An ultra-sensitive and point-of-care time-resolved fluorescence immunochromatographic platform for trace-level brucellosis antibody rapid on-site detection.

Brucellosis, a significant zoonotic disease, poses a threat to the animal husbandry industry as well as human health. To facilitate rapid and highly sensitive on-site brucellosis diagnostics, we have devised a time-resolved fluorescence immunochromatographic test strip (TRFICTS). TRFICTS employs time-resolved fluorescent microspheres (TRFMs) as both signal amplifiers and label reporters, achieving a sensitivity that is at least 12,800 times greater than the rose Bengal plate test (RBT) recommended by the World Organization for Animal Health (WOAH). TRFICTS reaches a trace-level sensitivity with a detection limit of 0.048 IU/mL, making it suitable for detecting trace antibodies produced during the early stages of brucellosis infection. Furthermore, TRFICTS allows for detection at room temperature using 30 min through simple procedures, and a portable TRFICTS reader has been developed to automate the quantification of fluorescence signals for brucellosis diagnostics. Proven through practical applications, TRFICTS demonstrates high sensitivity, specificity, accuracy, and repeatability. Therefore, TRFICTS represents a promising tool for epidemiologic surveillance and brucellosis management.