The SARS-CoV-2 pandemic caused a public health crisis throughout the world and highlighted the need for rapid and sensitive testing as a countermeasure. A sensitive and specific biosensor platform is developed for the detection of antigen and RNA of SARS-CoV-2, and its variant (B1.1.529). The demonstrated biosensor platform combines unique protein catalyzed capture bioreceptors (PCCs) for antigen capture and a chimeric (RNA-DNA) probe for RNA detection using LwaCas13a collateral cleavage activity atop graphene field effect transistors (gFETs). The reported biosensor is able to differentiate unprocessed 104 pfu m−1 samples of SARS-CoV-2 from Influenza and Rhinovirus. The limit of detection (LOD) calculated for SARS-CoV-2 antigen is 103 in buffer and 104 PFU mL−1 in 10% saliva, while LOD of ≈65 am calculated for viral RNA isolate without amplification. To provide a high reliability of detection, the role of internal and external factors with respect to gate voltage is further analyzed by Principal Component Analysis (PCA). Based on PCA analysis, the authors are able to classify the samples as pathogen positive or negative (Y > 0: Positive for pathogen, Y < 0: Negative for pathogen). The reported platform can be quickly adapted for multi-omics and multiplexed diagnosis of continuously evolving biothreats and global pandemics.
Link to full article in Advanced Materials Technology: https://onlinelibrary.wiley.com/doi/10.1002/admt.202201945