Measurement of L-Cysteine Amino Acid Using Modified Platinum Electrode by Nickel-Aluminum layered double hydroxide

L-Cysine (L-Cys) is one of the most important amino acids in the body and plays an important role in the immune system. In this study, the platinum electrode was modified by a Ni-Al double-layer hydroxide film (Pt /NiAlLDH) and used to measure L-Cys. Pt/NiAlLDH showed good catalytic activity for the oxidation of L-Cys. On this electrode, the oxidation of L-Cys occurs at a potential very lower than an unmodified platinum electrode, which occurred at about 500 mV. The catalytic oxidation peak currents depend on the L-Cys concentration with a logarithmic linear relation in the concentration range of 1×10-7 to 2.5×10-4 M and an experimental detection limit of 1×10-7 M. The proposed electrode was used for determination of L-Cys in a drug sample. This modified electrode is cheap and is quickly and easily prepared.