title: DNA-conjugated quantum dot nanoprobe for high-sensitivity fluorescent detection of DNA and micro-RNA.
abstract: Herein, we report a convenient approach to developing quantum dots (QDs)-based nanosensors for DNA and micro-RNA (miRNA) detection. The DNA-QDs conjugate was prepared by a ligand-exchange method. Thiol-labeled ssDNA is directly attached to the QD surface, leading to highly water-dispersible nanoconjugates. The DNA-QDs conjugate has the advantages of the excellent optical properties of QDs and well-controlled recognition properties of DNA and can be used as a nanoprobe to construct a nanosensor for nucleic acid detection. With the addition of a target nucleic acid sequence, the fluorescence intensity of QDs was quenched by an organic quencher (BHQ2) via Förster resonance energy transfer. This nanosensor can detect as low as 1 fM DNA and 10 fM miRNA. Moreover, the QDs-based nanosensor exhibited excellent selectivity. It not only can effectively distinguish single-base-mismatched and random nucleic sequences but also can recognize pre-miRNA and mature miRNA. Therefore, the nanosensor has high application potential for disease diagnosis and biological analysis.
authors.affiliation: Key Laboratory for Organic Electronics & Information Displays (KLOEID), Institute of Advanced Materials (IAM), and School of Materials Science and Engineering, Nanjing University of Posts & Telecommunications , 9 Wenyuan Road, Nanjing 210046, China.
authors.forename: Shao
authors.initials: S
authors.lastname: Su
authors.forename: Jinwei
authors.initials: J
authors.lastname: Fan
authors.forename: Bing
authors.initials: B
authors.lastname: Xue
authors.forename: Lihui
authors.initials: L
authors.lastname: Yuwen
authors.forename: Xingfen
authors.initials: X
authors.lastname: Liu
authors.forename: Dun
authors.initials: D
authors.lastname: Pan
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
authors.forename: Lianhui
authors.initials: L
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D035683:MicroRNAs / Q000737:chemistry / Q000302:isolation & purification*; D045663:Quantum Dots / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D035683:MicroRNAs; D014867:Water; D004247:DNA