Digitizing immunoassay on an antibody nanoarray to improve assay sensitivity

Immunoassays are routine tests used to quantify proteins in biological samples, such as blood or serum. An important challenge to early diagnosis of diseases is the detection of biomarkers at ultra-low concentration, which requires ultra sensitivity assays. Here, we using a novel lift-off nanocontact printing technique to produce a large-scale antibody nanoarray (ANA), and use this array to perform sandwich assays. The sandwich format ensures the high specificity and the nanoarray (NA) allows us to digitize the assay results by counting the binding events discretely. We show that the digitization of immunoassays improves assay sensitivity.