title: Multiplex electrochemiluminescence immunoassay of two tumor markers using multicolor quantum dots as labels and graphene as conducting bridge.
abstract: A multiplex electrochemiluminescence (ECL) immunoassay for simultaneous determination of two different tumor markers, alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), using multicolor quantum dots as labels and graphene as conducting bridge was developed. Herein, a typical sandwich immune complex was constructed on the glass carbon electrode, with QDs525 and QDs625 labeled on secondary anti-AFP and anti-CEA antibodies, respectively, thus to obtain distinguishable ECL signals. Because most of those QDs labeled on secondary antibodies were beyond the space domain of the ECL reaction, graphene was used as a conducting bridge to promote the electron transfer between QDs and the electrode, leading to about 30-fold enhancement of the ECL intensity. Experimental results revealed that the multiplex electrochemiluminescence immunoassay enabled the simultaneous monitoring of AFP and CEA in a single run with a working range of 0.001-0.1 pg/mL. The detection limit (LOD) for both analytes at 0.4 fg/mL was very low. No obvious cross-reactivity was found. Precision, recovery and stability were satisfactory. This novel multiplex ECL immunoassay provided a simple, sensitive, specific and reliable alternative for the simultaneous detection of tumor markers in clinical laboratory.
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, PR China. nbuguo@163.com
authors: Zhiyong
authors: Z
authors: Guo
authors: Tingting
authors: T
authors: Hao
authors: Shuping
authors: S
authors: Du
authors: Beibei
authors: B
authors: Chen
authors: Zebo
authors: Z
authors: Wang
authors: Xing
authors: X
authors: Li
authors: Sui
authors: S
authors: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000097:blood; D055664:Electrochemical Techniques / Q000379:methods; D006108:Graphite; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D045663:Quantum Dots; D012463:Saliva / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D000509:alpha-Fetoproteins; D006108:Graphite