title: A simultaneous electrochemical multianalyte immunoassay of high sensitivity C-reactive protein and soluble CD40 ligand based on reduced graphene oxide-tetraethylene pentamine that directly adsorb metal ions as labels.
abstract: A simplified electrochemical multianalyte immunosensor for the simultaneous detection of high sensitivity C-reactive protein (hsCRP) and soluble CD40 ligand (sCD40L) that uses reduced graphene oxide-tetraethylene pentamine (rGO-TEPA) that directly adsorbs metal ions as labels is reported. rGO-TEPA contains a large number of amino groups and has excellent conductivity, making it an ideal template for the loading of Pb(2+) and Cu(2+), which greatly amplifies the detection signals. The signals could be directly detected in a single run through differential pulse voltammetry (DPV), and each biorecognition event produces a distinct voltammetric peak. The position and size of each peak reflects the identity and the level of the corresponding antigen. Primarily designed for an application in a sandwich-type immunoassay based on Pb(2+) and Cu(2+) labels, two main challenges are accomplished with the herein presented nanosheets: fabrication of the template and the amination process for Pb(2+) and Cu(2+) adsorption. To further improve the analytical performance of the immunosensor, Au@bovine serum albumin (BSA) nanospheres synthesized through a "green" synthesis route were used as a sensor platform, which not only provides a biocompatible microenvironment for the immobilization of antibodies but also amplifies the electrochemical signals. Under optimal conditions, hsCRP and sCD40L could be assayed in the range of 0.05 to 100 ng mL(-1) with detection limits of 16.7 and 13.1 pg mL(-1) (S/N=3), respectively. The assay results on clinical serum samples with the proposed immunosensor were in acceptable agreement with those using the standard single-analyte test of the enzyme-linked immunosorbent assay (ELISA). This novel immunosensing system provides a simple, sensitive and low-cost approach for a multianalyte immunoassay.
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Guolin
authors.initials: G
authors.lastname: Yuan
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yu
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Chunyong
authors.initials: C
authors.lastname: Xia
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Liuliu
authors.initials: L
authors.lastname: Gao
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Wailan
authors.initials: W
authors.lastname: Xu
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: hejunlin_11@aliyun.com.
authors.forename: Junlin
authors.initials: J
authors.lastname: He
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods; D002097:C-Reactive Protein / Q000032:analysis*; D023201:CD40 Ligand / Q000032:analysis / Q000097:blood*; D002413:Cations, Divalent / Q000302:isolation & purification; D003300:Copper / Q000302:isolation & purification*; D055664:Electrochemical Techniques / Q000379:methods; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007854:Lead / Q000302:isolation & purification*; D057230:Limit of Detection; D008958:Models, Molecular; D054118:Nanospheres / Q000737:chemistry / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D002413:Cations, Divalent; D010087:Oxides; D000644:Quaternary Ammonium Compounds; D023201:CD40 Ligand; D007854:Lead; C040648:pentamine; D006046:Gold; D006108:Graphite; D003300:Copper; D002097:C-Reactive Protein
keywords: High sensitive C-reactive protein; Metal ion labels; Reduced graphene oxide-tetraethylene pentamine; Simultaneous detection; Soluble CD40 ligand