Abstract
In this work, nanocrystalline NiO thin films of high purity are fabricated by an easy and simple sol-gel method. Several technics were used to study structural, morphological and optical properties. They proved that the particles forming the thin films are homogeneous and of an average size of 9 nm. Concerning the electrochemical properties of NiO thin films, they were studied by Cyclic Voltammetry (CV) and amperometry. CV investigations revealed that NiO nanoparticles are highly sensitive to hydrogen peroxide at an over potential of 0.05 V (vs Ag/AgCl), and amperometry measurements showed that the proposed sensor exhibits an exceptional sensitivity of 1120 mu.A.mM(-1).cm(-2), a fast response time (1s) and a very low detection limit of 16nM. NiO electrode proposed in this work is easy to build, inexpensive and highly stable. The excellent sensitivity, the very low detection limit and the high selectivity at very low overpotential of 0.05 V, allow the proposed sensor to be an effective candidate for H2O2 in vivo monitoring in the fields of physiology, pathology and diagnosis.