Fabrication of Red Mud/Molecularly Imprinted Polypyrrole-Modified Electrode for the Piezoelectric Sensing of Bilirubin

Red mud/molecularly imprinted polypyrrole (RM/MIPPy) microparticles were successfully prepared via the surface modification and molecular imprinting technique. A novel piezoelectric sensing platform with excellent molecular recognition capability was established for the detection of bilirubin (BR) based on the immobilization of the RM/MIPPy microparticles onto quartz crystal microbalance (QCM) electrode. The performance of the fabricated biosensor was evaluated and the results indicated that the biosensor exhibited high sensitivity in BR detection, with a linear range from 0.01 to 120 μM and a limit of detection of 0.003 μM. Moreover, the biosensor presented outstanding selectivity toward BR in comparison to other interferents. The analytical application of the BR biosensor confirmed the feasibility of BR detection in serum sample.