Channel surface property is a crucial factor that affects capture-to-translocation dynamics of single-particles in solid-state pores. Here, we show that atomically-thin dielectrics can be used to finely tune the pore wall surface potential. We isotopically coated alumina of atomically controlled thickness on a Si3N4 micropore. The surface zeta-potential in a buffer was found to decrease sharply by 1 nm thick deposition that served as a water-permeable ultra-thin sheet to modulate the effective charge density of the Al2O3/Si3N4 multilayer structure. Further thickening of the atomic layer enabled to control the zeta potential with a thickness at 3.4 mV/nm resolution. Accordingly, we observed concomitant enhancement in the capture rate and the translocation speed of negatively charged polymeric particles by virtue of the mitigated electroosmotic back flow in the functionalized pore channel. This simple method is widely applicable for tailoring the surface charge properties of essentially any sensors and devices working in aqueous media.
Keywords: Debye length; atomic layer deposition; electroosmosis; nanopore; surface charge; zeta potential.