Bioreceptor multi-walled carbon nanotubes@Fe3O4@SiO2–surface molecular imprinted polymer in an ultrasensitive chemiluminescent biosensor for bovine hemoglobin

An ultrasensitive chemiluminescent biosensor with a high selectivity, based on a bioreceptor surface molecular imprinted polymer (SMIP) that used core–shell Fe3O4@SiO2–multi-walled carbon nanotube nanostructures (Fe3O4@SiO2/MWCNTs) as the backbone material, for bovine hemoglobin (BHb) determination was proposed. The Fe3O4@SiO2/MWCNTs were synthesized with a new method, and then were characterized using SEM, FTIR and XRD techniques. The adsorption ability of Fe3O4@SiO2/MWCNTs–SMIP was evaluated to be 91 mg g−1 following the Langmuir isotherm equation and it demonstrated an excellent recognition and adsorption ability for the imprinted sites located on the surface or near the surface of the Fe3O4@SiO2/MWCNTs. Under optimum conditions of CL, the detection range of BHb was from 5.0 × 10−10 to 7.0 × 10−7 mg mL−1 with a detection limit of 1.5 × 10−10 mg mL−1 (3δ). The proposed biosensor was successfully applied in the determination of BHb in real samples with high selectivity and sensitivity, and the recoveries were excellent and varied from 92% to 106%. Finally, the possible CL mechanism of the BHb in amplifying the CL signal of the luminol–NaOH–H2O2 system was discussed.