A Dual-Response Quantum Dot Biosensor for Viral Protease and Nucleic Acid Detection

The ongoing circulation of SARS-CoV-2 and seasonal influenza viruses poses significant diagnostic challenges due to overlapping clinical symptoms and the risk of coinfections. Current detection methods, such as RT-qPCR and immunoassays, face limitations, including time-consuming protocols, the inability to differentiate viable viruses, and poor suitability for <i>in vivo</i> imaging. To address this, we developed a quantum dot-based Förster resonance energy transfer (FRET) biosensor (QDB) for the simultaneous detection of SARS-CoV-2 and influenza viruses. The biosensor exploits the specific cleavage of the SARS-CoV-2 main protease and the recognition of influenza viral RNA to produce distinct fluorescence signals. The dual-response biosensor offers rapid response, high specificity, membrane permeability, and biocompatible detection, supporting both <i>in vitro</i> detection and potential <i>in vivo</i> imaging. By modifying the recognition elements, this platform is readily adaptable for multiplexed detection of diverse pathogens, offering significant potential for clinical diagnostics and therapeutic guidance.