A Simple Cost-Effective Method to Fabricate Single Nanochannels by Embedding Electrospun Polyethylene Oxide Nanofibers

Abstract

Solid state nanochannels provide significant practical advantages in many fields due to their interesting properties, such as controllable shape and size, robustness, ion selectivity. But their complex preparation processes severely limit their application. In this study, a simple cost-effective method to fabricate single nanochannel by embedding a single polyethylene oxide (PEO) nanofiber is presented. Firstly, PEO nanofibers are prepared by electrospinning, and then a single PEO nanofiber are precisely transferred to the target sample using a micromanipulation platform. Then, PDMS is used for embedding, and finally, the PEO nanofiber is dissolved to obtain a single nanochannel. Unlike other methods of preparing nanochannels by embedding nanofibers, this method can prepare single nanochannel. The diameter of nanochannel can be as fine as 100 nm, and the length can reach several micrometers. The power generation between two potassium chloride solutions with various combinations of concentrations was investigated using the nanochannel. This low-cost flexible nanochannel can also be used in various applications, including DNA sequencing and biomimetic ion channel.

Keywords: PDMS nanochannel; electrospinning; polyethylene oxide nanofiber; power generation.

Figure 1

Schematic diagram of PEO nanofibers electrospinning setup. The inset picture is a high‐resolution SEM image of the PEO nanofibers.

Figure 2

Process of the single nanochannel fabrication: a) Preparing two tape patterns on glass slide; the gap is approximately 200 μm. b) Transferring a single PEO fibre on the two patterns with the help of a home built micromanipulator. c) Covering the PEO fibre with PDMS. d) Dissolving the PEO fibre after the PDMS is solidified. e) Finally, bonding the nanochannel with glass slides and drilling two holes as solution reservoirs. f) An optical image of the obtained single PDMS nanochannel device.

Figure 3

a) Photo of home built micromanipulator. b) The microscopic image of the nanoprobe and the PEO nanofiber focused together. c) A single PEO nanofiber suspended on the two tapes with a spacing of 200 μm. d) A high resolution SEM image of the suspended single PEO nanofiber.

Figure 4

Fluorescence image of single nanochannels filling with a solution of the fluorescent dye fluorescein. Panels a‐f show the process of the fluorescein solution slowly diffusing from one side to the other side of the nanochannel.

Figure 5

Experimental setup for nanochannel conductivity measurement: a) Schematic of the ionic current measurement. b) I–V curves of the PDMS nanochannel at different KCl concentrations.

Figure 6

Single PDMS nanochannel power generator. a) I–V curve for different KCl concentration gradients. b) The osmotic voltage generated from the single PDMS nanochannel with various concentration gradient. c) The osmotic current generated from the single PDMS nanochannel. d) Dependence of the maximum power output density on the concentration gradient of the single PDMS nanochannel .