Photoelectrochemical bilirubin biosensor based on Fe3O4/hydroxyapatite/molecularly imprinted polypyrrole nanoparticles

Magnetic Fe 3 O 4 /hydroxyapatite/molecularly imprinted polypyrrole (Fe 3 O 4 /HAP/MIPPy) nanoparticles with molecularly recognitive photoactivity were successfully prepared via the surface modification and molecular imprinting technique. A novel photoelectrochemical bilirubin biosensor was fabricated by conveniently attaching the proposed Fe 3 O 4 /HAP/MIPPy nanoparticles to the surface of the magnetic glassy carbon electrode (MGCE). The developed biosensor was highly sensitive to bilirubin in solutions, with a linear range from 0.1 to 17   μM and a limit of detection of 0.007   μM. Moreover, the biosensor exhibited outstanding selectivity while used in coexisting systems containing various interferents with high concentration. The favorable performance of the obtained bilirubin biosensor can be mainly attributed to high photoelectric activity, large surface-to-volume ratio, fast electron transfer and selective recognition of Fe 3 O 4 /HAP/MIPPy nanoparticles . The analytical application of the photoelectrochemical bilirubin biosensor confirms the feasibility of bilirubin detection in serum sample.