Chemiluminescent magnetic nanoparticles with good catalytic activity and rapid separation capability and sensitive sensing for H2O2

It is of considerable importance to develop chemiluminescent functionalized nanomaterials (CF-NMs) with good catalytic activity, high chemiluminescence (CL) efficiency and good stability, and rapid magnetic separation capability, achieving excellent performance in CL biosensing. In this study, N-(4-aminobutyl)-N-ethylisoluminol (ABEI)-functionalized CuFe2O4 magnetic nanomaterial (ABEI/CuFe2O4) with high catalytic activity was synthesized by virtue of a solvothermal and post-functionalization method. ABEI/CuFe2O4 showed outstanding CL properties, superior to ABEI-CuFe2O4 in liquid phase. This reveals that the immobilization of ABEI on the surface of CuFe2O4 exhibits unique heterogeneous catalytic property. The catalytic ability of CuFe2O4 was better than that of CoFe2O4, ZnFe2O4, MnFe2O4, and NiFe2O4. It is suggested that the peroxide-like activity as well as Cu2+ and Cu0 enriched on the surface of ABEI/CuFe2O4 opened up a dual route for synergistic catalysis of H2O2. ABEI/CuFe2O4 also demonstrated good superparamagnetism and magnetic separation could be carried out in 2 min, which is advantageous for the separation and purification of ABEI/CuFe2O4 during the synthetic procedures and bioassays. Owing to the sensitive response of ABEI/CuFe2O4 to H2O2, an enzyme-free sensor was developed for the detection of H2O2 with a wide linear range over 5 orders of magnitude of H2O2 concentrations and a low detection limit of 5.6 nM. The as-developed sensor is sensitive, stable, and convenient. This work provides a new family member of nanomaterials with good magnetism and CL activity as well as good stability. The developed ABEI/CuFe2O4 shows great prospects in biocatalysis, bioassays, biosensing, and bioimaging, etc.