Fe₃O₄ nanoparticles entrapped in the inner surfaces of N-doped carbon microtubes with enhanced biomimetic activity

Abstract

Tubular structured composites have attracted great interest in catalysis research owing to their void-confinement effects. In this work, we synthesized a pair of hollow N-doped carbon microtubes (NCMTs) with Fe₃O₄ nanoparticles (NPs) encapsulated inside NCMTs (Fe₃O₄@NCMTs) and supported outside NCMTs (NCMTs@Fe₃O₄) while keeping other structural features the same. The impact of structural effects on the catalytic activities was investigated by comparing a pair of hollow-structured nanocomposites. It was found that the Fe₃O₄@NCMTs possessed a higher peroxidase-like activity when compared with NCMTs@Fe₃O₄, demonstrating structural superiority of Fe₃O₄@NCMTs. Based on the excellent peroxidase-like catalytic activity and stability of Fe₃O₄@NCMTs, an ultra-sensitive colorimetric method was developed for the detection of H₂O₂ and GSH with detection limits of 0.15 μM and 0.49 μM, respectively, which has potential application value in biological sciences and biotechnology.