Synthesis and size-dependent electrochemical nonenzymatic H2O2 sensing of cuprous oxide nanocubes

Abstract

In this work, we reported an electrochemical approach for the nonenzymatic detection of H₂O₂ based on a cuprous oxide (Cu₂O) nanocube-based sensor. The Cu₂O nanocubes were synthesized with controllable sizes from 40 nm to 360 nm through a facile additive-free aqueous solution route at room temperature. The electrocatalytic activities of the Cu₂O nanocubes with five different sizes towards H₂O₂ were systematically explored, and it was found that the electrocatalytic activity was strongly dependent on the size of the Cu₂O nanocubes. The cyclic voltammetry and amperometry results show that these Cu₂O nanocubes exhibited good electrocatalytic activity with a linear response ranging from 0.5 to 8.5 mM at −0.2 V and a detection limit of 1.61 μM (S/N = 3). Furthermore, the Cu₂O nanocubes of five different sizes have good selectivity for H₂O₂ detection with ascorbic acid (AA), uric acid (UA) and glucose (Glu).