Fabrication of nanopores with ultrashort single-walled carbon nanotubes inserted in a lipid bilayer

Abstract

We describe a protocol for the insertion of ultrashort single-walled carbon nanotubes (SWCNTs) to form nanopores in a Montal-Mueller lipid bilayer. The SWCNTs are designed to bind to a specific analyte of interest; binding will result in the reduction of current in single-channel recording experiments. The first stage of the PROCEDURE is to cut and separate the SWCNTs. We cut long, purified SWCNTs with sonication in concentrated sulfuric acid/nitric acid (3/1). Isolation of ultrashort SWCNTs is carried out by size-exclusion HPLC separation. The second stage is to insert these short SWCNTs into the lipid bilayer. This step requires a microinjection probe made from a glass capillary. The setup for protein nanopore research can be adopted for the single-channel recording experiments without any special treatment. The obtained current traces are of very high quality, showing stable baselines and little background noise. Example procedures are shown for investigating ion transport and DNA translocation through these SWCNT nanopores. This nanopore has potential applications in molecular sensing, nanopore DNA sequencing and early disease diagnosis. For example, we have selectively detected modified 5-hydroxymethylcytosine in single-stranded DNA (ssDNA), which may have implications in screening specific genomic DNA sequences. The protocol takes ∼15 d, including SWCNT purification, cutting and separation, as well as the formation of SWCNT nanopores for DNA analyses.

DNA‐Based Nanopore Sensing

“…[57] Furthermore,n ew nanopores made in different materials also hold the potential in DNArelated sensing. [12] Second, new types of DNA-based sensing applications should be developed. We have summarized six types of applications here,but obviously there are many more to be expected such as nucleic acid logic circuits, [58] screening of drug molecules, [59] and discrimination between enantiomers of chiral molecules.…”

“…[11] During the past several years,t here has been ab urst of new nanopores made in different materials. [12] All the new pores are expected to be employed for nanopore sensing in the coming decades.…”

Biomimetic Solid-State Nanochannels: From Fundamental Research to Practical Applications

“…Similarly, the solid‐state nanochannel also can be inserted into biological molecules. Wu et al described a protocol for the insertion of ultrashort single‐walled carbon nanotubes (SWCNTs) to form nanopores in a lipid bilayer. To the solid‐state nanomaterials, recent investigation progress concerning heterogeneous membranes has also been achieved utilizing inorganic and organic materials such as silicon dioxide, titanium dioxide, and hydrogels.…”

“…Similarly, the solidstate nanochannel also can be inserted into biological molecules. Wu et al [ 58 ] described a protocol for the insertion of ultrashort single-walled carbon nanotubes (SWCNTs) to small 2016, 12, No. 21, 2810-2831 form nanopores in a lipid bilayer.…”

DNA‐basierte Nanoporensensorik

“…In Kombination mit einer Oberflächenmodifizierung der Porenwand haben Festkörpernanoporen das Potential, vielfältige Analyten zu detektieren . In den letzten Jahren ist die Zahl neuer Nanoporen in verschiedenen Materialien sehr rasch gewachsen . Sie alle dürften in den nächsten Jahrzehnten Anwendung in der Nanoporensensorik finden.…”