TA-TaTe2@lysozyme-based smartphone-integrated lateral flow biosensor for colorimetric and photothermal dual-mode bacterial label-free detection

Lateral flow biosensors (LFBs) have long been used for rapid detection of various biological targets, including bacteria. However, antibody sandwich-based colorimetric LFBs often face limitations due to low sensitivity of quantitative analysis and complicated antibody labeling, which hampers their widespread adoption for point-of-care testing (POCT) of bacteria. To address these challenges, we prepared TA-TaTe2@lysozyme nanocomposites based on TaTe2 nanosheets and developed a colorimetric/photothermal dual-mode LFB for sensitive, portable, and label-free detection of S. aureus. Due to the high optical absorption and photothermal conversion efficiency of TA-TaTe2@lysozyme, the photothermal detection limit of the LFB is 93 CFU mL-1, which is 68 times more sensitive than colorimetric detection. Based on the bacterial capture ability of TA-TaTe2@lysozyme, we proposed a label-free detection strategy that does not require antibody labeling to simplify the process and reduce costs. Moreover, the smartphone-integrated LFB enables portable result readout and analysis in both colorimetric and photothermal dual modes, improving detection accuracy. This promising bacterial POCT method may facilitate food safety and healthcare monitoring.