title: Ultrasensitive immunoassay based on anodic near-infrared electrochemiluminescence from dual-stabilizer-capped CdTe nanocrystals.
abstract: A sandwich-typed near-infrared (NIR) electrochemiluminescence (ECL) immunoassay was developed with dual-stabilizer-capped CdTe nanocrystals (NCs) as ECL labels and α fetoprotein antigen (AFP) as model protein. The dual-stabilizer-capped NIR CdTe NCs were promising ECL labels because of their NIR ECL emission of 800 nm, low anodic ECL potential of +0.85 V, and high biocompatibity, which can facilitate interference-free and highly sensitive ECL bioassays. Upon the immunorecognition of the immobilized AFP to its antibody labeled with dual-stabilizer-capped CdTe NCs, the proposed immunoassay displayed increasing ECL intensity, leading to a wide calibration range of 10.0 pg/mL to 80.0 ng/mL with a detection limit of 5.0 pg/mL [signal-to-noise ratio (S/N) = 3] without coupling any signal amplification procedures. The NIR ECL immunoassay for real samples displayed very similar results with those of Ru(bpy)(3)(2+) reagent kit based commercial ECL immunoassay, which not only proved for the efficiency of NIR ECL from dual-stabilizer-capped CdTe NCs but also paved the road for development of novel ECL emitters and corresponding reagent kits.
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Liang
authors.forename: Shufeng
authors.initials: S
authors.lastname: Liu
authors.forename: Guizheng
authors.initials: G
authors.lastname: Zou
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods / Q000592:standards*; D004566:Electrodes; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards; D008163:Luminescent Measurements / Q000379:methods / Q000592:standards*; D053758:Nanoparticles / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared / Q000379:methods / Q000592:standards*; D013691:Tellurium / Q000737:chemistry*
chemical_list: D002104:Cadmium; D013691:Tellurium