title: Layer-by-layer assembled multilayer films of exfoliated layered double hydroxide and carboxymethyl-β-cyclodextrin for selective capacitive sensing of acephatemet.
abstract: Novel organic-inorganic hybrid ultrathin films were fabricated by alternate assembly of cationic exfoliated Mg-Al-layered double hydroxide (LDH) nanosheets and carboxymethyl-β-cyclodextrin (CMCD) as a polyanion onto a glassy carbon electrode (GCE) via a layer-by-layer (LBL) approach. The multilayer films were then characterized by means of X-ray powder diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM). These films were found to possess a long range stacking order in the normal direction of the substrate with a continuous and uniform morphology. Its electrochemical performance was systematically investigated. Our results demonstrate that such a newly designed (LDH/CMCD)n multilayer film, combining the individual properties of CMCD (a high supramolecule recognition and enrichment capability) together with LDH nanosheets (a rigid inorganic matrix), can be applied to a sensitive, simple, and label-free capacitive detection of acephatemet (AM). Molecular docking calculations further disclose that the selective sensing behavior toward AM may be attributed to the specific binding ability of CMCD to AM. Under the optimized conditions, the capacitive change of AM was proportional to its concentration ranging from 0.001 to 0.10 μg mL(-1) and 0.1 to 0.8 μg mL(-1) with a detection limit 0.6 ng mL(-1) (S/N=3). Toward the goal for practical applications, this simple probe was further evaluated by monitoring AM in real samples.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China. Electronic address: jmgong@mail.ccnu.edu.cn.
authors.forename: Jingming
authors.initials: J
authors.lastname: Gong
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Han
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China. Electronic address: xlzhu@mail.ccnu.edu.cn.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China.
authors.forename: Zhangqiong
authors.initials: Z
authors.lastname: Guan
mesh_terms: D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006878:Hydroxides / Q000737:chemistry*; D057230:Limit of Detection; D062105:Molecular Docking Simulation; D049329:Nanostructures / Q000737:chemistry; D010755:Organophosphates / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D006878:Hydroxides; D010755:Organophosphates; D010575:Pesticides; D047392:beta-Cyclodextrins; C441457:carboxymethyl-beta-cyclodextrin; C031356:hydroxide ion
keywords: Capacitive sensor; Carboxymethyl-β-cyclodextrin; Exfoliated layered double hydroxide; Layer-by-layer assembly; Organophosphate pesticides