Controlled gating and electrical detection of single 50S ribosomal subunits through a solid-state nanopore in a microfluidic chip

We describe analysis and control of 50S ribosomal subunits by a solid-state 45 nm diameter nanopore incorporated in a microfluidic chip. When used as a resistive pulse sensor, translocation of single 50S subunits through the nanopore produces current blockades that have a linear dependence on applied voltage. Introduction of individual subunits into the fluidic channel shows a threshold behavior that allows controlled entry of individual 50S ribosomal subunits. The incorporation of nanopores into a larger optofluidic chip system opens possibilities for electrical and optical studies of single ribosomes in well-defined and rapidly variable chemical environments.