Kılıç, Muhammet Samet | Korkut, Şeyda | Hazer, Baki

Article | 2017 | Electroanalysis29 ( 10 ) , pp.2377 - 2384

Newly synthesized poly(styrene-g-oleic amide) was coated onto a rhodium nanoparticle modified glassy carbon (GC) surface for the fabrication of horseradish peroxidase based biosensor used for hydrogen peroxide detection. The rhodium modifed electrode presented ten times higher signal than unmodified electrode even at low elecrtroactive enzyme quantity by enhancing the electron transfer rate at the applied potential of -0.65 V. The biosensor designed by under the optimized rhodium electrodeposition time exhibited a fast response less than 5 s, an excellent operational stability with a relative standard deviation of 0.6 % (n=6), an ac . . .curacy of 96 % and a large linear range between 50 µM and 120 mM for hydrogen peroxide. Detection limit and the sensitivity parameters were calculated to be 44 µM and 57 µA mM-1 cm-2, respectively by preserving its entire initial response up to the 15 days, while only 20 % of its initial response was lost at the end of one month. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei Daha fazlası Daha az

Korkut, Şeyda | Göl, Saliha | Kılıç, Muhammet Samet

Article | 2019 | Electroanalysis , pp.2377 - 2384

A biosensor based on conductive poly(pyrrole-co-pyrrole-2-carboxylic acid) [Poly(Py-co-PyCOOH)] copolymer film coated gold electrode was developed for the quantitative phosphate determination. Enzyme pyruvate oxidase was immobilized chemically via the functional carboxylated groups of the copolymer. The potential to be applied which is deficiency of phosphate biosensor studies for precise phosphate detection was clarified by using differential pulse voltammetry technique. Performance of the sensing ability of the biosensor was improved by optimizing cofactor/cosubstrate concentrations, polymeric film density and pH. The biosensor sh . . .owed a linearity up to phosphate concentration of 5 mM, operational stability with a relative standard deviation (RSD) of 0.07 % (n=7) and accuracy of 101 % at -0.15 V (vs. Ag/AgCl). Detection limit (LOD) and sensitivity were calculated to be 13.3 µM and 5.4 µA mM-1 cm-2, respectively by preserving 50 % of its initial response at the end of 30 days. It's performance was tested to determine phosphate concentrations in two streams of Zonguldak City in Turkey. Accuracy of phosphate measurement in stream water was found to be 91 %. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei Daha fazlası Daha az