title: DNA interaction probed by evanescent wave cavity ring-down absorption spectroscopy via functionalized gold nanoparticles.
abstract: Evanescent wave cavity ring-down absorption spectroscopy (EW-CRDS) is employed to study interaction and binding kinetics of DNA strands by using gold nanoparticles (Au NPs) as sensitive reporters. These Au NPs are connected to target DNA of study that hybridizes with the complementary DNA fixed on the silica surface. By the absorbance of Au NPs, the interaction between two DNA strands may be examined to yield an adsorption equilibrium constant of 2.2×10(10) M(-1) using Langmuir fit. The binding efficiency that is affected by ion concentration, buffer pH and temperature is also examined. This approach is then applied to the label-free detection of the DNA mutation diseases using the sandwich hybridization assay. For monitoring a gene associated with sickle-cell anemia, the detection limit and the adsorption equilibrium constant is determined to be 1.2 pM and (3.7±0.8)×10(10) M(-1), distinct difference from the perfectly matched DNA sequence that yields the corresponding 0.5 pM and (1.1±0.2)×10(11) M(-1). The EW-CRDS method appears to have great potential for the investigation of the kinetics of a wide range of biological reactions.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 106, Taiwan.
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Yao
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 106, Taiwan. Electronic address: kclin@ntu.edu.tw.
authors.forename: King-Chuen
authors.initials: KC
authors.lastname: Lin
mesh_terms: D065966:Absorption, Physicochemical; D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization; D009994:Osmolar Concentration; D012822:Silicon Dioxide / Q000737:chemistry; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D006046:Gold; D012822:Silicon Dioxide; D004247:DNA
keywords: DNA interaction; DNA sensing; Evanescent wave cavity ring-down absorption spectroscopy; Gold nanoparticles; Sickle-cell disease