title: Rolling cycle amplification based single-color quantum dots-ruthenium complex assembling dyads for homogeneous and highly selective detection of DNA.
abstract: In this work, a new, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots-ruthenium complex (QDs-Ru) assembling dyads. This strategy includes three steps: (1) the target DNA initiates RCA reaction and generates linear RCA products; (2) the complementary DNA hybridizes with the RCA products to form long double-strand DNA (dsDNA); (3) [Ru(phen)2(dppx)](2+) (dppx=7,8-dimethyldipyrido [3,2-a:2',3'-c] phenanthroline) intercalates into the long dsDNA with strong fluorescence emission. Due to its strong binding propensity with the long dsDNA, [Ru(phen)2(dppx)](2+) is removed from the surface of the QDs, resulting in restoring the fluorescence of the QDs, which has been quenched by [Ru(phen)2(dppx)](2+) through a photoinduced electron transfer process and is overlaid with the fluorescence of dsDNA bonded Ru(II) polypyridyl complex (Ru-dsDNA). Thus, high fluorescence intensity is observed, and is related to the concentration of target. This sensor exhibits not only high sensitivity for hepatitis B virus (HBV) ssDNA with a low detection limit (0.5 pM), but also excellent selectivity in the complex matrix. Moreover, this strategy applies QDs-Ru assembling dyads to the detection of single-strand DNA (ssDNA) without any functionalization and separation techniques.
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: Chen
authors.initials: C
authors.lastname: Su
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: Tai
authors.initials: T
authors.lastname: Ye
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: 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: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D003116:Color; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D004279:DNA, Viral / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D006515:Hepatitis B virus; D057230:Limit of Detection; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D009942:Organometallic Compounds / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D004279:DNA, Viral; D009942:Organometallic Compounds; D012428:Ruthenium; D004247:DNA
keywords: DNA detection; Quantum dots; Rolling circle amplification; Ruthenium complex; Signal amplification