Zor, ErhanOztekin, YaseminMikoliunaite, LinaVoronovic, JaroslavRamanaviciene, AlmiraAnusevicius, ZilvinasBingol, Haluk2020-03-262020-03-2620141432-84881433-0768https://dx.doi.org/10.1007/s10008-013-2368-9https://hdl.handle.net/20.500.12395/30522In this study, two ortho-quinoidal compounds, 1,10-phenanthroline-5,6-dione (PD) and 9,10-phenanthrenequinone (PQ), were examined as electron transfer mediators suitable for amperometric glucose biosensors. The dependences of the electrochemical responses of PD- and PQ-based amperometric glucose biosensors on varied concentrations of glucose were investigated under aerobic and anaerobic conditions. The PD-modified graphite rod (GR) electrode revealed a current response seven times higher than that of the PQ-modified GR electrode. The reactivity indices of ortho-quinoidals assessed by means of B3LYP functional method applying 6-311G(D) basis set showed that the electron-accepting potency for PD was markedly higher as compared with that of PQ. Compared to PQ, considerably higher reactivity of PD has been defined in the reactions with NADP(+)-ferredoxin reductase (FNR, EC 1.18.1.2) as a model single-electron transfer FAD-dependent enzyme, which provided an additional evidence for PD as a more efficient mediator compared to PQ. This study illustrates that PD can be applied as a redox mediator for glucose oxidase and it could be more suitable for a reagent-less biosensor design than PQ.en10.1007/s10008-013-2368-9info:eu-repo/semantics/closedAccessElectrocatalysisGlucose sensorBiofuel cellGlucose oxidaseEnzyme electrodeQuinone derivativesArticle18615291536Q2WOS:000336390000005Q2