High-Voltage Biomolecular Sensing Using a Bacteriophage Portal Protein Covalently Immobilized Within a Solid-State Nanopore
The application of nanopores as label-free, single-molecule biosensors for electrical or optical probing of structural features in biomolecules has been widely explored. While biological nanopores (membrane proteins and bacteriophage portal proteins) and solid-state nanopores (thin films and two-dimensional materials) have been extensively employed, the third class of nanopores known as hybrid nanopores, where an artificial membrane substitutes the organic support membrane of proteins, has been only sparsely studied, due to challenges in implementation. G20c portal protein contains a natural DNA pore that is used by viruses for filling their capsid with viral genomic DNA. We have previously developed a lipid-free hybrid nanopore by "corking" the G20c portal protein into a SiNx nanopore. Herein, we demonstrate that through chemical functionalization of the synthetic nanopore, covalent linkage between the solid-state pore and the G20c portal protein considerably improves the hybrid pore stability, lifetime, and voltage resilience. Moreover, we demonstrate electric-field-driven and motor protein-mediated transport of DNA molecules through this hybrid pore. Our integrated protein/solid-state hybrid nanopore can serve as a robust and durable framework for sensing and sequencing at high voltages, potentially providing higher resolution, higher signal-to-noise ratio, and higher throughput compared to the more conventional membrane-embedded protein platforms.