Write–Read 3D Patterning with a Dual-Channel Nanopipette

Abstract

Nanopipettes are becoming extremely versatile and powerful tools in nanoscience for a wide variety of applications from imaging to nanoscale sensing. Herein, the capabilities of nanopipettes to build complex free-standing three-dimensional (3D) nanostructures are demonstrated using a simple double-barrel nanopipette device. Electrochemical control of ionic fluxes enables highly localized delivery of precursor species from one channel and simultaneous (dynamic and responsive) ion conductance probe-to-substrate distance feedback with the other for reliable high-quality patterning. Nanopipettes with 30-50 nm tip opening dimensions of each channel allowed confinement of ionic fluxes for the fabrication of high aspect ratio copper pillar, zigzag, and Γ-like structures, as well as permitted the subsequent topographical mapping of the patterned features with the same nanopipette probe as used for nanostructure engineering. This approach offers versatility and robustness for high-resolution 3D "printing" (writing) and read-out at the nanoscale.

A Multiparameter pH‐Sensitive Nanodevice Based on Plasmonic Nanopores

“…As a result, we can read out molecular information through the nano pipette. [14] Many efforts have been made to modify the nanoorifice of the nanopipette to explore the chemical environment in single cells. [15] Özel and co-workers functionalized nanopipettes as glucose nanosensors by immobilizing glucose oxidase covalently to the tip.…”

Nanopore Sensing

“…239 For patterning, the probe is brought into close proximity with the underlying Au substrate surface and a delivery potential is applied to the precursor-containing barrel to drive out copper ions. Next, as the Cu deposition process starts (prompted by the substrate potential) and the deposited feature grows in the confined region under the nanopore orifice of the probe, a slow retraction of the nanopipette takes place due to the positional feedback of SICM.…”

Differential-Concentration Scanning Ion Conductance Microscopy

“…As part of these simulations, we also assess the importance of EOF in the SICM response. Previous studies have considered EOF to not significantly influence the response of nanopipettes and the SICM response, under a range of conditions, 22,35,36 and it can be advantageous to ignore due to computational expense.…”