Instant detection of goat leather artifacts using europium(III)-based fluorescent immunochromatographic assay strips

Leather artifacts represent a vital part of cultural heritage, embodying centuries of craftsmanship and artistic tradition. Conventional detection methods often suffer from limitations including inadequate accuracy and large sample requirements, hindering non-destructive analysis. To address these challenges, this study targets the leather-specific protein collagen through its characteristic peptide sequence (BLG, "TPEVDKEALEKC"). A specific anti-BLG-goat antibody was developed and conjugated with europium-doped fluorescent microspheres to create a competitive fluorescence immunochromatographic assay (FIA) strip for rapid, on-site species identification of leather. Systematic optimization yielded a sensitive, stable, and reproducible assay with a detection limit (LOD) of 1.0 μg mL^-1 for the target protein. The assay strip provides visually interpretable results within 15 min under handheld portable UV light, enabling the determination of animal origin directly at archaeological sites or in museums. Therefore, this FIA not only enables sensitive microscopic detection of leather artifacts but also shows great promise for on-site analysis at archaeological sites. This method offers a novel and practical solution for protein-based cultural relic analysis.