Ultrasensitive Detection of Staphylococcus aureus Based on Photonic Crystal Microsphere Suspension Array-Assisted Loop-Mediated Isothermal Amplification

The development of high-throughput, sensitive and portable strategies for detecting foodborne pathogens is urgently needed in food safety, especially during an outbreak. Herein, an ultrasensitive suspension array was constructed by designing photonic crystal microsphere (PCM)-assisted loop-mediated isothermal amplification (LAMP) for Staphylococcus aureus detection. The PCM-LAMP suspension array integrated the optical signal enhancement capability of the biomimetic microporous three-dimensional PCM surface with the thousand-fold signal amplification of LAMP. The biomimetic PCMs displayed a periodic dielectric nanostructure and enhanced the fluorescence intensity of the LAMP reaction, leading to high sensitivity. The PCM-LAMP suspension array allowed sensitive detection of the target DNA of S. aureus without long-term culture. Under optimal conditions, the limit of detection for S. aureus genomic DNA reached as low as 0.18 fM, and the assay exhibited excellent specificity against other bacteria. Furthermore, trace target DNA in food samples was accurately quantified, demonstrating its potential for practical applications. Therefore, the developed PCM-LAMP suspension array holds great promise for ultrasensitive and rapid detection of foodborne pathogens.