Determination of cytochrome C with cellulose - DNA modified carbon paste electrodes

A sensor for cytochrome c (cyt c) was developed using a carbon paste electrode (CPE) modified with cellulose-DNA. Cyt c was adsorbed on the cellulose-DNA modified CPE through the electrostatic interaction between them. Owing to this process, a pair of well-defined peaks appeared at + 48 mV/85 mV (E-pc/E-pa vs. Ag/AgCl). This property of the cellulose-DNA modified CPE was utilized for the analysis of cyt c in a biological sample. The optimum experimental conditions for analysis were investigated and a calibration plot was obtained between 1.0 x 10(-4) M and 1.0 x 10(-6) M (+/-5% at n = 5) at the optimized condition. The detection limit for cyt c at the optimized experimental condition was 5.0 x 10(-7) M (S/N = 3) for 30 min of deposition time with differential pulse voltammetry (DPV). The real sample analysis was carried out with the standard addition method to evaluate the developed method. The content of cyt c in total proteins of 80.0 mg/mL in rat mitocondria fractions was determined to be 0.12 (+/-0.02) mg/mL.