title: Dual-color determination of protein via terminal protection of small-molecule-linked DNA and the enzymolysis of exonuclease III.
abstract: We have developed a new dual-color fluorescent biosensor for protein detection based on terminal protection of small-molecule-linked DNA and the enzymolysis of exonuclease III (Exo III). The determination of streptavidin (SA) was realized via fluorescence signals of the green color from quantum dots (QDs) and the red from [Ru(phen)2(dppx)](2+). In the absence of SA, biotin-DNA was degradated by the Exo III, thus making the [Ru(phen)2(dppx)](2+) employed as a fluorescence quencher to the QDs. With the addition of SA, dual-color response appeared because of the specific binding between SA and biotin so that the biotin-dsDNA was protected and combined with [Ru(phen)2(dppx)](2+), leading to the QDs recovery and the generating of [Ru(phen)2(dppx)](2+) fluorescence. This sensor exhibited high sensitivity with a low detection limit (2.11ng/mL) and firstly introduced dual-color QDs-ruthenium complex dyads to protein assay.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Chaohui
authors.initials: C
authors.lastname: Chen
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Xinghu
authors.initials: X
authors.lastname: Ji
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: zhkhe@whu.edu.cn.
authors.forename: Zhike
authors.initials: Z
authors.lastname: He
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002384:Catalysis; D003124:Colorimetry / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005090:Exodeoxyribonucleases / Q000737:chemistry*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000295:instrumentation*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
chemical_list: D004268:DNA-Binding Proteins; D004247:DNA; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III
keywords: Dual-color; Protein detection; QDs; Terminal protection of small-molecule-linked DNA; [Ru(phen)(2)(dppx)](2+)