Synthesis of FeOOH@PDA-Ag nanocomposites and their application for electrochemical sensing of hydrogen peroxide

A well-dispersed Ag nanoparticle (Ag NP) anchored on rod-like Ferric oxyhydroxide@polydopamine (FeOOH@PDA) electrocatalyst was achieved via in situ reduction at room temperature. The obtained FeOOH@PDA-Ag nanocomposites were used for fabricating a novel non-enzymatic H2O2 sensor. The relationship between the sensing interface material and the sensor performance was studied, and a new method for the detection of H2O2 was established. The composition and morphology of the nanocomposites were characterized by transmission electron microscopic (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS), which indicated that large numbers of Ag NPs with a narrow size were uniformly distributed on the surface of FeOOH@PDA. The electrochemical investigation showed that the nanocomposites had excellent electrocatalytic property toward the reduction of H2O2, and the sensor displayed a linear response to H2O2 in the range of 7.5 μM-18.8 mM with a detection limit of 2.5 μM at a signal-to-noise ratio of 3 and a sensitivity of 11.8 μA mM− 1 cm− 2. Compared with other non-enzymatic H2O2 sensors, the linear range of this sensor improved one order of magnitude. Moreover, the good analytical performance, low cost and facile preparation method made this novel material a promising candidate for the development of effective non-enzymatic H2O2 sensor.