title: Proximity hybridization regulated DNA biogate for sensitive electrochemical immunoassay.
abstract: An electrochemical DNA biogate was designed for highly sensitive homogeneous electrochemical immunoassay by combining target-induced proximity hybridization with a mesoporous silica nanoprobe (MSN). The electroactive methylene blue (MB) was sealed in the inner pores of MSN with single-stranded DNA. In the presence of target protein and two DNA-labeled antibodies, the formed proximate complex could hybridize with the DNA strand to form a rigid double-stranded structure and thus open the biogate, which led to the release of MB entrapped in the MSN. The target protein-dependent amount of released MB could be conveniently monitored with a screen-printed carbon electrode. Moreover, the detachment process of MB could be further amplified with an in situ enzymatic recycling binding of the proximate complex with the single-stranded DNA. Using prostate-specific antigen as a model target, the proposed assay showed a wide detection range from 0.002 to 100 ng mL(-1) with a detection limit of 1.3 pg mL(-1). This strategy was simple and universal for various analytes with different affinity ligands. This method possessed great potential for convenient point-of-care testing and commercial application.
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China.
authors: Kewei
authors: K
authors: Ren
authors: Jie
authors: J
authors: Wu
authors: Yue
authors: Y
authors: Zhang
authors: Feng
authors: F
authors: Yan
authors: Huangxian
authors: H
authors: Ju
mesh_terms: D004247:DNA / Q000737:chemistry*; D017931:DNA Primers; D055664:Electrochemical Techniques / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization
chemical_list: D017931:DNA Primers; D004247:DNA