Ultrasensitive electrochemiluminescence immunoassay for simultaneous determination of CA125 and CA15-3 tumor markers based on PAMAM-sulfanilic acid-Ru(bpy)3 2+ and PAMAM-CdTe@CdS nanocomposite

摘要

Abstract A multiplex ultrasensitive electrochemiluminescence (ECL) immunoassay was developed for the simultaneous determination of two different tumor markers, cancer antigen 153 (CA 15-3) and cancer antigen 125 (CA 125) using polyamidoamine dendrimer-quantum dots (PAMAM-QDs) and PAMAM-sulfanilic acid-Ru(bpy)3 2+ as the signal probes and Fe3O4–SiO2 as a magnetic bead. The CdTe@CdS- QDs and Ru(bpy)3 2+ at the presence of tripropyl amine (TPA) as coreactant generate ECL at an applied voltage of + 1.2V (vs Ag/AgCl) in two different wavelengths 500 and 620nm, respectively. Based on this strategy, the simultaneous detection of two tumor markers in single run carried out. This dual signal amplification technique was achieved by employing Fe3O4@SiO2-dendrimer as immunosensing platform and PAMAM as the carrier for immobilizing CdTe@CdS and Ru(bpy)3 2+ probes. Experimental results illustrated that the designed immunosensor can be used to sequentially detection of CA 125 and CA 15-3 markers with the wide linear ranges of 1μU/mL to 1U/mL and 0.1mU/mL to 100U/mL with very low detection limits of 0.1μU/mL and 10μU/mL, respectively. The application