Multifunctional magnetic Fe3O4/nitrogen-doped porous carbon nanocomposites for removal of dyes and sensing applications

In this work, a multifunctional magnetic Fe3O4/nitrogen doped-porous carbon nanocomposite (Fe3O4/N-PCNC) with remarkable magnetic, adsorption and catalytic properties was synthesized using naringin as carbon precursor. Characterization studies revealed that Fe3O4/N-PCNC exhibited a mesoporous structure with different functional groups and good magnetic properties. Its applications for the removal of organic dyes as well as the non-enzymatic colorimetric detection of hydrogen peroxide and glucose were investigated. The removal of the organic dyes from water showed that over 99.7% crystal violet and rhodamine B, and 100% thionine with concentrations of ca. 60 mg/L can be removed by Fe3O4/N-PCNC within 15 min. Recovery and recycling studies showed that, after 5 cycles, Fe3O4/N-PCNC, lost only around 2.94%, 3.97% and 3.36% of its initial ability to remove crystal violet, rhodamine B and thionine, respectively. Furthermore, Fe3O4/N-PCNC exhibited intrinsic peroxidase-mimic activity. Fe3O4/N-PCNC was used for colorimetric sensing of hydrogen peroxide and glucose with high sensitivity and low limits of detection of 0.1 mu M and 2.6 mu M respectively. The glucose sensor also shows high reproducibility, selectivity and was successfully applied to sense glucose in various drinks. This indicates the promising application potential of Fe3O4/N-PCNC in water treatment, quality analysis and medicine fields.