Yazar "Guenes, Mehmet" seçeneğine göre listele

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    Development of an interference-minimized amperometric-FIA glucose biosensor at a pyrocatechol violet/glucose dehydrogenase-modified graphite pencil electrode
    (Springer International Publishing Ag, 2020) Guenes, Mehmet; Karakaya, Serkan; Dilgin, Yusuf
    A modified disposable electrode formed by immobilization of glucose dehydrogenase (DHG) onto pyrocatechol violet (Pcv)-modified graphite pencil electrode (GPE) was proposed for the flow injection (FI) amperometric glucose biosensor. Cyclic voltammetric experiments show that Pcv illustrates a good electrocatalytic effect towards the oxidation of enzymatically produced NADH. Although electrocatalytic oxidation of enzymatically generated NADH at the DHG/Poly-Pcv/GPE was successfully performed at + 250 mV in FIA system, some molecules such as ascorbic acid (AA), dopamine (DA) and uric acid (UA) give a significant positive interference due to their oxidation at this working potential. To overcome these interferences, an injector filled with a pre-oxidant, sodium bismuthate (NaBiO3), was used in the FI amperometric glucose biosensor at the DHG/Poly-Pcv/GPE. Results showed that the interferences of these molecules were significantly minimized, because they were oxidized by NaBiO3 in the injector before reaching the electrode surface in the flow cell. The constructed biosensor showed that a linear calibration curve was obtained in the range between 5.0 mu M and 500 mu M glucose with a detection limit of 1.2 mu M. This proposed glucose biosensor including elimination of interferences of some oxidizable species was successfully applied to the real and artificial samples.
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    Öğe
    Sensitive voltammetric detection of acetaminophen at electropolymerized bromophenol red film-coated pencil graphite
    (Springer Wien, 2023) Guenes, Mehmet
    In this study, a new sensitive electrochemical sensor was developed for the sensitive determination of acetaminophen (ACPN) at an electrochemically coated bromophenol red (PolyBFR) modified pencil graphite electrode (PGE). The modified electrode (PolyBFR-PGE) displayed a considerable increase in electrochemical response for the oxidation of ACPN, compared to the unmodified PGE. The electrochemical behavior of ACPN was determined by cyclic voltammetry and linear sweep voltammetry methods at PolyBFR-PGE. The effect of some parameters on the voltammetric response (monomer concentration, cycle number, and pH) was optimized for the voltammetric determination of ACPN. PolyBFR-PGE determines the ACPN in a wide linear segment from 0.25 to 3500 mu M. Furthermore, the limit of detection and sensitivity were found as 0.088 mu M ACPN and 1421.4 mu A mM(-1) cm(-2), respectively. The designed voltammetric ACPN sensor was successfully applied to pharmaceutical formulations and artificial samples, and satisfactory results were obtained with high accuracy and precision. [GRAPHICS] .