title: Determination of nucleic acids by near-infrared fluorescence quenching of hydrophobic thiacyanine dye in the presence of Triton X-100.
abstract: A near-infrared (near-IR) fluorescence quenching method was developed for the determination of nucleic acids in aqueous solution by using a cationic heptamethylene thiacyanine as a probe. The near-IR cationic cyanine showed maximum excitation and emission wavelengths at 800 and 825 nm, respectively, in the presence of Triton X-100; the fluorescence of the cyanine could be greatly quenched by DNA. The calibration graphs were linear over the range of 10-400 ng/mL for CT (calf thymus) DNA and over the range 5-400 ng/mL for FS (fish sperm) DNA under optimal conditions. The corresponding detection limits were 5.2 ng/mL for CT DNA and 2.5 ng/mL for FS DNA. The relative standard deviation (n = 8) was 3.1% for 75 ng/mL CT DNA and 2.2% for 75 ng/mL FS DNA, respectively. Preliminary research showed that the fluorescence quenching might be ascribed to the formation of dye aggregate facilitated by DNA.
authors.affiliation: The Key Laboratory of Analytical Science of MOE, Department of Chemistry, Xiamen University, Xiamen 361005, China.
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Zhu
authors.forename: Yu-Qin
authors.initials: YQ
authors.lastname: Wu
authors.forename: Hong
authors.initials: H
authors.lastname: Zheng
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Chen
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Li
authors.forename: Shun-Hua
authors.initials: SH
authors.lastname: Li
authors.forename: Jin-Gou
authors.initials: JG
authors.lastname: Xu
mesh_terms: D000818:Animals; D002232:Carbocyanines / Q000737:chemistry*; D004247:DNA / Q000032:analysis*; D005453:Fluorescence; D017830:Octoxynol / Q000737:chemistry*; D009994:Osmolar Concentration; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D002232:Carbocyanines; D017830:Octoxynol; D004247:DNA