Ultrabright PCNs@Coumarin 6-Enhanced Wireless Lateral Flow Immunoassay Platform for Ultrasensitive Detection of...

Porphyromonas gingivalis (Pg), a keystone pathogen of periodontal disease, is associated with multiple systemic diseases. However, traditional methods have core bottlenecks, such as low sensitivity, long detection times, complex procedures, and expensive equipment. In this study, an ultrasensitive wireless lateral flow immunoassay platform (WLFIAP) was developed based on the deep integration of fluorescent nano-DNA walker-microelectronics technology. A novel fluorescent metal-organic framework (porous coordination network@coumarin 6 nanocomposites, PCNP6) was synthesized, which showed ∼16.95-fold higher fluorescence intensity than commercial PCNs and had a significantly prolonged fluorescence lifetime. The quadruped DNA walker with excellent locomotion dynamics and continuity further amplified the fluorescence signal through Mg2+-dependent DNAzyme activity. Relying on a self-developed wireless LFIA analyzer for fast and accurate interpretation of test strips, the WLFIAP achieved a wide linear detection range for Pg (8-8 × 107 CFU/mL) with a limit of detection as low as 5 CFU/mL. Validation using 29 clinical saliva samples confirmed that the WLFIAP has excellent accuracy and strong anti-interference capability, while being significantly less costly and more operationally convenient than polymerase chain reaction. In conclusion, the WLFIAP serves as a powerful and versatile platform for point-of-care testing (POCT) of Pg, supporting chair-side diagnosis, at-home self-testing, and large-scale community screenings.