title: Magnetic-field-assisted assembly of layered double hydroxide/metal porphyrin ultrathin films and their application for glucose sensors.
abstract: The ordered ultrathin films (UTFs) based on CoFe-LDH (layered double hydroxide) nanoplatelets and manganese porphyrin (Mn-TPPS) have been fabricated on ITO substrates via a magnetic-field-assisted (MFA) layer-by-layer (LBL) method and were demonstrated as an electrochemical sensor for glucose. The XRD pattern for the film indicates a long-range stacking order in the normal direction of the substrate. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the MFA LDH/Mn-TPPS UTFs reveal a continuous and uniform surface morphology. Cyclic voltammetry, impedance spectroscopy, and chronoamperometry were used to evaluate the electrochemical performance of the film, and the results show that the MFA-0.5 (0.5 T magnetic field) CoFe-LDH/Mn-TPPS-modified electrode displays the strongest redox current peaks and fastest electron transfer process compared with those of MFA-0 (without magnetic-field) and MFA-0.15 (0.15 T magnetic field). Furthermore, the MFA-0.5 CoFe-LDH/Mn-TPPS exhibits remarkable electrocatalytic activity toward the oxidation of glucose with a linear response range (0.1-15 mM; R(2) = 0.999), low detection limit (0.79 μM) and high sensitivity (66.3 μA mM(-1) cm(-2)). In addition, the glucose sensor prepared by the MFA LBL method also shows good selectivity and reproducibility as well as resistance to poisoning in a chloride ion solution. Therefore, the novel strategy in this work creates new opportunities for the fabrication of nonenzyme sensors with prospective applications in practical detection.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Mingfei
authors.initials: M
authors.lastname: Shao
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Xu
authors.forename: Jingbin
authors.initials: J
authors.lastname: Han
authors.forename: Jingwen
authors.initials: J
authors.lastname: Zhao
authors.forename: Wenying
authors.initials: W
authors.lastname: Shi
authors.forename: Xianggui
authors.initials: X
authors.lastname: Kong
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.forename: David G
authors.initials: DG
authors.lastname: Evans
authors.forename: Xue
authors.initials: X
authors.lastname: Duan
mesh_terms: D004566:Electrodes; D005947:Glucose / Q000032:analysis*; D006878:Hydroxides / Q000737:chemistry*; D008280:Magnetics; D008567:Membranes, Artificial; D008665:Metalloporphyrins / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D006878:Hydroxides; D008567:Membranes, Artificial; D008665:Metalloporphyrins; C031356:hydroxide ion; D005947:Glucose