An electrochemical aptasensor for chiral peptide detection using layer-by-layer assembly of polyelectrolyte-methylene blue/polyelectrolyte-graphene multilayer

• Published in: Analytica chimica acta 2012-01, Vol.712, p.127-131
• Main Authors: Qin, Haixia, Liu, Jiyang, Chen, Chaogui, Wang, JiaHai, Wang, Erkang
• Format: Article
• Language: English
• Subjects: Adsorption; Analytical chemistry; Applied sciences; Aptamer; Aptamers, Nucleotide - chemistry; Arginine Vasopressin - analysis; Assembly; Chemistry; Chiral peptide; Electrochemical aptasensor; Electrochemical methods; Electrochemical Techniques; Electrolytes - chemistry; Electron transfer; Exact sciences and technology; General, instrumentation; Global environmental pollution; Graphene; Graphite - chemistry; Layer-by-layer; Methylene blue; Methylene Blue - chemistry; Multilayers; Peptides; Peptides - analysis; Pollution; Polyelectrolytes; Stereoisomerism
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2011.10.044

[Display omitted] ► An electrochemical aptasensor for selective detection of peptide is constructed. ► This aptasensor is based on grapheme multilayer via layer-by-layer assembly. ► Such multilayer facilitates electron transfer and provides more adsorption sites. 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.