title: A recognition-before-labeling strategy for sensitive detection of lung cancer cells with a quantum dot-aptamer complex.
abstract: A highly specific recognition-before-labeling strategy has been developed for sensitive detection of non-small cell lung cancer A549 cells, by using fluorescent QDs as signal units and DNA aptamers as recognition elements. A QD-aptamer system used for cell imaging and bioanalysis mostly relies on the recognition-after-labeling strategy in which aptamers were firstly labeled with QDs and then the QD-aptamer conjugates as a whole were utilized for specific recognition. Here in our strategy, aptamers were used firstly to recognize target cells, and then fluorescent QDs were sequentially added to bind the aptamers and light the target cells. The proposed recognition-before-labeling strategy didn't require the complex process of QD functionalization, and avoided the possible impact on the aptamer configuration from steric hindrance. Meanwhile, QDs, with strong fluorescence and good photostability, also give this method a high signal-to-background ratio (S/B). The recognition-before-labeling strategy is simple and sensitive, suggesting a new method for in vitro diagnostic assays of cancer cells.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry & Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China. kmwang@hnu.edu.cn yangxiaohai@hnu.edu.cn.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wu
authors.forename: Jianbo
authors.initials: J
authors.lastname: Liu
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Haining
authors.initials: H
authors.lastname: Ji
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Yang
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism; D001710:Biotin / Q000737:chemistry / Q000378:metabolism; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D008856:Microscopy, Fluorescence; D045663:Quantum Dots / Q000737:chemistry*; D059629:Signal-To-Noise Ratio
chemical_list: D052157:Aptamers, Nucleotide; D001710:Biotin; D016650:Fluorescein-5-isothiocyanate