title: A novel label-free electrochemical immunosensor based on functionalized nitrogen-doped graphene quantum dots for carcinoembryonic antigen detection.
abstract: A novel and ultrasensitive label-free electrochemical immunosensor was fabricated for quantitative detection of carcino-embryonic antigen (CEA). The nitrogen-doped graphene quantum dots (N-GQDs) supported PtPd bimetallic nanoparticles (PtPd/N-GQDs) were synthesized by a simple and green hydrothermal procedure. Subsequently, PtPd/N-GQDs functionalized Au nanoparticles (PtPd/N-GQDs@Au) were prepared successfully via a self-assembly approach. Because of the synergetic effect present in PtPd/N-GQDs@Au, this novel nanocomposites has shown excellent electrocatalytic activity towards hydrogen peroxide (H2O2) reduction. Featuring good biocompatibility, excellent conductivity and large surface area, PtPd/N-GQDs@Au was applied as transducing materials to efficiently conjugate capture antibodies and amplify electrochemical signal. Under the optimal conditions, the proposed immunosensor was used for the detection of CEA with wide dynamic range in the range from 5 fg/mL to 50ng/mL with a low detection limit of 2fg/mL (S/N=3). Furthermore, this label-free immunosensor possesses high sensitivity, special selectivity and long-term stability, which shows promising application in bioassay analysis.
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Yang
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China. Electronic address: qingliu0315@163.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Jianjian
authors.initials: J
authors.lastname: Cui
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Yueyun
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Analysis and Testing Center, Shandong University of Technology, Zibo 255049, PR China.
authors.forename: Zengdian
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China. Electronic address: dyh651118@126.com.
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Dong
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques; D002272:Carcinoembryonic Antigen / Q000737:chemistry / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D045663:Quantum Dots
chemical_list: D055910:Antibodies, Immobilized; D002272:Carcinoembryonic Antigen; D006046:Gold; D006108:Graphite; D006861:Hydrogen Peroxide
keywords: Au nanoparticles; Carcinoembryonic antigen; Electrochemical immunosensor; Label-free; Nitrogen-doped graphene quantum dots; PtPd bimetallic nanoparticles