A novel immunosensor for squamous cell carcinoma antigen determination based on CdTe@Carbon dots nanocomposite electrochemiluminescence resonance energy transfer

A novel immunosensor for the detection of squamous cell carcinoma antigen (SCCA) based on magnetic nanoparticles and electrochemiluminescence resonance energy transfer in CdTe@Carbon dots (CdTe@CDs) is presented. First, Fe3O4 magnetic nanoparticles were synthesized as a solid support for the primary antibody. A sandwich-type immunoassay was performed on a magnetic force controlled carbon paste electrode via immunoreaction among the CdTe@CDs-labeled secondary antibody, SCCA, and primary antibody on the surface of the magnetic nanoparticles. A CdTe@CDs on the CdTe@CDs-labeled secondary antibody generated luminescence upon electrochemical oxidation, and great signal amplification was achieved because the CDs transferred energy to CdTe. The system was optimized to realize reliable determination of SCCA concentration within the range 0.02-12 ng/mL with a detection limit of 6.3 fg/mL (S/N = 3). (C) 2014 Elsevier B.V. All rights reserved.