A highly sensitive sensor based on a carbon paste electrode modified with a CdO nanoparticle and 1-methyl-3-
butylimidazolium bromide was used for the voltammetric analysis of vitamin C in the presence of nicotin
amide adenine dinucleotide. The highly sensitive sensor shows excellent enhancement and electrocatalytic
activity towards vitamin C. The variation of pH shows the number of protons is equal to number of electrons
for vitamin C electrooxidation. The electrooxidation peak current of vitamin C and nicotin amide adenine
dinucleotide increased linearly with their concentration in the ranges of 0.07–480 μmol L−1 vitamin C and
0.5–700 μmol L−1 nicotin amide adenine dinucleotide. The limits of detection for vitamin C and nicotin amide
adenine dinucleotidewere 0.03 μmol L−1 and 0.1 μmol L−1, respectively. Simultaneous determination of vitamin
C and nicotin amide adenine dinucleotide was investigated by using the square wave voltammetry technique.
The proposed sensor showed good stability, sensitivity, selectivity, and reproducibility and can be used for
some important food sample analyses.