A reliable and robust direct screening methodology based on a quantum dot (QD) fluorescent immunoassay has been developed to detect trace levels of different antibiotic species from the family of the tetracyclines (e.g. oxytetracycline, tetracycline, chlortetracycline and doxycycline) in contaminated bovine muscle tissues. First, the synthesis and characterization of a new immunoprobe (oxytetracycline-bovine serum albumin-QD) has been carried out for its further application in the development of a competitive fluorescent QD-immunoassay. The here-developed fluoroimmunoassay provides sensitive and binary "yes/no" responses being appropriate for the screening of this family of antibiotics above or below a pre-set concentration threshold. The detection limit achieved with this strategy, 1 µg/L in aqueous media and 10 µg/kg in bovine muscle samples, is 10-fold lower than the maximum level concentration allowed by International Legislation in muscle tissue, enabling suitable and efficient screening of the antibiotics.