Development of a photothermal-sensing microfluidic paper-based analytical chip (PT-Chip) for sensitive quantification of diethylstilbestrol

The continuous intake of diethylstilbestrol (DES) residue seriously threatens the health of consumers, so the rapid and sensitive detection of DES is helpful for timely food safety warning. In this study, a photothermal-sensing microfluidic paper-based analytical chip (PT-Chip) was developed for effectively screening of DES residue in foods. Competitive inhibition immunochromatography was introduced and the composite of black phosphorus nanosheets and gold nanoparticles (BP-Au) was used as signal indicators. Then, the test area was irradiated by an 808 nm laser and the photothermal transduction signal was recorded by a thermal imager to achieve sensitive photothermal detection. The amount of DES was obtained by analyzing the temperature change curve of test area. The PT-Chip can achieve accurate quantification of DES with a detection limit of 0.1 μg/L. And the successful determination of DES in different food samples indicating that the PT-Chip can be used as a promising detection device.