title: Dynamic-light-scattering-based sequence-specific recognition of double-stranded DNA with oligonucleotide-functionalized gold nanoparticles.
abstract: An ultrasensitive and simple dynamic-light-scattering (DLS) assay for the sequence-specific recognition of double-stranded DNA (dsDNA) was developed based on detection of the average diameter change of Au nanoparticle (AuNP) probes modified with oligonucleotides 5'-TTTCTCTTCCTT- CTCTTC-(T)(12)-SH-3' (Oligo 1) and 5'-TTCTTTCTTTTCTTTTTC-(T)(12)- SH-3' (Oligo 2). The target dsDNA was composed of two complementary oligonucleotides: 5'-AAAGAGAAGGAAGAGAAGAAGAAAGAAAAGAAAAAG-3' (Oligo 3) and 3'-TTTCTCTTCCTTCTCTTCTTCTTTCTTTTCTTTTTC-5' (Oligo 4). Hybridization of the two AuNPs-Oligo probes with the target dsDNA induced aggregation of the target dsDNA by forming triplex DNA, which accordingly increased the average diameter. This diameter change could then be detected by DLS. The average diameter was proportional to the target dsDNA concentration over the range from 593 fM to 40 pM, with a detection limit of 593 fM. Moreover, the assay had good sequence specificity for the target dsDNA.
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China.
authors.forename: Xiang-Min
authors.initials: XM
authors.lastname: Miao
authors.forename: Cen
authors.initials: C
authors.lastname: Xiong
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Wang
authors.forename: Lian-Sheng
authors.initials: LS
authors.lastname: Ling
authors.forename: Xin-Tao
authors.initials: XT
authors.lastname: Shuai
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry*; D012542:Scattering, Radiation
chemical_list: D009841:Oligonucleotides; C051802:triplex DNA; D006046:Gold; D004247:DNA