Microarray of stimuli-responsive microbeads for duplexed immunoassay

This paper describes a duplexed immunoassay method based on a functional microbeads (μbeads) array. For selective detection of dual analytes, the μbeads were conjugated with a responsive biopolymer, characterized by a different phase transition temperature. Then, the μbeads modified with elastin-like polypeptides (ELPs) were spatially localized in a single microwell through sequential injection with a buffer. Prostate specific antigen (PSA) and mouse immunoglobulin G (IgG) were selected to show the feasibility of duplexed immunoassay. The detection limit of the μbead array with PSA and mouse IgG was 0.05 ng/mL and 0.1 ng/mL, respectively.