title: Simultaneous and sensitive detection of dual DNA targets via quantum dot-assembled amplification labels.
abstract: We describe a signal amplification assay for the simultaneous detection of HIV-1 and HIV-2 via a quantum dot (QD) layer-by-layer assembled polystyrene microsphere (PS) composite in a homogeneous format. The crucial point of this composite is the core-shell system. PS is utilized as the core and QDs as the shell. Based on the high affinity of streptavidin and biotin, QDs are assembled layer-by-layer on the surface of the PS as amplification labels. Biotinylated reporter probe is combined with the PS-QDs conjugate and then hybridized with target DNA immobilized on the surface of a 96-well plate. Using this approach, each target DNA corresponds to a large number of QDs and the fluorescence signal is greatly enhanced. Two QD colors (605 and 655 nm) are used to detect dual-target DNAs simultaneously. Taking advantage of the enzyme-free reaction and high sensitivity, this PS-QD-based sensor can be used in simple 'mix and detection' assays. Our results show that this technology has potential application in rapid point-of-care testing, gene expression studies, high-throughput screening and clinical diagnostics.
authors.affiliation: School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, Fudan University, Shanghai, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Cui
authors.affiliation: School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, Fudan University, Shanghai, China.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Song
authors.affiliation: School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, Fudan University, Shanghai, China.
authors.forename: Zhijuan
authors.initials: Z
authors.lastname: Cao
authors.affiliation: School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, Fudan University, Shanghai, China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Lu
mesh_terms: D004279:DNA, Viral / Q000032:analysis*; D015497:HIV-1 / Q000737:chemistry / Q000302:isolation & purification*; D015498:HIV-2 / Q000737:chemistry / Q000302:isolation & purification*; D008863:Microspheres; D011137:Polystyrenes / Q000737:chemistry; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence
chemical_list: D004279:DNA, Viral; D011137:Polystyrenes
keywords: dual DNA targets; layer-by-layer; polystyrene microsphere; quantum dots