title: Electrochemical detection of protein based on hybridization chain reaction-assisted formation of copper nanoparticles.
abstract: In this paper, we report an electrochemical method for highly sensitive and specific detection of protein based on hybridization chain reaction (HCR)-assisted formation of copper nanoparticles by using small molecule such as folate-linked DNA as probe. In the presence of target protein, taking folate receptor (FR) as the model protein in this study, its binding with folate can protect the probe DNA from exonuclease I-catalyzed degradation, thus the probe DNA can be immobilized onto the electrode surface through the hybridization with capture DNA, triggering HCR on the electrode surface. Subsequently, copper nanoparticles can be formed on the electrode surface by using long duplex DNA oligomers from HCR as templates. Furthermore, copper ions released from acid-dissolution of copper nanoparticles can catalyze the oxidation of ο-phenylenediamine by dissolved oxygen, leading to significant electrochemical responses. As a result, our method can sensitively detect FR in the linear range from 0.01ng/mL to 100ng/mL with a detection limit of 3pg/mL. It can also specifically distinguish the target protein in both buffer and complex serum samples. Since many other proteins can be assayed by changing the corresponding small molecule, this method may be promising for the development of the technique for protein detections.
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Suisui
authors.initials: S
authors.lastname: Hu
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China; State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, Nanjing University, Nanjing 210093, PR China. Electronic address: genxili@nju.edu.cn.
authors.forename: Genxi
authors.initials: G
authors.lastname: Li
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D003300:Copper / Q000737:chemistry*; D015342:DNA Probes / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D058973:Folate Receptors, GPI-Anchored / Q000032:analysis / Q000097:blood*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods
chemical_list: D015342:DNA Probes; D058973:Folate Receptors, GPI-Anchored; D003300:Copper
keywords: Copper nanoparticles; Electrochemical techniques; Hybridization chain reaction; Signal amplification; Terminal protection