title: Highly sensitive and selective fluorescent assay for guanine based on the Cu(2+)/eosin Y system.
abstract: A fluorescent probe has been developed for the determination of guanine based on the quenched fluorescence signal of Cu(2+)/eosin Y. Cu(2+) interacted with eosin Y, resulting in fluorescence quenching. Subsequently, with the addition of guanine to the Cu(2+)/eosin Y system, guanine reacted with Cu(2+) to form 1:1 chelate cation, which further combined with eosin Y to form a 1:1 ternary ion-association complex by electrostatic attraction and hydrophobic interaction, resulting in significant decrease of the fluorescence. Hence, a fluorescent system was constructed for rapid, sensitive and selective detection of guanine with a detection limit as low as 1.5 nmol L(-1) and a linear range of 3.3-116 nmol L(-1). The method has been applied satisfactorily to the determination of guanine in DNA and urine samples with the recoveries from 98.7% to 105%. This study significantly expands the realm of application of ternary ion-association complex in fluorescence probe.
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China; Department of Basic Medical Sciences, Zhengzhou Shuqing Medical College, Zhengzhou 450064, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Shi
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Gong
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China. Electronic address: slfeng@htu.cn.
authors.forename: Suling
authors.initials: S
authors.lastname: Feng
mesh_terms: D000818:Animals; D002413:Cations, Divalent / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004801:Eosine Yellowish-(YS) / Q000737:chemistry*; D005399:Fishes; D005456:Fluorescent Dyes / Q000737:chemistry*; D006147:Guanine / Q000032:analysis* / Q000652:urine*; D006801:Humans; D057230:Limit of Detection; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D002413:Cations, Divalent; D005456:Fluorescent Dyes; D006147:Guanine; D003300:Copper; D004247:DNA; D004801:Eosine Yellowish-(YS)
keywords: Cu(2+); Eosin Y; Fluorescence probe; Guanine