title: Anthraquinonyl glycoside facilitates the standardization of graphene electrodes for the impedance detection of lectins.
abstract: BACKGROUND
  Construction of electrochemical impedance sensors by the self-assembly technique has become a promising strategy for the 'label-free' detection of protein-ligand interactions. However, previous impedance sensors are devoid of an inherent electrochemical signal, which limits the standardization of the sensors for protein recognition in a reproducible manner.
  
  
  RESULTS
  We designed and synthesized an anthraquinonyl glycoside (AG) where the anthraquinone (AQ) moiety can bind to the surface of a graphene-based working electrode while the glycoside serving as a ligand for lectin. By measuring the inherent voltammetric signal of AQ, the glycosides decorated on the working electrode could be simply quantified to obtain electrodes with a unified signal window. Subsequently, impedance analysis showed that the 'standardized' electrodes gave a reproducible electrochemical response to a selective lectin with no signal variation in the presence of unselective proteins.
  
  
  CONCLUSIONS
  Anthraquinone-modified ligands could be used to facilitate the standardization of electrochemical impedance sensors for the reproducible, selective analysis of ligand-protein interactions.
authors.affiliation: Key Laboratory for Advanced Materials & Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237 PR China.
authors.forename: Bi-Wen
authors.initials: BW
authors.lastname: Zhu
authors.affiliation: Key Laboratory for Advanced Materials & Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237 PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Cai
authors.affiliation: Key Laboratory for Advanced Materials & Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237 PR China.
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: He
authors.affiliation: Key Laboratory for Advanced Materials & Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237 PR China.
authors.forename: Guo-Rong
authors.initials: GR
authors.lastname: Chen
authors.affiliation: Key Laboratory for Advanced Materials & Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Rd, Shanghai, 200237 PR China.
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Long
keywords: Anthraquinone; EIS; Electrochemistry; Glycoside; Graphene; Lectin; Standardization