Immunosorbent assay based on upconversion nanoparticles controllable assembly for simultaneous detection of three antibiotics.

The abuse of antibiotics leads to an increase in resistant strains, which in turn leads to the development of superbugs that pose great difficulties for the treatment of human diseases. A high-throughput and highly sensitive avidin biotin complex immunosorbent assay based on upconversion nanoparticles controllable assembly (ABC-ULISA) for the detection of antibiotics was developed, which enabled accurate quantitative detection in a shorter period of time. Streptavidin and biotin-labeled upconversion nanoparticles form avidin-biotin-upconversion complex, which was then combined with biotinylated antibody to achieve double amplification of the signal, further improving detection sensitivity. Upconversion nanoparticles with 808 nm excitation provide better penetration without the need for an external source. The 96-well enzyme-linked plate was used as a detection platform to meet the high-throughput needs. ABC-ULISA was used to simultaneously detect three antibiotics with a limit of detection of 0.15 ng/mL for sulfamethazine, 0.03 ng/mL for sarafloxacin, and 0.05 ng/mL for tetracycline. The detection limit of ABC-ULISA was much lower than the traditional ELISA and ordinary ULISA. Moreover, ABC-ULISA was also versatile, and the corresponding target can be detected by changing different antibodies. The results were stable and reliable, and the equipment could be miniaturized, which was expected to be commercialized and on-site.