Europium nanoparticle-based immunoassays for sensitive detection of pathogens

We describe and review the application of europium (Eu(3+)) nanoparticle (NP)-based immunoassays (ENIA) for rapid, sensitive, and quantitative detection of pathogens through antibody-antigen recognition. The extremely intense luminescence of the NPs can be directly detected without the need for enzymatic signal amplification or sample preparation. Incorporation of biotinylated anti-streptavidin (SA) and SA-coated Eu(3+) molecules or tyramide molecules for signal amplification (TSA) results in enhanced signal intensity, and further improves detection sensitivity of ENIAs. Our studies demonstrate that ENIA provides a highly specific, ultrasensitive and relatively simple format for detection of HIV-1 p24 antigen, anthrax toxin, and F1 factor and LcrV antigen of Y. pestis., and has the potential for broad application in clinical diagnosis and laboratory research.