Ultrasensitive electrochemical sensor based on molecular imprinted polymer and ferromagnetic nanocomposite for bilirubin analysis in the saliva and serum of newborns

• Excessive amounts of bilirubin can cause severe and irreversible damage to the brain and nerves system, especially in infants. • A new MIP-based electrochemical sensor was used to detect neonatal jaundice in saliva and serum samples. • A monomer 4-ATP was used for electropolymerization and MIP electrode fabrication. • The electrochemical behavior of the sensor was evaluated by DPV, CV, and EIS techniques. • LOD values were calculated to be 1.54 and 1.36 p M , and LOQ values were calculated to be 5.14 and 5.3 p M . A new Molecularly Imprinted Polymer (MIP)-based electrochemical sensor was used to detect neonatal jaundice in saliva and serum samples. The Bilirubin (BR) detection sensor is fabricated by 2-aminothiophenol (2-ATP) polymerization on MIP/AuFe 2 O 3 -GrCNT/GCE using a Glassy Carbon Electrode (GCE). BR is an important factor in the body. Excessive amounts of BR can cause severe and irreversible damage to the brain and nerves, especially in infants. Engraving detection sites created by washing patterns from engraved polymer make it possible to detect the target analyte by creating three-dimensional holes. The electrochemical behavior of the sensor was evaluated by Differential Pulse Voltammetry (DPV), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS) techniques in 10.0 mM of [Fe(CN) 6 ] −3/−4 solution with 0.1 M of KCl. Surface analysis was performed by Scanning Electron Microscopy (SEM) and the accuracy of the research measurement was checked by High Pressure Liquid Chromatography (HPLC). After creating optimal conditions in two domains, two wide linear responses from 3.7 to 13.2 nM and 3.7 to 13.0 pM were obtained. Limit of Detection (LOD) values were calculated to be 1.54 nM and 1.36 pM, and Limit of Quantitation (LOQ) values were calculated to be 5.14 nM and 5.3 pM. Owing to rapid detection ability, cost-effectiveness, low sample consumption, high sensitivity, extremely low interference, and good stability, this sensor can be a promising tool to detect the cause of neonatal jaundice in the saliva and serum of the infants.