Binding-induced DNA assembly makes Exo III-aided signal amplification universal for highly sensitive protein detection

Abstract

Exonuclease III has been involved in many signal amplification strategies for bioanalysis. Although Exo III-based signal amplification methods are sensitive and simple compared to other nuclease-based strategies, existing methods do not work for all proteins. In this work, we combine Exo III-aided signal amplification with binding-induced DNA assembly for highly sensitive protein detection. Two separate single-stranded DNA will hybridize after binding to the same target, and trigger the Exo III-aided target recycling amplification. This strategy can realize homogeneous detection of all proteins, and the detection conditions and performance were discussed. Human epididymis protein-4 (HE4) was token as example, a linear detection range of 0.01 ∼ 50 ng/mL, with the LOD of 3 pg/mL for rapid detection is presented. Notably, a linear relationship in range of 0.05 ∼ 1 pg/mL can be obtained with long time incubation. In conclusion, we believe that this novel approach will have significant implications in life science research, disease diagnosis, treatment, and prognosis.