Researchers present a special silicon nitride nanopore-based sensing device that is designed to provide volume information about tau and tubulin protein molecules and their aggregation states. To create the sensor, the team explored how the proteins change the current and voltage flowing through a nanopore system. An electric voltage drives ions’ flow through the nanopore, and when a charged protein molecule is near, it is also driven into the nanopore and blocks the flow of some ions. This causes the open pore current to drop and provides useful information.