title: Label-free graphene biosensor targeting cancer molecules based on non-covalent modification.
abstract: A label-free immunosensor based on antibody-modified graphene field effect transistor (GFET) was presented. Antibodies targeting carcinoembryonic antigen (Anti-CEA) were immobilized to the graphene surface via non-covalent modification. The bifunctional molecule, 1-pyrenebutanoic acid succinimidyl ester, which is composed of a pyrene and a reactive succinimide ester group, interacts with graphene non-covalently via π-stacking. The succinimide ester group reacts with the amine group to initiate antibody surface immobilization, which was confirmed by X-ray Photoelectron Spectroscopy, Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. The resulting anti-CEA modified GFET sufficiently monitored the reaction between CEA protein and anti-CEA in real-time with high specificity, which revealed selective electrical detection of CEA with a limit of detection (LOD) of less than 100pg/ml. The dissociation constant between CEA protein and anti-CEA was estimated to be 6.35×10-11M, indicating the high affinity and sensitivity of anti-CEA-GFET. Taken together, the graphene biosensors provide an effective tool for clinical application and point-of-care medical diagnostics.
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. Electronic address: hjmao@mail.sim.ac.cn.
authors.forename: Hongju
authors.initials: H
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; Shanghai University, Shanghai 200031, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; ShanghaiTech University, Shanghai 200444, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Honglian
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Chunping
authors.initials: C
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Qinghui
authors.initials: Q
authors.lastname: Jin
authors.affiliation: School of Electronic Engineering, Bangor University, Bangor LL57 1UT, UK.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Transducer Technology, Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. Electronic address: jlzhao@mail.sim.ac.cn.
authors.forename: Jianlong
authors.initials: J
authors.lastname: Zhao
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D014408:Biomarkers, Tumor / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation*; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D055664:Electrochemical Techniques / Q000295:instrumentation; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D057230:Limit of Detection; D019095:Point-of-Care Systems
chemical_list: D055910:Antibodies, Immobilized; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D006108:Graphite
keywords: CEA protein; Dissociation constant; Graphene; Non-covalent modification