Durand Alegría, Jesús SenénPaniagua González, GemaFernández Hernando, Pilar2024-05-202024-05-202009-01-091618-2642 - eISSN 1618-2650https://doi.org/10.1007/s00216-008-2584-9https://hdl.handle.net/20.500.14468/11609This work reports a comparative study of two automated flow-through fluorosensors for the determination of digoxin in serum samples: an immunosensor with an anti-digoxin polyclonal antibody as the reactive phase permanently immobilized on CPG, and a sensor with a selective reaction system based on a methacrylic molecularly imprinted polymer (MIP) synthesized by bulk polymerisation. The variables affecting the sensitivity and dynamic range of the sensors (e.g., the carrier and elution solutions, flow-rates, pH and reagent concentrations) were optimised and the binding characteristics of their reactive phases compared in a competitive fluorescent assay. Digoxin was reproducibly determined by both sensors at the mg L-1 level (detection limit= 1.20×10-3 mg L-1 and RSD= 4-7% for the immunosensor; detection limit= 1.7×10-5 mg L-1 and RSD= 1-2% for the MIP sensor). No cross reactivity with digoxinrelated compounds was seen for either sensor at a digoxin:interferent ratio of 1:100. The lifetime of the immunosensor was about 50 immunoassays; its shelf life, when unused, is about three months. The lifetime of the MIP sensor was over 18 months. Both sensors were used to determine the digoxin concentration of human serum samples with satisfactory results.eninfo:eu-repo/semantics/openAccessjournal articleDigoxinPermanent immobilizationMolecular imprintingFlow-through fluorosensorSerum analysis