An Optimized Bioassay for Mucin1 Detection in Serum Samples

Two simple and sensitive electrochemical approaches for Mucin1 (MUC1) tumor marker using magnetic beads coupling screen-printed arrays were developed. The single-use bioassays are based on a sandwich format in which aptamers or antibodies were coupled respectively to Streptavidin or Protein G-modified magnetic beads. The bioreceptor-modified beads are used to capture the MUC1 protein from the sample and sandwich assay is performed by the addition of a labeled secondary aptamer or antibody. The enzyme alkaline phosphatase and its substrate (1-naphthyl phosphate) are then used for the electrochemical detection by differential pulse voltammetry (DPV). The analytical performances of the designed bioassays were compared in terms of sensitivity, selectivity and reproducibility. Using the optimized conditions, a linear range from 0 to 0.28 nM was obtained, with 0.19 nM LOD using antibody-based and 0.07 nM LOD using aptamer-based sandwich assay in MUC1 buffered solutions. The results also showed that the aptamer-based approach exhibited higher selectivity for MUC1, allowing the detection of the protein in complex matrices. The developed aptasensor for MUC1 detection was applied on serum samples obtained from cancer patients, providing promising perspectives for clinical applications.