Enhanced Electrochemiluminescence Detection for Hydrogen Peroxide Using Peroxidase-Mimetic Fe/N-Doped Porous Carbon

Detecting hydrogen peroxide (H2O2) is obviously indispensable on account of its low toxicity and wide application, and it is still a challenge for developing highly sensitive and selective electrochemiluminescence (ECL) sensors based on the noble metal-free electrode. Hence, we designed an accurate ECL sensor for detecting trace H2O2 based on N-doped porous carbon containing Fe (Fe/N-C) nanocomposites, which were successfully synthesized by pyrolysis of NH2-MIL-101(Fe) metal-organic framework (MOF). Fe/N-C nanocomposite significantly improved the electron transfer process and enhanced the catalytic activity of ECL sensor for trace H2O2 detection. Fe/N-C nanocomposite significantly contributed in the conversion of H2O2 to superoxide radical, followed by the oxidation of luminal which enhanced the electrochemical luminescence signal. Predictably, the ECL sensing strategy at Fe/N-C nanocomposite electrode showed a satisfying linear range from 1 nM to 300 nM for H2O2 detection with limit of detection (LOD) as 0.93 nM (signal to noise ratio (S/N) = 3). Also, the ECL sensor was used to detect H2O2 in real water samples and renal epithelial 293T cells, which justified great promise for the practical ECL detection of H2O2. (C) 2019 The Electrochemical Society.