Electrochemiluminescent biosensor with DNA link for selective detection of human IgG based on steric hindrance.

Abstract A highly selective DNA-based electrochemiluminescence (ECL) based biosensor is described for the detection of human IgG. It is exploiting the effect of steric hindrance that affects the strength of the ECL signal in the presence of IgG. Digoxin-linked signaling DNA was specifically bound to IgG, and this causes steric hindrance which limits the ability of DNA to hybridize with capturing DNA attached to a gold electrode. Europium (II) doped CdSe quantum dots were covalently linked to the DNA in order to generate the ECL signal. Using this steric hindrance hybridization method, the ECL signal of the biosensor were proportional to the concentration of IgG with a wide linear range and a 14 pM detection limit. Conceivably, the method can be expanded to the detection of a wide range of proteins for which homologous recognition elements are available. Graphical abstract In the manuscript, a highly sensitive DNA-based electrochemiluminescence (ECL) biosensor was developed for the detection of human IgG (IgG), which takes advantage of steric hindrance effects to influence the ECL signal in the presence of target protein. The prepared ECL biosensor presented higher sensitivity and could be applied in other proteins with homologous recognition elements. fx1 Highlights • A highly selective DNA-based electrochemiluminescence (ECL) based biosensor is described for the detection of human IgG. • The biosensor takes advantage of steric hindrance effects to influence ECL signal in the presence of IgG. • This method could achieved good results in the analysis of real samples. [ABSTRACT FROM AUTHOR]