title: All-graphene composite materials for signal amplification toward ultrasensitive electrochemical immunosensing of tumor marker.
abstract: Graphene has shown great potential for use in biosensors because of its versatile surface modification, good water dispersibility, and extraordinary electrical conductivity. Here, a novel enzyme-free and all-graphene electrochemical immunosensor, based on two novel graphene nanocomposites, for the ultrasensitive immunosensing of α-fetoprotein (AFP) was reported. Noncovalent ultrathin gold nanowire functionalized graphene sheets (GNWs/GO) with the extraordinary biological and electrical properties, which exhibited high water solubility and further biological molecule functionalization, was prepared in situ solution phase to be used as an enhanced electrochemical sensing platform. In addition, a new electrocatalyst, CuS nanoparticle-decorated graphene (CuS/GO) composites was successfully prepared by a simple method for in situ growth of CuS on the surface of graphene sheets. Covalent binding of the detection antibody of AFP on the CuS/GO composites produced a sensitive electrochemical bioprobe for detection of AFP by sandwich immunosensing. The corresponding immunosensor, employing an inexpensive and portable 3D paper-based analytical device, possessed a wide calibration range of 0.001-10 ng mL(-1) and a low detection limit of 0.5 pg mL(-1) (S/N=3), which was successfully applied to the detection of AFP in serum samples from both healthy people and cancer patients. The present work thus demonstrated the promising application of graphene-based nanocomposites in developing highly sensitive, environmentally friendly, and cost-effective electrochemical biosensors.
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Long
authors.initials: L
authors.lastname: Li
authors.affiliation: Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, PR China.
authors.forename: Lina
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Yu
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: chm_gesg@163.com.
authors.forename: Shenguang
authors.initials: S
authors.lastname: Ge
authors.affiliation: Cancer Research Center Shandong Tumor Hospital, Jinan 250117, PR China.
authors.forename: Xianrang
authors.initials: X
authors.lastname: Song
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D003300:Copper / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D053770:Nanowires / Q000737:chemistry / Q000648:ultrastructure; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis; D010209:Paper; D013440:Sulfides / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D013440:Sulfides; D000509:alpha-Fetoproteins; D006046:Gold; D006108:Graphite; D003300:Copper
keywords: Copper sulfide; Gold nanowires; Graphene; Paper-based electrochemical immunodevice