title: Label-free and homogeneous aptamer proximity binding assay for fluorescent detection of protein biomarkers in human serum.
abstract: By using the aptamer proximity binding assay strategy, the development of a label-free and homogeneous approach for fluorescent detection of human platelet-derived growth factor BB (PDGF-BB) is described. Two G-quadruplex forming sequence-linked aptamers bind to the PDGF-BB proteins, which leads to the increase in local concentration of the aptamers and promotes the formation of the G-quadruplex structures. Subsequently, the fluorescent dye, N-methylmesoporphyrin IX, binds to these G-quadruplex structures and generates enhanced fluorescence emission signal for sensitive detection of PDGF-BB. The association of the aptamers to the PDGF-BB proteins is characterized by using native polyacrylamide gel electrophoresis. The experimental conditions are optimized to reach an estimated detection limit of 3.2nM for PDGF-BB. The developed method is also selective and can be applied for monitoring PDGF-BB in human serum samples. With the advantages of label-free and homogeneous detection, the demonstrated approach can be potentially employed to detect other biomarkers in a relatively simple way.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Biomedical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yunatswu@swu.edu.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D052157:Aptamers, Nucleotide / Q000378:metabolism*; D001483:Base Sequence; D000077214:Becaplermin; D015415:Biomarkers / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods*; D001798:Blood Proteins / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005456:Fluorescent Dyes / Q000378:metabolism; D054856:G-Quadruplexes; D006801:Humans; D057230:Limit of Detection; D008652:Mesoporphyrins / Q000378:metabolism; D008969:Molecular Sequence Data; D020574:Proto-Oncogene Proteins c-sis / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D052157:Aptamers, Nucleotide; D015415:Biomarkers; D001798:Blood Proteins; D005456:Fluorescent Dyes; D008652:Mesoporphyrins; D020574:Proto-Oncogene Proteins c-sis; C065420:N-methylmesoporphyrin IX; D000077214:Becaplermin
keywords: Aptamer; Fluorescent detection; Human platelet-derived growth factor; Label-free; Proximity binding