Abstract
We revealed that 100% injection of solute molecules regardless of solute charges from micro to nanochannel, where the electrostatic interaction is dominant, is achieved utilizing MPa pressure-driven flow. Different injection rates depending on solute charges could be cancelled by the fluid drag on solute molecules. The results in this study provide important knowledge for conceptual design of nanofluidic devices for fL-analytical applications such as single cell/single molecule analysis.