title: An electrochemical aptasensor for chiral peptide detection using layer-by-layer assembly of polyelectrolyte-methylene blue/polyelectrolyte-graphene multilayer.
abstract: Here we demonstrate for the first time that by physically adsorbing aptamer onto conductive film assembled via alternate adsorption of graphene/polyelectrolyte and methylene blue/polyelectrolyte, a label-free electrochemical aptasensor with high sensitivity and selectivity for peptide detection is constructed. Graphene multilayer derived from layer-by-layer assembly has played significant roles in this sensing strategy: allowing accumulation of methylene blue, facilitating electron transfer and providing much more adsorption site. As compared to previous electrochemical aptasensors, the current sensor based on graphene multilayer alternated with electroactive molecule layer offers extremely high capability for sensitive detection of target without interference of environmental surrounding. This electroactive probe-confined graphene multilayer confers great flexibility to combine with differential pulse voltammetry (DPV) together. In the presence of target d entiomer of arginine vasopressin (D-VP), the binding of peptide to aptamer block the electron transfer process of MB, leading to decreased current peak of DPV. By this way, this electrochemical aptasensor based on electroactive molecule-intercalated graphene multilayer provide highly sensitive and specific detection of D-VP with the lowest detectable concentration of 1 ng mL(-1) and a wide detection range from 1 to 265 ng mL(-1).
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Qin
authors.forename: Jiyang
authors.initials: J
authors.lastname: Liu
authors.forename: Chaogui
authors.initials: C
authors.lastname: Chen
authors.forename: JiaHai
authors.initials: J
authors.lastname: Wang
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001127:Arginine Vasopressin / Q000032:analysis; D055664:Electrochemical Techniques; D004573:Electrolytes / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry*; D010455:Peptides / Q000032:analysis*; D013237:Stereoisomerism
chemical_list: D052157:Aptamers, Nucleotide; D004573:Electrolytes; D010455:Peptides; D001127:Arginine Vasopressin; D006108:Graphite; D008751:Methylene Blue