title: Highly-sensitive label-free electrochemical carcinoembryonic antigen immunosensor based on a novel Au nanoparticles-graphene-chitosan nanocomposite cryogel electrode.
abstract: For the first time, a simple and highly sensitive label-free electrochemical carcinoembryonic antigen (CEA) immunosensor based on a cryogel electrode has been developed and tested. The as-prepared nanocomposite combined the advantages of the graphene, AuNPs and chitosan (AuNPs-GP-CS) together with the ease of preparing a cryogel coupled to a silver deposition, to act as a redox mediator, on a Au electrode. Under the optimal conditions, the decrease of the cyclic voltammetry (CV) silver peak current was proportional to the CEA concentration over a range of from 1.0×10(-6) to 1.0 ng mL(-1) with a detection limit of 2.0×10(-7) ng mL(-1). This AuNPs-GP-CS cryogel electrode gave a 1.7 times higher sensitivity and 25 times lower detection limit than the non-cryogel electrode. Moreover, the proposed electrochemical immunosensor exhibited good selectivity, reproducibility and stability. When applied to analyse clinical serum samples, the data determined by the developed immunosensor were in agreement with those obtained by the current hospital analysis system (enzyme linked fluorescent assay) (P>0.05), to indicate that the immunosensor would be potentially useful for clinical diagnostics.
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Saluma
authors.initials: S
authors.lastname: Samanman
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Apon
authors.initials: A
authors.lastname: Numnuam
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Applied Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Warakorn
authors.initials: W
authors.lastname: Limbut
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Proespichaya
authors.initials: P
authors.lastname: Kanatharana
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand. Electronic address: panote.t@psu.ac.th.
authors.forename: Panote
authors.initials: P
authors.lastname: Thavarungkul
mesh_terms: D015374:Biosensing Techniques; D002272:Carcinoembryonic Antigen / Q000097:blood*; D048271:Chitosan / Q000737:chemistry; D059985:Cryogels / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D002272:Carcinoembryonic Antigen; D059985:Cryogels; D006046:Gold; D006108:Graphite; D048271:Chitosan
keywords: Carcinoembryonic antigen; Cryogel; Electrochemical immunosensor; Gold nanoparticles–graphene–chitosan nanocomposite; Redox mediator; Ultrasensitive