Spectrum-based and color-selective electrochemiluminescence immunoassay for determining human prostate specific antigen in near-infrared region.

Abstract The conventional electrochemiluminescence (ECL) analyses were performed via detecting the time (or potential) dependent ECL intensity with the proceeding of ECL reaction. Herein, by spectrally recording all the photons generated in ECL process, a spectral ECL immunoassay was developed in near-infrared (NIR) region with human prostate specific antigen (PSA) as target and dual-stabilizers-capped CdTe nanocrystals (NCs) as tags. The CdTe NCs displayed efficient ECL around 780 nm with the full width at half-maximum around 70 nm in the immune-complexes, the maximum intensity on ECL spectrum profiles increased linearly with the logarithmic increased concentration of PSA from 20.0 fg/mL to 100.0 pg/mL, indicating a sensitive and color-selective ECL immunoassay in NIR region with improved anti-interference performance to biological autofluorescence and tissue absorption. The spectral ECL immunoassay in NIR region might provide an important technique support for developing color-selective ECL assay of different wavebands.