title: Ultrasensitive electrochemical immunosensor based on orderly oriented conductive wires for the detection of human monocyte chemotactic protein-1 in serum.
abstract: For the first time, a simple, ultrasensitive and label-free electrochemical monocyte chemotactic protein-1 (MCP-1) immunosensor based on orderly oriented conductive wires has been developed. A conductive wire, which is similar to an electron-conducting tunnel, was designed with Au nanoparticles (AuNPs) joined to Au@Pt core-shell microspheres via a cysteamine (CA) crosslinker. To enhance the sensitivity of the immunosensor, Au nanoparticles were electrodeposited onto the gold electrode, and CA was self-assembled via strong Au-S covalent bonds, providing an appropriate surface and promoting electron transfer. Next, Au@Pt core-shell microspheres with large surface area were grafted onto the modified electrode to immobilize more MCP-1 antibodies. MCP-1 is an initiating factor and biomarker of atherosclerotic diseases. Under optimal experimental conditions, differential pulse voltammetry (DPV) current changes were used to detect MCP-1 with a broad linear range of 0.09-360 pg mL(-1) and a low detection limit of 0.03 pg mL(-1) (S/N=3). The proposed immunosensor exhibited good selectivity, reproducibility and reusability. When applied to spiked serum samples, the data for the developed immunosensor were in agreement with an enzyme linked immunosorbent assay, suggesting that the electrochemical immunosensor would be suitable for practical detection.
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Life Science and School of Public Health, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Junlin
authors.initials: J
authors.lastname: He
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. Electronic address: yuchaom@163.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Yu
mesh_terms: D018932:Chemokine CCL2 / Q000097:blood*; D003217:Conductometry / Q000295:instrumentation*; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008832:Microchemistry; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D018932:Chemokine CCL2
keywords: Atherosclerotic disease; Au electrodeposition; Au@Pt core–shell microspheres; Cysteamine; Monocyte chemotactic protein-1