title: Direct molecular detection of nucleic acids by fluorescence signal amplification.
abstract: An integrated PCR-free DNA sensor, which combines a sequence-specific receptor, an optical polymeric transducer, and an intrinsic fluorescence amplification mechanism, is reported. This sensor is based on the different conformations adopted by a cationic polythiophene when electrostatically bound to ss-DNA or ds-DNA, and on the efficient and fast energy transfer between the resulting fluorescent polythiophene/ds-DNA complex and neighboring fluorophores attached to ss-DNA probes. This molecular system allows the detection of only five molecules in 3 mL of an aqueous solution, or 3 zM, in 5 min. Moreover, this work demonstrates, for the first time, the direct detection of single nucleotide polymorphisms (SNPs) from clinical samples in only a few minutes, without the need for nucleic acid amplification.
authors.affiliation: Department of Chemistry, the Research Center in Infectiology and the Laboratory of Cell and Developmental Genetics, Université Laval, Québec City, Qc, Canada G1K 7P4.
authors.forename: Hoang A
authors.initials: HA
authors.lastname: Ho
authors.forename: Kim
authors.initials: K
authors.lastname: Doré
authors.forename: Maurice
authors.initials: M
authors.lastname: Boissinot
authors.forename: Michel G
authors.initials: MG
authors.lastname: Bergeron
authors.forename: Robert M
authors.initials: RM
authors.lastname: Tanguay
authors.forename: Denis
authors.initials: D
authors.lastname: Boudreau
authors.forename: Mario
authors.initials: M
authors.lastname: Leclerc
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D009696:Nucleic Acids / Q000032:analysis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D004277:DNA, Single-Stranded; D009696:Nucleic Acids; D004247:DNA