TY - JOUR AU - Szerencsés, Bettina AU - Igaz, Nóra AU - Tóbiás, Ákos AU - Prucsi, Zsombor AU - Rónavári, Andrea AU - Bélteky, Péter AU - Madarász, Dániel AU - Papp, Csaba Gergő AU - Makra, Ildikó AU - Vágvölgyi, Csaba AU - Kónya, Zoltán AU - Pfeiffer, Ilona AU - Csontné Kiricsi, Mónika TI - Size-dependent activity of silver nanoparticles on the morphological switch and biofilm formation of opportunistic pathogenic yeasts JF - BMC MICROBIOLOGY J2 - BMC MICROBIOL VL - 20 PY - 2020 IS - 1 PG - 13 SN - 1471-2180 DO - 10.1186/s12866-020-01858-9 UR - https://m2.mtmt.hu/api/publication/31353819 ID - 31353819 N1 - Department of Microbiology, University of Szeged, Szeged, Hungary Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged, H-6726, Hungary Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary HAS-USZ Reaction Kinetics and Surface Chemistry Research Group, Szeged, Hungary Cited By :2 Export Date: 31 May 2021 Correspondence Address: Kiricsi, M.; Department of Biochemistry and Molecular Biology, Közép fasor 52, Hungary; email: kiricsim@gmail.com LA - English DB - MTMT ER - TY - JOUR AU - Guzsvány, Valéria AU - Anojčić, J. AU - Vajdle, O. AU - Radulović, E. AU - Madarász, Dániel AU - Kónya, Zoltán AU - Kalcher, K. TI - Amperometric Determination of Glucose in White Grape and in Tablets as Ingredient by Screen-Printed Electrode Modified with Glucose Oxidase and Composite of Platinum and Multiwalled Carbon Nanotubes JF - FOOD ANALYTICAL METHODS J2 - FOOD ANAL METHOD VL - 12 ET - 0 PY - 2019 IS - 2 SP - 570 EP - 580 PG - 11 SN - 1936-9751 DO - 10.1007/s12161-018-1387-7 UR - https://m2.mtmt.hu/api/publication/30316998 ID - 30316998 AB - Multiwalled carbon nanotubes (MWCNTs) and nanocomposite made from MWCNTs and Pt nanoparticles (Pt-MWCNTs) were used as bulk modifiers of screen-printed carbon electrodes (SPCEs). Cyclic voltammetric and amperometric measurements were performed by the homemade substrate electrodes, the bare SPCE and the modified ones (MWCNT-SPCE and Pt-MWCNT-SPCE), with aim to investigate their applicability for determination of H2O2 in phosphate buffer solution (0.1 M; pH 7.50) as supporting electrolyte. Pt-MWCNT-SPCE showed improved analytical performances including the significant decrease in overpotential of H2O2 compared to SPCE and MWCNT-SPCE. So, Pt-MWCNT-SPCE served as substrate electrode for design of a simple first-generation biosensor made from glucose oxidase (GOx) and Nafion® forming the GOx/Pt-MWCNT-SPCE for reliable determination of glucose via its enzymatic by-product, the H2O2. The surface morphology characterization by scanning electron microscopy confirmed the presence of immobilized spherical shaped biosensing units at the GOx/Pt-MWCNT-SPCE. In the case of amperometry of glucose, optimal potential for the working electrode was − 0.50 V vs. SCE, and a satisfactory linearity was obtained in the tested concentration range from 65.8 to 260.6 μg mL−1, with estimated LOQ of 35.0 μg mL−1. The developed cost-effective amperometric method in combination with GOx/Pt-MWCNT-SPCE was successfully applied for the determination of glucose in selected food samples: white grapes and glucose tablets. The obtained results were in good agreement with those received by the alternatively used commercially available glucometer and by the producer declared value in the case of the tablet sample as well. © 2018, Springer Science+Business Media, LLC, part of Springer Nature. LA - English DB - MTMT ER - TY - THES AU - Madarász, Dániel TI - Egydimenziós titanát nanoszerkezetek módosításának lehetőségei PB - Szegedi Tudományegyetem (SZTE) PY - 2018 SP - 92 DO - 10.14232/phd.9722 UR - https://m2.mtmt.hu/api/publication/30617557 ID - 30617557 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Budai, Dénes AU - Vizvári, Attila D. AU - Bali, Zsolt Kristóf AU - Márki, Balázs AU - Nagy, Lili Veronika AU - Kónya, Zoltán AU - Madarász, Dániel AU - Henn-Mike, Nóra AU - Varga, Csaba AU - Hernádi, István TI - A novel carbon tipped single micro-optrode for combined optogenetics and electrophysiology JF - PLOS ONE J2 - PLOS ONE VL - 13 PY - 2018 IS - 3 PG - 22 SN - 1932-6203 DO - 10.1371/journal.pone.0193836 UR - https://m2.mtmt.hu/api/publication/3344917 ID - 3344917 AB - Optical microelectrodes (optrodes) are used in neuroscience to transmit light into the brain of a genetically modified animal to evoke and record electrical activity from light-sensitive neurons. Our novel micro-optrode solution integrates a light- transmitting 125 micrometer optical fiber and a 9 micrometer carbon monofilament to form an electrical lead element, which is contained in a borosilicate glass sheathing coaxial arrangement ending with a micrometer-sized carbon tip. This novel unit design is stiff and slender enough to be used for targeting deep brain areas, and may cause less tissue damage compared with previous models. The center-positioned carbon fiber is less prone to light-induced artifacts than side-lit metal microelectrodes previously presented. The carbon tip is capable of not only recording electrical signals of neuronal origin but can also provide valuable surface area for electron transfer, which is essential in electrochemical (voltammetry, amperometry) or microbiosensor applications. We present details of design and manufacture as well as operational examples of the newly developed single micro- optrode, which includes assessments of 1) carbon tip length–impedance relationship, 2) light transmission capabilities, 3) photoelectric artifacts in carbon fibers, 4) responses to dopamine using fast-scan cyclic voltammetry in vivo, and 5) optogenetic stimulation and spike or local field potential recording from the rat brain transfected with channelrhodopsin-2. With this work, we demonstrate that our novel carbon tipped single micro-optrode may open up new avenues for use in optogenetic stimulation when needing to be combined with extracellular recording, electrochemical, or microbiosensor measurements performed on a millisecond basis. LA - English DB - MTMT ER - TY - JOUR AU - Tari, Tímea AU - Ambrus, Rita AU - Szakonyi, Gerda AU - Madarász, Dániel AU - Frohberg, P AU - Pannonhalminé Csóka, Ildikó AU - Révész, Piroska AU - Ulrich, J AU - Aigner, Zoltán TI - Optimizing the crystal habit of glycine by using an additive for impinging jet crystallization JF - CHEMICAL ENGINEERING & TECHNOLOGY J2 - CHEM ENG TECHNOL VL - 40 PY - 2017 IS - 7 SP - 1323 EP - 1331 PG - 9 SN - 0930-7516 DO - 10.1002/ceat.201600634 UR - https://m2.mtmt.hu/api/publication/3231738 ID - 3231738 LA - English DB - MTMT ER - TY - JOUR AU - Madarász, Dániel AU - Kukovecz, Ákos AU - Kiss, János AU - Kónya, Zoltán TI - Titanát nanoszerkezetek és fémek felületi kölcsönhatásai: ioncsere vagy klaszterképződés? JF - MAGYAR KÉMIAI FOLYÓIRAT - KÉMIAI KÖZLEMÉNYEK (1997-) J2 - MAGY KÉM FOLY KÉM KÖZL VL - 123 PY - 2017 IS - 1 SP - 13 EP - 20 PG - 8 SN - 1418-9933 DO - 10.24100/MKF.2017.01.13 UR - https://m2.mtmt.hu/api/publication/3218138 ID - 3218138 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Guzsvány, Valéria AU - Anojčić, Jasmina AU - Radulović, Emil AU - Vajdle, Olga AU - Stanković, Igor AU - Madarász, Dániel AU - Kónya, Zoltán AU - Kalcher, Kurt TI - Screen-printed enzymatic glucose biosensor based on a composite made from multiwalled carbon nanotubes and palladium containing particles JF - MICROCHIMICA ACTA J2 - MICROCHIM ACTA VL - 184 PY - 2017 IS - 7 SP - 1987 EP - 1996 PG - 10 SN - 0026-3672 DO - 10.1007/s00604-017-2188-1 UR - https://m2.mtmt.hu/api/publication/3207003 ID - 3207003 AB - A composite material consisting of multiwalled carbon nanotubes and palladium containing particles was synthesized and applied to the preparation of bulk-modified screen-printed carbon electrodes (Pd-MWCNT-SPCE) and surface-modified screen-printed carbon electrodes (Pd-MWCNT/SPCE). They were characterized by cyclic voltammetry and hydrodynamic chronoamperometry in solution of pH 7.5. Both electrodes were then modified with glucose oxidase (GOx) by drop-coating a solution of GOx and Nafion® on their surface. Glucose can be determined via enzymatically formed H2O2. In an alternative approach, gold nanoparticles (5 nm) were incorporated into the biolayer of the electrodes. The resulting electrodes of type GOx/Pd-MWCNT-SPCE and GOx-Au/Pd-MWCNT-SPCE showed acceptable analytical performance at working potentials between −0.20 V and −0.50 V in case of hydrodynamic chronoamperometry. Both electrodes can be operated best at a working potential of −0.40 V vs SCE, with acceptable linearity of the methods in sub mM concentration ranges and with LOQs of 0.14 mM and 0.07 mM for glucose for the GOx/Pd-MWCNT-SPCE and GOx-Au/Pd-MWCNT-SPCE, respectively. Incorporation of gold nanoparticles prolongs the operational lifetime of the electrodes by two weeks. The GOx/Pd-MWCNT-SPCE based method was applied to the determination of glucose in multifloral honey, and the GOx-Au/Pd-MWCNT-SPCE method to the determination of glucose in blood serum. In both cases there was a good agreement with the results obtained by commercially available equipment for determination of glucose. LA - English DB - MTMT ER - TY - JOUR AU - Gilicze, Barnabás AU - Moczok, M AU - Madarász, Dániel AU - Juhasz, N AU - Racsko, B AU - Nánai, László TI - Periodic surface structure creation by UV femtosecond pulses on silicon JF - AIP CONFERENCE PROCEEDINGS J2 - AIP CONF PROC VL - 1796 PY - 2017 SN - 9780735414624 SN - 0094-243X DO - 10.1063/1.4972366 UR - https://m2.mtmt.hu/api/publication/3187830 ID - 3187830 LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Dávid AU - Igaz, Nóra AU - Csilla, Keskeny AU - Bélteky, Péter AU - Tímea, Tóth AU - Molnár-Gáspár, Renáta AU - Madarász, Dániel AU - Rázga, Zsolt AU - Kónya, Zoltán AU - Boros, Imre Miklós AU - Csontné Kiricsi, Mónika TI - Silver nanoparticles defeat p53-positive and p53-negative osteosarcoma cells by triggering mitochondrial stress and apoptosis JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 6 PY - 2016 PG - 13 SN - 2045-2322 DO - 10.1038/srep27902 UR - https://m2.mtmt.hu/api/publication/3079142 ID - 3079142 LA - English DB - MTMT ER - TY - JOUR AU - Anojčić, Jasmina AU - Guzsvány, Valéria AU - Vajdle, Olga AU - Madarász, Dániel AU - Rónavári, Andrea AU - Kónya, Zoltán AU - Kalcher, Kurt TI - Hydrodynamic chronoamperometric determination of hydrogen peroxide using carbon paste electrodes coated by multiwalled carbon nanotubes decorated with MnO2 or Pt particles JF - SENSORS AND ACTUATORS B-CHEMICAL J2 - SENSOR ACTUAT B CHEM VL - 233 PY - 2016 SP - 83 EP - 92 PG - 10 SN - 0925-4005 DO - 10.1016/j.snb.2016.04.005 UR - https://m2.mtmt.hu/api/publication/3045663 ID - 3045663 AB - Abstract In this comparative study a traditional paraffin oil and graphite powder based carbon paste electrode (CPE) was surface modified with multiwalled carbon nanotubes (MWCNTs) and with composites of MnO2-MWCNT or Pt-MWCNT by drop coating method to prepare simply, sensitive and reliable voltammetric sensors either for the determination of H2O2 or after additional modification of the appropriate sensor surfaces with glucose oxidase (GOx) for the determination of glucose via H2O2 in selected samples. The scanning electron microscopic characterization in combination with energy dispersive X-ray spectrometry of the composite materials confirmed that the mediators, MnO2 and Pt, are randomly distributed on the surface of the MWCNTs, and in both cases represent nearly 5% (m: m) of the modifiers expressed as Pt and Mn. Cyclic voltammetric (CV) investigations were performed in acetate (pH 4.50), phosphate (pH 7.50) and borate (pH 9.18) buffers to characterize the basic electrochemical behaviors and to select the working potentials suitable for hydrodynamic chronoamperometric (HA) determination of H2O2 under different circumstances. The CV responses showed that in slightly alkaline media all investigated electrodes, i.e., CPEs unmodified and modified with plain MWCNTs and MWCNTs based composites are in principle applicable, but with different efficiency at different potentials, with favorable reduction and acceptable oxidation of H2O2 at the Pt-MWCNT/CPE and predominately oxidation at the MnO2-MWCNT/CPE. The reproducibility of the responses with the MnO2-MWCNT/CPE is poor, but can be improved by electrochemical conditioning. The latter one performed well in alkaline supporting electrolyte (pH 9.18), while in the case of the Pt-MWCNT/CPE the signals are much better established in slightly acidic medium (pH 4.50). The analytical methods were optimized, mainly with the Pt-MWCNT/CPE as the preferential electrode, in terms of pH and working potential for the HA determination of H2O2 in spiked milk samples including the development of an appropriate sample treatment procedure. This electrode was also used for the design of a very simple and reliable first generation oxidase biosensor for determination of glucose content in human infusion via its enzymatic reaction product H2O2. LA - English DB - MTMT ER -