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). AgAu bimetallic nanoparticles (AgAuBNPs) 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 of Staphylococcus aureus (S. aureus) within 10 min, which is superior to conventional methods. Importantly, the signals of AgAuBNPs 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.