Ratiometric Dual-Response Quantum Dot Spherical Nucleic Acid for Monitoring Viral Secondary Bacterial Infections

Viral-bacterial coinfections present intricate pathologies that exacerbate disease progression and elevate mortality rates. Understanding the dynamic interplay between viruses and bacteria during coinfection is critical for developing effective therapeutic interventions. However, current diagnostic tools primarily rely on static detection methods, limiting their ability to monitor real-time infection dynamics. Here, we introduce a ratiometric, dual-responsive quantum dot spherical nucleic acid (QD-SNA) probe capable of simultaneously detecting viral- and bacterial-specific markers in vivo. This probe enables real-time monitoring of coinfections, as demonstrated in a mouse model of influenza virus (H1N1) and methicillin-resistant Staphylococcus aureus infection. By providing dynamic, visual insights into the coinfection process, the QD-SNA probe holds significant potential for preclinical drug screening and the diagnosis of respiratory pathogen infections.