title: Aptamer-initiated on-particle template-independent enzymatic polymerization (aptamer-OTEP) for electrochemical analysis of tumor biomarkers.
abstract: Herein, an aptamer-initiated on-particle template-independent enzymatic polymerization (aptamer-OTEP) strategy for electrochemical aptasensor (E-aptasensor) is developed for analysis of cancer biomarker carcino-embryonic antigen (CEA). A pair of DNA aptamers is employed which can be specifically bond with CEA simultaneously. One of the aptamer is thiolated at 3'-terminal and immobilized onto the gold electrode as a capture probe, while the other one has a thiol group at its 5'-terminal and is modified onto the gold nanoparticles surface to form a nanoprobe. In the present of target, the two aptamers can "sandwich" the target, thus the nanoprobe is attached to the electrode. Then terminal deoxynucleotidyl transferase (TdT) is employed to catalyze the incorporation of biotin labeled dNTPs into the 3'-OH terminals of the DNA aptamer on the nanoprobe. The as-generated long DNA oligo tentacles allow specific binding of numerous avidin modified horseradish peroxidase (Av-HRP), resulting in tens of thousands of HRP catalyzed reduction of hydrogen peroxide and sharply increasing electrochemical signals. Taking advantage of the enzyme based nucleic acid amplification and nanoprobe, this strategy is demonstrated to possess the outstanding amplification efficiency.
authors.affiliation: School of Environmental and Biological and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Pengjuan
authors.initials: P
authors.lastname: Wang
authors.affiliation: School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China. Electronic address: wanying@mail.njust.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wan
authors.affiliation: School of Environmental and Biological and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Shengyuan
authors.initials: S
authors.lastname: Deng
authors.affiliation: School of Environmental and Biological and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China. Electronic address: yshulin@mail.njust.edu.cn.
authors.forename: Shulin
authors.initials: S
authors.lastname: Yang
authors.affiliation: School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Su
authors.affiliation: Division of Physical Biology and Bioimaging Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
authors.affiliation: Chemistry Department, King Saud University, Riyadh, 11451, Saudi Arabia.
authors.forename: Ali
authors.initials: A
authors.lastname: Aldalbahi
authors.affiliation: Division of Physical Biology and Bioimaging Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China. Electronic address: zuoxiaolei@sinap.ac.cn.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zuo
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D014408:Biomarkers, Tumor / Q000097:blood; D015374:Biosensing Techniques / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D004253:DNA Nucleotidylexotransferase / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D058105:Polymerization
chemical_list: D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D015342:DNA Probes; D006046:Gold; D004253:DNA Nucleotidylexotransferase
keywords: Aptamer-initiated on-particle template-independent enzymatic polymerization (aptamer-OTEP); Electrochemical aptasensor; Nanoprobe; Terminal deoxynucleotidyl transferase (TdT)