Solid-state Nanopore Fabrication and Sensing Towards Integrated Nucleic Acid Testing

Download or read book Solid-state Nanopore Fabrication and Sensing Towards Integrated Nucleic Acid Testing written by Zifan Tang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Regular, accurate, rapid, and inexpensive self-testing for infectious diseases is urgently needed to optimize clinical care and guide infection control to limit disease spread. Nucleic Acid Amplification Test (NAAT) is the most sensitive and specific method, thus becoming the gold-standard technique for diagnosis. However, laboratory-based NAAT requires highly trained personnel, dedicated facilities, and instrumentations, delaying testing results and limiting testing capacity. Existing self-testing methods usually rely almost exclusively on rapid antigen tests. Typically, the sensitivity of antigen tests is 30% to 40% lower than the nucleic acid amplification testing (NAAT), which could miss a significant portion of infected patients. Therefore, a self-testing NAAT device for diagnosis is strongly needed to optimize clinical care and guide infection control to limit disease spread. This thesis mainly focuses on exploring the possibility of developing a solid-state nanopore-based NAAT device for a new form of ultracompact, rapid, and label-free nucleic acid self-testing. We demonstrated the nucleic acid amplification coupled nanopore counting method for qualitative positive/negative nucleic acid testing. Due to its intrinsic single molecule sensitivity, the nanopore sensor could make a faster positive/negative call than bulk optical methods. To further explore a more reliable and integratable method for nanopore fabrication, we developed the laser-assisted breakdown method for single nanopore fabrication. We theoretically and experimentally demonstrated that combining a high laser power and a low electric field is statistically favorable for forming a single nanopore at a programmed location. Furthermore, we developed a fully integrated sample-in answer-out NAT device for SARS-CoV-2 detection using a self-collected saliva sample. This system can automatically handle the complexity of heat-inactivated sample preparation, pressure-driven sample dispensing, real-time RT-LAMP reaction and detection, and data processing and storage. Using an optical sensor, we achieved a limit of detection (LoD) of 5 virus particles/[mu]l of saliva sample in 45 minutes. The final amplicons from the developed prototype were also detected by nanopore counting methods. Therefore, the successful completion of this project will pave the way for ultracompact, rapid, and affordable nanopore-based nucleic acid testing.