Tiny protein detection using pressure through solid-state nanopores.

Solid-state nanopore is a promising tool to detect proteins and its complexes. Small proteins (sub-35 kDa) translocate very fast which could not be detected by normal patch-clamp recording instrument due to low temporal resolution. We first introduce pressure into protein study and detection. The pressure-derived force, combined with the voltage bias, makes very tiny protein (MW < 6.5 kDa) detection possible. Capture rate for Aprotinin is enhanced five times more than that in traditional voltage-driven method by fine tuning of pressure and voltage. Temporal resolution of Aprotinin detection has improved by decreasing effective driving force. Moreover, we provide potential method to locate the equilibrium range for BSA movement in ionic solution by modulating driving pressure and retard voltage. Our study is of fundamental significance in nanopore research and provides unique platforms to study small proteins and other tiny biomolecules.