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.