title: Electrochemical immunosensor for simultaneous detection of multiplex cancer biomarkers based on graphene nanocomposites.
abstract: In this work, a sandwich-format electrochemical immunosensor for simultaneous determination of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) was fabricated using biofunctional carboxyl graphene nanosheets (CGS) as immunosensing probes, which were fabricated by means of immobilization of toluidine blue (TB) and labeled anti-CEA (Ab2,1), Prussian blue (PB) and anti-AFP (Ab2,2) successively on CGS. The capture anti-CEA (Ab1,1) and anti-AFP (Ab1,2) were immobilized onto the chitosan-Au nanoparticles (CHIT-AuNPs) modified electrode through 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxy succinimide (EDC/NHS). Experimental results revealed that this sandwich-type immunoassay enabled simultaneous detection of CEA and AFP with linear range of 0.5-60 ng mL(-1) for both analytes. The detection limit was 0.1 ng mL(-1) for CEA and 0.05 ng mL(-1) for AFP (S/N=3). The assay results of serum samples with the proposed method were in a good agreement with the reference values from the standard ELISA method. And the negligible cross-reactivity between the two analytes allows it to possess potential promise in clinical diagnosis.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Xinle
authors.initials: X
authors.lastname: Jia
authors.forename: Jingman
authors.initials: J
authors.lastname: Han
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Zhanfang
authors.initials: Z
authors.lastname: Ma
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000097:blood; D048271:Chitosan / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D009369:Neoplasms / Q000097:blood / Q000175:diagnosis; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D002272:Carcinoembryonic Antigen; D000509:alpha-Fetoproteins; D006046:Gold; D006108:Graphite; D048271:Chitosan
keywords: Alpha-fetoprotein; Carboxyl graphene nanosheet-Prussian blue; Carboxyl graphene nanosheet-toluidine blue; Carcinoembryonic antigen; Chitosan-Au nanoparticles