title: A label-free and time-resolved luminescence strategy for the detection of proteins based on DNA-Tb(3+) luminescence quenched by graphene oxide.
abstract: A sensitive, label-free and time-resolved luminescent aptasensor to detect proteins was developed based on the DNA-enhanced time-resolved luminescence of Tb(3+) and graphene oxide (GO). We found that the DNA no matter with a G-quadruplex structure or not could greatly enhance the long-lived emission of Tb(3+), and the luminescence of DNA-Tb(3+) could be effectively quenched by GO after the DNA-Tb(3+) was adsorbed onto GO. The target protein combined with an aptamer to form a protein/DNA complex restrained the quenching of DNA-Tb(3+) emission by GO. Thrombin and a 29-mer anti-thrombin aptamer were employed as a model analyte and a recognition element. There is a good linear relationship between the aptamer-Tb(3+) complex luminescence with the thrombin concentrations of 1 to 100 nM with a low detection limit of 0.8 nM. Since the time-resolved luminescence can eliminate the unspecific background fluorescence, the proposed aptasensor has been successfully applied in complicated biological samples for thrombin detection. This novel strategy presents a potential universal method for detection of other molecules.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China. wli@hnu.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Wang
authors.initials: W
authors.lastname: Li
authors.forename: Zhou
authors.initials: Z
authors.lastname: Nie
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D000327:Adsorption; D052157:Aptamers, Nucleotide / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D054856:G-Quadruplexes; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D008958:Models, Molecular; D010087:Oxides / Q000737:chemistry*; D013725:Terbium / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors
chemical_list: D052157:Aptamers, Nucleotide; D010087:Oxides; D013725:Terbium; D006108:Graphite; D004247:DNA; D013917:Thrombin