Novel Electrochemiluminescence-Sensing Platform for the Precise Analysis of Multiple Latent Tuberculosis Infection...

Latent tuberculosis infection (LTBI) is one of the major contributing factors for the high incidence of tuberculosis, and the low contents of LTBI markers in human serum present a great challenge for the diagnosis of LTBI. Here, we reported a novel electrochemiluminescence (ECL)-sensing platform for the precise analysis of multiple LTBI markers, interferon-gamma (IFN-γ) and interleukin (IL)-2. In this approach, self-prepared carbon quantum dots (CQDs) and luminol were integrated onto gold nanoparticles (AuNPs), which were further enriched on the surface of magnetic bead (MB) to create two solid-phase ECL nanoprobes (MB@Au@CQDs and MB@Au@luminol) for improving the detection sensitivity efficiently. Graphene oxide (GO) and AuNPs were electrodeposited onto a patterned indium tin oxide (ITO) electrode with two spatially resolved areas in sequence to form two sensitive and stable sensing areas. IFN-γ-antibody (Ab)₁ and IL-2-Ab₁ were separately immobilized on the two sensing areas to capture the corresponding LTBI markers, which were further recognized by IFN-γ-Ab₂ and IL-2-Ab₂ labeled as MB@Au@CQDs and MB@Au@luminol. The ECL intensity depended linearly on the content of IFN-γ and IL-2 in the range of 0.01-1000 pg mL^-1, with a low detection limit of 10 fg mL^-1. The proposed ECL-sensing platform is simple, sensitive, accurate, reliable, and specific to the detection of rare IFN-γ and IL-2 in human serum and provides a valuable protocol for facilitating fast and precise diagnosis of LTBI.