3D bioprinting biomimetic small intestinal microtissue-based molecularly imprinted electrochemical sensor for sensitive detection of ovalbumin

This study presents a novel sensing strategy for ovalbumin (OVA) by integrating a controllable molecularly imprinted polymer (MIP) fabrication technique with three-dimensional (3D) bioprinting technology. A MIP with high specificity and affinity was designed and synthesized for OVA using the reverse microemulsion epitope-directed surface imprinting and coating (ROSIC) method with silylating monomers. The synthesized MIP was then innovatively incorporated into gelatin methacryloyl (GelMA) and uesd as bioink to 3D bioprint a biomimetic small intestinal microtissue, which was subsequently assembled into a working electrode. Together with a homemade Ag/AgCl reference electrode and a platinum wire counter electrode, the resulting interface formed a three-electrode electrochemical sensing system for OVA detection. The constructed sensor exhibited a linear response to OVA concentration in the range of 10–400 pg/mL. The standard curve equation was R et  = 11.12 C OVA (pg/mL)  + 3261.9, with a correlation coefficient R 2 of 0.998, and a detection limit of 5.54 pg/mL.