title: Indicator displacement assay for cholesterol electrochemical sensing using a calix[6]arene functionalized graphene-modified electrode.
abstract: A novel electrochemical method has been developed towards cholesterol detection based on competitive host-guest interaction by selecting methylene blue (MB) and calix[6]arene functionalized graphene (CX6-Gra) as the "reporter pair". In the presence of cholesterol, the MB molecules are displaced by cholesterol in the CX6-Gra.MB complex, leading to a "switch off" electrochemical response. A linear response range of 0.50 to 50.00 μM for cholesterol with a low detection limit of 0.20 μM (S/N = 3) was obtained by using the proposed method. This method could be successfully utilized to detect cholesterol in serum samples, and may be expanded to the analysis of other non-electroactive species. Besides, the host-guest interaction between cholesterol and CX6 was studied by molecular modeling calculations, which revealed that the complexation could reduce the energy of the system and the complex of a 1 : 1 host-guest stoichiometry had the lowest binding free energy of -8.01 kcal mol(-1). In addition, the constructed electrochemical sensing platform is important as it does not use any enzyme or antibody for the detection of cholesterol efficiently and selectively over common interfering species.
authors.affiliation: School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China. lcppp1974@sina.com.
authors.forename: Long
authors.initials: L
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Yucong
authors.initials: Y
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Ran
authors.forename: Guogang
authors.initials: G
authors.lastname: Deng
authors.forename: Yanqiong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hanzhang
authors.initials: H
authors.lastname: Ye
authors.forename: Genfu
authors.initials: G
authors.lastname: Zhao
authors.forename: Can-Peng
authors.initials: CP
authors.lastname: Li
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D002784:Cholesterol / Q000032:analysis* / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D005240:Feasibility Studies; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D008751:Methylene Blue / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D010636:Phenols; C476540:calix(6)arene; D047250:Calixarenes; D006108:Graphite; D002784:Cholesterol; D008751:Methylene Blue