridine. The resulting modified electrodes exhibited catalytic activity in alkaline media.
Electroanalysis, 1996
This communication assesses the role of nickel in the electrocatalytic detection of nitric oxide ... more This communication assesses the role of nickel in the electrocatalytic detection of nitric oxide at polymeric porphyrin coated glossy carbon electrodes.
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Papers by Aleksander Ciszewski