Single-step turn-on homogeneous fluorescent immunosensor for rapid, sensitive, and selective detection of proteins

Abstract

Quick & easy: A simple and positive-readout fluorescent immunosensor was developed based on a quencher composed of a 3 nm gold nanoparticle (GNP) covalently linked to a Fab fragment, which proved to be stable and specific. The method allows for direct and sensitive detection of target antigens in homogeneous solutions in one step without any separation steps. It has been successfully applied to rapidly quantify the amount of secretory immunoglobulin A (sIgA) in human saliva samples.