title: Colloidal gold-polystyrene bead hybrid for chemiluminescent detection of sequence-specific DNA.
abstract: A sensitive chemiluminescent (CL) detection of sequence-specific DNA has been developed by taking advantage of a magnetic separation/mixing process and the amplification feature of colloidal gold labels. In this protocol, the target oligonucleotides are hybridized with magnetic bead-linked capture probes, followed by the hybridization of the biotin-terminated amplifying DNA probes and the binding of streptavidin-coated gold nanoparticles; the nanometer-sized gold tags are then dissolved and quantified by a simple and sensitive luminol CL reaction. The proposed CL protocol is evaluated for a 30-base model DNA sequence, and the amount as low as 0.01 pmol of DNA is determined, which exhibits a 150 x enhancement in sensitivity over previous gold dissolution-based electrochemical formats and an enhancement of 20 x over the ICPMS detection. Further signal amplification is achieved by the assembly of biotinylated colloidal gold onto the surface of streptavidin-coated polystyrene beads. Such amplified CL transduction allows detection of DNA targets down to the 100 amol level, and offers great promise for ultrasensitive detection of other biorecognition events.
authors.affiliation: School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Fan
authors.forename: Choiwan
authors.initials: C
authors.lastname: Lau
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Lu
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D001483:Base Sequence; D004247:DNA / Q000032:analysis*; D015342:DNA Probes; D017979:Gold Colloid; D008163:Luminescent Measurements; D008969:Molecular Sequence Data; D049329:Nanostructures; D011137:Polystyrenes; D012680:Sensitivity and Specificity; D019809:Streptavidin
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D015342:DNA Probes; D017979:Gold Colloid; D011137:Polystyrenes; C030325:anthrax toxin; D004247:DNA; D019809:Streptavidin