Lanthanide-doped luminescent lateral flow immunoassay for ultrasensitive and quick detection of methyltestosterone in fish samples

Hormones residual especially in aquatic products has become a serious threat to food safety. The development of sensitive, affordable, on-site, quick detection methods for hormones residual still faces great challenges. Herein, taken methyltestosterone (MT) as a representative analyte, a competitive lateral flow immunoassay (LFIA) platform was constructed using ultrabright lanthanide-doped luminescent nanoparticles i.e. YVO4: Eu as the label probes. The YVO4: Eu NPs were obtained by a facile hydrothermal method using lanthanide ions, sodium orthovanadate, and polyacrylic acid, as the precursor and surface modifier, respectively. Thanks to the advantages of high fluorescence quantum yield, abundant surface functional groups, good dispersity and water-solubility, the harvested YVO4: Eu NPs would be a competitive and promising label probe in LFIA. The YVO4: Eu LFIA test strips have shown a detection limit i.e. 0.1 ng/mL, which was about 1 or 2 orders of magnitude lower than most reported methods. Furthermore, the proposed test strips were successfully applied for the quantitative, accurate, and quick screening of MT in fish samples. This work reported a competitive luminescent label probe for food safety and quality control.