title: G-quadruplex-modulated fluorescence detection of potassium in the presence of a 3500-fold excess of sodium ions.
abstract: A label-free detection of K(+) was developed using G-quadruplex DNA (c-Myc) modulated fluorescence enhancement of tetrakis-(diisopropylguanidino) zinc phthalocyanine (Zn-DIGP). Upon the addition of increasing concentrations of potassium, a detection limit of 0.8 μM for K(+) was easily achieved. Comparative titrations using sodium, lithium, ammonium, transition metal, or alkali earth salts revealed that the fluorescence enhancement was highly specific for potassium ions. This system has, for the first time, provided a means for detecting 40 μM of K(+) even in the presence of a 3500-fold excess of Na(+) ions.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Qin
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Ren
authors.forename: Jiahai
authors.initials: J
authors.lastname: Wang
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Luedtke
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D054856:G-Quadruplexes; D007211:Indoles / Q000737:chemistry; D054833:Isoindoles; D008094:Lithium / Q000737:chemistry; D008672:Metals, Alkali / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D011188:Potassium / Q000032:analysis*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012964:Sodium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D028561:Transition Elements / Q000737:chemistry; D017967:Zinc Compounds
chemical_list: D007211:Indoles; D054833:Isoindoles; D008672:Metals, Alkali; D009942:Organometallic Compounds; D016271:Proto-Oncogene Proteins c-myc; D000644:Quaternary Ammonium Compounds; D028561:Transition Elements; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine; D008094:Lithium; D012964:Sodium; D011188:Potassium