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1.
Herrasti P. Mazarío E. Recio Francisco J. 《Journal of Solid State Electrochemistry》2021,25(1):231-236
Journal of Solid State Electrochemistry - In this work, the use of neodymium electrodes as a basis for the immobilization of magnetite nanoparticles has been carried out. The sensitivity and... 相似文献
2.
Hybrid composites ZnO/PANI were facily synthesized by a sonication process at room temperature. This procedure is non-expensive, time/energy saving and environmentally safe. The as-prepared ZnO/PANI were characterized by FTIR, UV-vis spectroscopies and SEM in order to investigate the structure and morphology of the studied composites. The samples were used to modify carbon paste electrode (CPE) in order to develop electrochemical biosensors (ZnO/PANI/CPE). The sensing properties of the nanoparticles were evaluated for dopamine, ascorbic acid and uric acid non-enzymatic detection. The effect of percentage of polyaniline in the composites and the effect of calcination on the biosensor's response were also examined in the present study. It was revealed that the existence of PANI in ZnO/PANI/CPE largely enhanced the electroactive surface area and therefore the sensitivity for electrochemical sensing. A good electrochemical behavior was noted for ZnO/40 wt% PANI-cal/CPE modified electrode toward DA, AA and UA oxidation. The electroactive surface area of the previously mentioned modified electrode (0.235 cm2) was two times higher than that of the bare electrode (0.117 cm2). The liner relationships between current intensities and concentrations were found to be 0.01–1.4 mM, 0.1–1.3 mM and 0.01–0.12 mM, with detection limit of 0.029 mM, 0.063 mM and 0.007 mM, for DA, AA and UA respectively. In the mixtures of ascorbic acid (AA), dopamine (DA) uric acid (UA) and glucose (Glu) the sensor showed high selectivity of DA with low interference of ascorbic acid by a current change of 14 %. The as-prepared ZnO/PANI/CPE biosensor displayed a good reproducibility and stability. 相似文献
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López C. Herrasti P. Sánchez M. Casillas N. 《Journal of Solid State Electrochemistry》2017,21(11):3345-3354
Journal of Solid State Electrochemistry - In this work, an electrochemical modified microcell is proposed to obtain local mass transfer coefficients at microscopic electrode areas. Microcell... 相似文献
5.
Fausto N. Comba María D. Rubianes Lourdes Cabrera Silvia Gutiérrez Pilar Herrasti Gustavo A. Rivas 《Electroanalysis》2010,22(14):1566-1572
This work reports the advantages of carbon paste electrodes modified with electrogenerated magnetite nanoparticles. The nanoparticles present catalytic activity towards hydrogen peroxide reduction. The incorporation of glucose oxidase (GOx) and magnetite in a carbon paste matrix have made possible the development of an efficient glucose biosensor. The effect of the amount of GOx and magnetite present in the composite on the response of the biosensor was critically evaluated. The biosensors demonstrated to be highly selective, with negligible interference of ascorbic acid and uric acid. The proposed biosensor was challenged with human blood serum demonstrating an excellent correlation with the spectrophotometric method. 相似文献
6.
Lourdes I. Cabrera Marta Martínez Dolores Reyman Patricia Crespo M. Puerto Morales Pilar Herrasti 《Journal of nanoparticle research》2011,13(12):6931-6939
This work reports the preparation of hybrid nanoparticles with magnetic and fluorescent properties. The material is based
on magnetite nanoparticles (NPs) coated with fluorophore methylene blue (MB). The synthesis of a multifunctional material
with magnetic and fluorescent features is carried out in a single step by electrooxidation. The effect of the presence of
methylene blue in the synthetic medium is discussed. The presence of MB polymer at the NP surface is demonstrated with visible
UV, infrared and Raman spectroscopy. The NPs morphology, structure and size are determined by transmission electron microscopy
(TEM) and X-ray diffraction. The magnetic properties are measured with a vibrating sample magnetometer (VMS). In overall,
the results show that magnetite NPs generated electrochemically in the presence of MB present a core/shell structure, being
the NP at the core surrounded by methylene blue polymer, leading to a nanocomposite or hybrid material. 相似文献
7.
Zorione Herrasti Fernando Martínez Eva Baldrich 《Analytical and bioanalytical chemistry》2014,406(22):5487-5493
In this work, chronoamperometric myelo-peroxidase (MPO) detection was accomplished using immunofunctionalized magnetic microparticles (MPs), disposable carbon screen-printed electrodes (C-SPEs), and a ready-to-use commercially available tetramethylbenzidine (TMB)-based enzymatic substrate. In order to reach the limit of detection (LOD) needed to study real blood serum samples, assay performance was additionally improved by exploiting CNT wiring, which amplified the signal and decreased the LOD. The optimized assay can be performed in 30 min and yields LODs of 6 and 55 ng mL?1 in PBS and undiluted human serum, respectively, making it useful for the identification of patients at risk of cardiovascular disease. These results demonstrate that electrode nanostructuring can be accomplished “post-assay,” which favors the development of enhanced magneto immunosensors based on the exploitation of cheap and simple SPE devices. 相似文献
8.
B. Alshammary F. C. Walsh P. Herrasti C. Ponce de Leon 《Journal of Solid State Electrochemistry》2016,20(4):839-859
Over the last 40 years, electrically conductive polymers have become well established as important electrode materials. Polyanilines, polythiophenes and polypyrroles have received particular attention due to their ease of synthesis, chemical stability, mechanical robustness and the ability to tailor their properties. Electrochemical synthesis of these materials as films have proved to be a robust and simple way to realise surface layers with controlled thickness, electrical conductivity and ion transport. In the last decade, the biomedical compatibility of electrodeposited polymers has become recognised; in particular, polypyrroles have been studied extensively and can provide an effective route to pharmaceutical drug release. The factors controlling the electrodeposition of this polymer from practical electrolytes are considered in this review including electrolyte composition and operating conditions such as the temperature and electrode potential. Voltammetry and current-time behaviour are seen to be effective techniques for film characterisation during and after their formation. The degree of take-up and the rate of drug release depend greatly on the structure, composition and oxidation state of the polymer film. Specialised aspects are considered, including galvanic cells with a Mg anode, use of catalytic nanomotors or implantable biofuel cells for a self-powered drug delivery system and nanoporous surfaces and nanostructures. Following a survey of polymer and drug types, progress in this field is summarised and aspects requiring further research are highlighted. 相似文献
9.
Electrodeposition of polythiophene assisted by sonochemistry and incorporation of fluorophores in the polymeric matrix 总被引:2,自引:0,他引:2
This work studies the effect of an ultrasonic field of 530 kHz frequency on the electrodeposition of polythiophene in an acetonitrile solution using lithium perchlorate as background electrolyte. The results obtained show an increase in the polymer mass transfer produced and a more compact and homogenous morphology of the films yielded by sonoelectrochemistry. Electrodeposition of the polymer was also carried out in the presence of the fluorophores Harmane (1-methyl-9H-pyrido[3,4-b]indole) or BCCM (9H-pyrido[3,4-b]indole-3-carboxylic acid methyl ester). Confocal microscopy measurements performed on the films synthesised in the presence of these compounds showed that the latter are embedded in the polymer when it is sonoelectrogenerated at a potential of 2.2, 2.5 or 2.8 V. Films generated in the absence of ultrasound showed no fluorescence. 相似文献
10.
Jaime-González J. Mazario E. Menendez N. Sanchez-Marcos J. Muñoz-Bonilla A. Herrasti P. 《Journal of Solid State Electrochemistry》2016,20(4):1191-1198
Journal of Solid State Electrochemistry - Ferrites of iron, cobalt, and nickel were used as a non-enzymatic sensor for detection of hydrogen peroxide. X-ray diffraction (XRD) and transmission... 相似文献