Direct electrochemical behavior of cytochrome c on DNA-modified glassy carbon electrode and its application to cytochrome c biosensor.
DNA was immobilized on glassy carbon electrodes to fabricate DNA-modified electrodes. The direct electron transfer of horse heart cytochrome c on DNA-modified glassy carbon electrode was achieved. A pair of well-defined redox peaks of cytochrome c appeared at Epc = -0.017 V and Epa = 0.009 V (vs. Ag/AgCl) in 10 mM phosphate buffer solution (pH 7.0) at a scan rate of 50 mV/s. The electron transfer coefficient (alpha) and the standard rate constant of the surface reaction (Ks) of cytochrome c on DNA-modified electrodes could be estimated to be 0.87 and 34.52 s(-1), respectively. The DNA-modified glassy carbon electrode could be applied to detect cytochrome c by means of differential pulse voltammetry (DPV). The cathodic peak current was proportional to the quantity of cytochrome c in the range of 4.0 x 10(-6) M to 1.2 x 10(-5) M. The correlation coefficient is 0.996, and with the detection limit was 1.0 x 10(-6) M (three times the ratio of signal to noise, S/N = 3).
Liu
Yun-Chun
YC
School of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu, PR China.
Cui
Shi-Qiang
SQ
Yang
Zhou-Sheng
ZS
D015374:Biosensing Techniques; D002138:Calibration; D002244:Carbon / Q000737:chemistry*; D045304:Cytochromes c / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013499:Surface Properties
D004800:Enzymes, Immobilized; D002244:Carbon; D045304:Cytochromes c; D004247:DNA