An ultra-sensitive photothermal lateral flow immunoassay for 17?-estradiol in food samples

Hormone residues in food and drinking water endanger human health, therefore, on-site analysis techniques of superior performance are important for monitoring this risk. In this study, an ultra-sensitive photothermal lateral flow immunoassay (LFIA) for quantification of 17 beta-estradiol (E2) has been developed. Anti-E2 antibody modified black phosphorus-Au (BP-Au) nanocomposite was developed as a photothermal contrast signal probe and the temperature at test-zone was recorded with an infrared camera. Under the irradiation of 808 nm laser at testzone, it gave temperatures negatively related to the concentrations of E2 in samples. Under optimal detecting conditions, the developed photothermal LFIA exhibited a limit of detection of 50 pg mL-1, over 100-fold more sensitive than visual LFIA, and a linear range of 3 orders of magnitude. This method has been successfully applied to water, milk, and milk powder samples.

Automated summary

In this study, an ultra-sensitive photothermal lateral flow immunoassay (LFIA) was developed for quantification of 17beta-estradiol (E2) in food and drinking water. The developed method demonstrated sensitivity over 100-fold higher than visual LFIA and a linear range of 3 orders of magnitude.