A novel electrochemical sensor based on Fe2O3 nanoparticles/N-doped graphene for electrocatalytic oxidation of L-cysteine

A novel electrochemical sensor based on Fe 2 O 3 nanoparticles supported on N-doped graphene (Fe 2 O 3 NPs/N–GR) has been fabricated for electrocatalytic oxidation and detection of L-cysteine. The Fe 2 O 3 NPs/N–GR was characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The electrochemical behavior of L-cysteine at Fe 2 O 3 NPs/N–GR was investigated by voltammetry. The Fe 2 O 3 NPs/N–GR showed a very efficient electrocatalytic activity for the oxidation of L-cysteine in 0.1 M phosphate buffer solution (PBS, pH 7.0). The oxidation peak currents increased dramatically at Fe 2 O 3 NPs/N–GR-modified electrode. The potential utility of the sensor was demonstrated by applying it to the analytical determination of L-cysteine. Experimental results showed that the electrocatalytic current increased linearly with L-cysteine concentration in the range of 0.2–400 μM with a lowest detectable concentration of 0.1 μM.