Nanoscale porphyrinic metal-organic frameworks as a photodynamic probe for highly sensitive detection of SARS-CoV-2 related RNA

The outbreak of various epidemics has caused a significant impact on public health. Developing highly efficient techniques for the early detection of pathogenic viruses, e.g., Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is the key to fast screening and diagnosis of patients. Here, a novel detection method with high sensitivity is developed to detect viral nucleic acids by employing nanoscale porphyrinic metal-organic frameworks (NPMOFs) as a photodynamic probe and magnetite nanoparticles as a trapping agent. Benefiting from the high content of porphyrin molecules as the organic linker with improved performance, NPMOFs exhibit the excellent photodynamic effect, which effectively transport energy to O 2 to produce highly active singlet oxygen ( 1 O 2 ) upon light activation. The presence of target nucleic acids allows the capture of NPMOFs probes with magnetite nanoparticles via gene complementary hybridization, resulting in the fast production of remarkable 1 O 2 based on photodynamic effect, which is utilized to decompose the indicator for signal readout. Results indicate that such method enables the detection of SARS-CoV-2 related RNA in the simulated swabs with the limit of detection (LOD) of 4.94 fM within 30 min, presenting giant potential for simple, sensitive and rapid sensing of viral nucleic acids without RNA amplification treatment. This strategy inaugurates a new direction of nanomaterials for signal transduction in biosensing application.