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

Article | 2016 | Instrumentation Science and Technology44 ( 6 ) , pp.614 - 628

A novel continuous flow biosensor based on gold nanoparticles and poly(propylene-co-imidazole) was developed for the online determination of p-benzoquinone. The amperometric response was measured as a function of p-benzoquinone concentration at an applied potential of -50 mV. The hydrogen peroxide concentration was optimized and fixed at 1 mM in samples. The mass transfer resistance of the copolymer film was minimized, and the flow cell was regenerated quickly at 1 mL/min. The resulting device provided good analytical performance based on a linear dynamic range from 5–100 µM, a short response time of 3 s, a detection limit of 3.3 µM . . ., excellent repeatability with a relative standard deviation of 0.82%, long-term stability of 95% after four weeks, and an accuracy of 105%. The gold nanoparticles enhanced the electron transfer rate on the electrode. The apparent Michaelis-Menten constant was 4 mM, showing that the enzyme retained catalytic specificity and provided high activity for p-benzoquinone. © 2016, Taylor & Francis Daha fazlası Daha az

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

Article | 2019 | Instrumentation Science and Technology47 ( 1 ) , pp.1 - 18

A new amperometric urea biosensor based on gold nanoparticle embedded poly(propylene-co-imidazole) was developed for the determination of urea. The urease adsorbed on the polymeric film catalyzed the hydrolysis of urea to ammonium and bicarbonate ions and the ammonium was then electrooxidized on the gold electrode with the aid of gold nanoparticles at +0.2 V versus Ag/AgCl using differential pulse voltammetry. The biosensor provided a linear current response to urea concentration from 0.1 to 30 mM, a detection limit of 36 µM, a relative standard deviation of 2.43% (n = 18), and excellent storage stability, as the current decrease wa . . .s only 3% after 75 days. The operation of the biosensor was evaluated by the analysis of municipal sewage wastewater collected from the inlet pipe of the treatment plant of Zonguldak City in Turkey. The effects of possible interferants were also characterized. © 2018, © 2018 Taylor & Francis Daha fazlası Daha az

Kılıç, Muhammet Samet

Article | 2017 | Instrumentation Science and Technology45 ( 3 ) , pp.276 - 289

Poly[1-(2-aminophenyl) pyrrole] film was electropolymerized on a gold electrode and used for the first time as the matrix for the electrochemical determination of glucose. The working electrode where glucose oxidase was chemically immobilized by amine groups of the poly[1-(2-aminophenyl) pyrrole] film was used for online glucose determination with flow-injection operation. The optimum conditions for glucose were a flow rate of 4 mL/min at +0.7 V in 100 mM using pH 6.5 phosphate buffer as the carrier. The electrode provided a long linear dynamic range between 0.2 mM and 30 mM, a response time of 9 s, a detection limit of 63 µM, a rel . . .ative standard deviation of 0.7%, and an accuracy of 99.95%. The working electrode preserved 64% of its initial current value following six weeks. The optimized device was employed to determine glucose in wastewater from the Zonguldak Biological Treatment Plant, Turkey. © 2017, Copyright © Taylor & Francis Group, LLC Daha fazlası Daha az