Development of a molecular imprinted electrochemical sensor for point-of-care determination of lysine in blood

The accurate quantification of lysine is crucial for animal health and nutrition. In this work, we report the development of a novel electrochemical sensor for rapid, highly selective, and pretreatment-free quantification of lysine in whole blood. The sensor was fabricated by electrodepositing Prussian blue on screen-printed carbon electrodes, followed by electropolymerization of a lysine-imprinted polymer layer. We implemented a computational design strategy, integrating molecular docking and density functional theory calculations, to screen and identify the optimal functional monomer with high lysine binding affinity. The developed sensor exhibited a linear response to lysine concentration in simulated serum, with a limit of detection of 28.1 μM. It demonstrated high selectivity against structural analogs and common blood interferents. Validation using swine serum samples showed excellent agreement with results obtained from an amino acid analyzer. Furthermore, the sensor successfully quantified lysine in whole blood samples without any pretreatment, providing a simple, reliable, and efficient platform for on-site lysine detection in resource-limited settings.