title: Electrochemical immunosensor of platelet-derived growth factor with aptamer-primed polymerase amplification.
abstract: A new method for the determination of platelet-derived growth factor BB (PDGF-BB) was developed using an electrochemical immunosensor with an aptamer-primed, long-strand circular detection probe. Rabbit anti-human PDGF-B polyclonal antibody was immobilized on the electrode to serve as the capture antibody. The detection probe was synthesized via polymerase extension along a single-stranded circular plasmid DNA template with a primer headed by the anti-PDGF-B aptamer. In the presence of the analyte, the aptamer-primed circular probe was captured on the electrode via the formation of an antibody/PDGF-BB/aptamer sandwiched complex. The electroactivity indicator methylene blue was adsorbed on the electrode surface via the analyte-sandwiched complex with long-strand circular DNA, thus yielding a strong electrochemical signal for the quantification of PDGF-BB. This strategy allowed electrochemical detection with enormous signal amplification arising from the long-strand localized circular probe. The oxidation peak current of methylene blue in square wave voltammetric measurements showed a linear dependence on the concentration of PDGF-BB in the range from 50 to 500 ng mL(-1), with a detection limit as low as 18 pg mL(-1).
authors.affiliation: State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Nie
authors.forename: Shao-Long
authors.initials: SL
authors.lastname: Gan
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000378:metabolism; D052157:Aptamers, Nucleotide / Q000378:metabolism*; D000077214:Becaplermin; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D004270:DNA, Circular / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D017097:Electric Impedance; D004563:Electrochemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008751:Methylene Blue / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000032:analysis* / Q000276:immunology; D020574:Proto-Oncogene Proteins c-sis; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D052157:Aptamers, Nucleotide; D004270:DNA, Circular; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D004259:DNA-Directed DNA Polymerase; D008751:Methylene Blue