Ag nanoparticles embedded in N-doped carbon nanofibers: A superior electrocatalyst for hydrogen peroxide detection

Abstract

Improving the sensitivity and stability of Ag nanoparticles-based sensors is crucial for non-enzymatic H2O2 detection. Herein, Ag nanoparticles embedded N-doped carbon nanofibers (Ag/NCNFs) were prepared by electrospinning and subsequent thermal treatment. Characterization results showed that Ag nanoparticles with uniform size were homogeneously embedded in NCNFs porous matrix. Such an embedded structure could well prevent the aggregation of Ag nanoparticles and improve their electrocatalytic ability and stability. The preliminary test results of electrocatalytic activity suggested that Ag/NCNFs displayed obvious characteristic of electrocatalysis for H2O2 reduction. In amperometric experiments, Ag/NCNFs-based sensors exhibited excellent H2O2 analytical performances of wide linear range (0.02–20 mM), low detection limit (0.15 μM), high sensitivity (142.2 μA mM−1 cm−2), high selectivity and anti-interference. In addition, the Ag/NCNFs-based sensor had superior reproducibility and excellent stability and the Ag/NCNFs-GCE could maintain 98.4% of the initial current response after storing it at 25 °C for 15 days. More significantly, the as-fabricated sensor could be further used to detect the concentrations of H2O2 in milk samples and displayed satisfactory recoveries and relative standard deviation (RSD). These results manifested that Ag/NCNFs had potential to be utilized as a promising material for constructing non-enzymatic H2O2 sensors.