title: High-selectivity electrochemical non-enzymatic sensors based on graphene/Pd nanocomposites functionalized with designated ionic liquids.
abstract: Nano-sized Pd particles are uniformly dispersed on graphene nanosheets (GNSs) using a supercritical-fluid-assisted deposition technique to increase the electrochemical sensing properties. The incorporation of different kinds of ionic liquid (IL) can increase the electrode sensing current toward different analytes. Butylmethylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (BMP-TFSI) IL is beneficial for glucose detection, whereas the electrode with butylmethylpyrrolidinium-dicyanamide (BMP-DCA) IL shows high sensitivity toward ascorbic acid (AA). The selective detection of glucose or AA from their mixture is for the first time demonstrated using a non-enzymatic electrode with the aid of an IL. Angle-resolved X-ray photoelectron spectroscopy analyses indicate that GNSs can create an aligned cation/anion orientation in the adsorbed IL film, with the anions preferentially occupying the topmost surface. As a result, the electrode sensitivity and selectivity are mainly determined by the IL constituent anions.
authors.affiliation: Institute of Materials Science and Engineering, National Central University, Taiwan.
authors.forename: Chueh-Han
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Institute of Materials Science and Engineering, National Central University, Taiwan.
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Yang
authors.affiliation: Institute of Materials Science and Engineering, National Central University, Taiwan; Department of Mechanical Engineering, National Central University, Taiwan; Department of Chemical and Materials Engineering, National Central University, Taiwan. Electronic address: jkchang@ncu.edu.tw.
authors.forename: Jeng-Kuei
authors.initials: JK
authors.lastname: Chang
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis; D015374:Biosensing Techniques / Q000379:methods; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D005947:Glucose / Q000032:analysis; D006108:Graphite / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D007094:Imides / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D057230:Limit of Detection; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D009861:Onium Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011759:Pyrrolidines / Q000737:chemistry*
chemical_list: D006845:Hydrocarbons, Fluorinated; D007094:Imides; D052578:Ionic Liquids; D009861:Onium Compounds; D011759:Pyrrolidines; C575299:bis(trifluoromethanesulfonyl)imide; D010165:Palladium; D006108:Graphite; D005947:Glucose; D001205:Ascorbic Acid; C000607438:1-butyl-1-methylpyrrolidinium
keywords: Angle-resolved X-ray photoelectron spectroscopy; Electrochemical sensing; Graphene; Ionic liquid; Selectivity