Application of CdO nanoparticle ionic liquid modified carbon paste electrode as a high sensitive biosensor for square wave voltammetric determination of NADH.

In this paper we report the synthesis and application of CdO nanoparticle (CdO/NPs) and 1,3-dipropylimidazolium bromide as high sensitive sensors for voltammetric determination of nicotinamide adenine dinucleotide (NADH) using carbon paste electrode. The cyclic voltammogram showed an irreversible oxidation peak at 0.68 V (vs. Ag/AgClsat), which corresponded to the oxidation of NADH. Compared to common carbon paste electrode, the electrochemical response was greatly improved for NADH electrooxidation at a surface of CdO/NP modified ionic liquid carbon paste electrode (IL/CdO/NP/CPE). The linear response range and detection limit were found to be 0.09-750 μmol L(-1) and 0.05 μmol L(-1), respectively. Result shows that other physiological species did not interfere in the determination of NADH at the surface of the proposed sensor in the optimum condition. The proposed sensor was successfully applied for the determination of NADH in tap water, urine and pharmaceutical serum samples.