A novel Au/r-GO/TNTs electrode for H2O2, O2 and nitrite detection

Au nanoparticles and reduced graphene oxide (r-GO) co-modified TiO 2 nanotube arrays (TNTs) were prepared by a facile and green strategy based on the electro-deposition technology for detecting H 2 O 2 , O 2 and nitrite. As-prepared Au/r-GO/TNTs electrode was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results clearly demonstrate that the successful attachment of r-GO sheets and narrow-range distribution of Au nanoparticles on TNTs . The reduced grapheme oxide sheet can help to improve the electronic conductive performance of TNTs and prevent the agglomeration of Au nanoparticles. Electrochemical studies reveal that the Au/r-GO/TNTs electrode exhibit excellent electrocatalytic performance toward the reduction of H 2 O 2 . Under the optimal experimental condition, the sensor has a quick response to H 2 O 2 at −0.3   V with a high sensitivity (1011.35   mA   M −1   cm −2 ), wide linear range (0.01–22.3   mM) and low detection limit (0.006   μM). In addition, the sensor also has good stability and excellent selectivity. Moreover, the established Au/r-GO/TNTs electrode also shows high sensitivities towards dissolved O 2 and nitrite ions, which has great potential for the development of electrochemical sensors, molecular bioelectronics devices and biosensors.