title: Integrating a DNA Strand Displacement Reaction with a Whispering Gallery Mode Sensor for Label-Free Mercury (II) Ion Detection.
abstract: Mercury is an extremely toxic chemical pollutant of our environment. It has attracted the world's attention due to its high mobility and the ease with which it accumulates in organisms. Sensitive devices and methods specific for detecting mercury ions are, hence, in great need. Here, we have integrated a DNA strand displacement reaction with a whispering gallery mode (WGM) sensor for demonstrating the detection of Hg(2+) ions. Our approach relies on the displacement of a DNA hairpin structure, which forms after the binding of mercury ions to an aptamer DNA sequence. The strand displacement reaction of the DNA aptamer provides highly specific and quantitative means for determining the mercury ion concentration on a label-free WGM sensor platform. Our approach also shows the possibility for manipulating the kinetics of a strand displacement reaction with specific ionic species.
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China. wufengchi@mail.ipc.ac.cn.|University of Chinese Academy of Sciences, Beijing 100080, China. wufengchi@mail.ipc.ac.cn.|Laboratory of Nanophotonics &amp; Biosensing, Max Planck Institute for the Science of Light, Erlangen D-91058, Germany. wufengchi@mail.ipc.ac.cn.
authors.forename: Fengchi
authors.initials: F
authors.lastname: Wu
authors.affiliation: Laboratory of Nanophotonics &amp; Biosensing, Max Planck Institute for the Science of Light, Erlangen D-91058, Germany. yuqiang.wu@gmail.com.
authors.forename: Yuqiang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China. niu@mail.ipc.ac.cn.
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Niu
authors.affiliation: Laboratory of Nanophotonics &amp; Biosensing, Max Planck Institute for the Science of Light, Erlangen D-91058, Germany. frank.vollmer@mpl.mpg.de.|Division of Biomedical Engineering, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. frank.vollmer@mpl.mpg.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Vollmer
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D007477:Ions / Q000737:chemistry / Q000302:isolation & purification*; D008628:Mercury / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D007477:Ions; D004247:DNA; D008628:Mercury
keywords: DNA nanotechnology; DNA strand displacement; Mercury (II) ions detection; biosensing; label-free detection; optical microcavity; whispering gallery mode