title: Superior fluorescent probe for detection of potassium ion.
abstract: Here, a simple, and highly sensitive fluorescent assay is designed to monitor K(+). The versatile, robust biosensing strategy is based on the specific recognition utility of label-free aptamers with their targets and PicoGreen dye as the signal probe. The aptamers undergo a conformational change to a secondary structure such as G-quadruplex in the presence of targets. In addition to a conformational change with its targets, the remaining single-stranded DNA (ssDNA) aptamer form a duplex structure with its complete complementary sequence. Conformational changes of aptamers as well as fluorescence amplification produce clear signal-off in the presence of targets. Fluorescent assay employing this mechanism for the detection of K(+) is highly sensitive, and selective. The detection limit of the K(+) assay is determined to be 2.37 pM. The sensing strategy is low-cost and simple in its operation without requirement for complex labeling of probe DNA or sophisticated synthesis of the fluorescent compound. Also, the method has less structural requirement of complexes of aptamers with their targets, thus rending its wilder applications for various targets.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China. Electronic address: czb979216@sina.com.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Liangyu
authors.initials: L
authors.lastname: Hu
authors.affiliation: Beijing Research Center for Agricultural Standards and Testing, Beijing 100097, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Luan
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D009930:Organic Chemicals / Q000737:chemistry; D011188:Potassium / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D014867:Water / Q000032:analysis
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C099476:PicoGreen; D014867:Water; D011188:Potassium
keywords: Aptamer; Fluorescence; PicoGreen dye; Potassium ion