Differential pulse voltammetric determination and application of square-wave voltammetry of yRNA on a CPB-Cellulose modified electrode

Electrochemical behavior of remarkably low levels of Ribonucleic acid yeast (yRNA) is studied through differential pulse voltammetry (DPV), and kinetic parameters of the electrochemical reaction have also been calculated through square-wave voltammetry (SWV), based on immobilization of yRNA on the surface of a CPB-cellulose modified electrode. YRNA/ CPB-cetlulose/ITO conductive glass electrode is demonstrated by Infrared reflect (IR) and electrochemical impedance spectroscopy (EIS). The oxidation peak potential of yRNA shifts negatively with increasing pH. ne peak currents decrease gradually in successive scans and no corresponding reduction peaks occur, indicating that oxidation process of yRNA is completely irreversible. Variables influencing DPV response of yRNA, such as pH, pulse amplitude and electrolyte concentration, are explored and optimized. Peak currents are proportional to the concentration of yRNA in the range of 0.1 mu g mL(-1)-1.0 mu g mL(-1), and the linear regression coefficient equals 0.9923. The detection limit for yRNA is 1.0 x 10(-10) g mL(-1). Interferences of L-cysteine, L-alanine, Hemoglobin, Uridine 5 '-monophosphate, Guanosine 5 '-monophosphate, Adenosine 5 '-triphosphate and some metal ions (Co3+, Cr3+, Ni2+ Hg2+, Zn2+, etc) are negligible. The methods adopted here are more sensitive and selective than currently applied techniques and overcome the drawback of absorption spectroscopy arising from a strong interference due to other UV-absorbing substances.