title: A novel sandwiched electrochemiluminescence immunosensor for the detection of carcinoembryonic antigen based on carbon quantum dots and signal amplification.
abstract: In this study, a novel sandwiched electrochemiluminescence (ECL) immunosensor for the detection of carcinoembryonic antigen (CEA) was developed. The nanocomposite of polydopamine and Ag nanoparticles (PDA-AgNPs) was prepared by the redox reaction between Ag+and dopamine. This nanocomposite not only provided an effective matrix for the immobilization of primary antibody (Ab1) but also enhanced the conductivity of the electrode. Carbon quantum dots (CQDs) were immobilized on the poly(ethylenimine) functionalized graphene oxide (PEI-GO) through amido-bond. Then Au nanoparticles were decorated on the CQDs modified PEI-GO matrix, and the resulted complex AuNPs/CQDs-PEI-GO was introduced to link secondary antibody (Ab2). The CQDs can be connected to the electrode surface through the combination of CEA with Ab1and Ab2, and then the amplified electrochemiluminescence signal of CQDs was obtained with the synergistic effect of AgNPs, polydopamine, AuNPs and PEI-GO. Under the optimal conditions, the ECL intensity was proportional to the logarithm value of CEA concentration in the linear range from 5pgmL-1to 500ngmL-1with a detection limit of 1.67pgmL-1for CEA detection. The immunosensor was applied for the CEA detection in real samples with satisfactory results. The proposed ECL immunosensor showed good performance with high sensitivity, specificity, reproducibility, stability and will be potential in clinical detection.
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China.
authors.forename: Nian-Lu
authors.initials: NL
authors.lastname: Li
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Jia
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China.
authors.forename: Rong-Na
authors.initials: RN
authors.lastname: Ma
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Jia
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China.
authors.forename: Yi-Yang
authors.initials: YY
authors.lastname: Lu
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China.
authors.forename: Sha-Shan
authors.initials: SS
authors.lastname: Shi
authors.affiliation: Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China. Electronic address: hswang@lcu.edu.cn.
authors.forename: Huai-Sheng
authors.initials: HS
authors.lastname: Wang
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D002244:Carbon / Q000737:chemistry*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007211:Indoles / Q000737:chemistry*; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry
chemical_list: D055910:Antibodies, Immobilized; D002272:Carcinoembryonic Antigen; D007211:Indoles; D011108:Polymers; C568283:polydopamine; D012834:Silver; D002244:Carbon; D006046:Gold; D006108:Graphite; D011094:Polyethyleneimine
keywords: Carbon quantum dots; Carcinoembryonic antigen; Electrochemiluminescence immunosensor; Functionalized graphene oxide