A laser-induced breakdown spectroscopy-integrated lateral flow strip (LIBS-LFS) sensor for rapid detection of pathogen

Incorporation of new readout methods with established analytical devices allows methodological innovations in analytical sciences. Herein, we present a new sensing platform by combining an ultrasensitive element analyzer, namely the laser-induced breakdown spectroscopy (LIBS) and a lateral flow strip (LFS). Ag x Au y bimetallic nanoparticles (Ag x Au y BNPs) are selected as the labels to deliver the optimal quantitative performance by analyzing the Ag (I) signal from the test (T) line of LFS. For prototypical application in pathogen detection , the LIBS-LFS sensor can achieve a detection limit of 1.6 cfu mL −1 of Staphylococcus aureus ( S. aureus ) within 10 min, which is superior to conventional methods. Importantly, the signals of Ag x Au y BNPs for visual and LIBS analysis are stable and still readable after the detection is finished and the test strip is stored for up to 13 days, suggesting a potential for long-term data preservation. This combination of LIBS with LFS provides a new concept toward integrated nano/analytical devices that can benefit various application scenarios.