Monolayer WS<sub>2</sub> Nanopores for DNA Translocation with Light-Adjustable Sizes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28125779.
- Also identified by DOI 10.1021/acsnano.6b08028 and PMC identifier 5893941.
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Abstract
Two-dimensional materials are promising for a range of applications, as well as testbeds for probing the physics of low-dimensional systems. Tungsten disulfide (WS<sub>2</sub>) monolayers exhibit a direct band gap and strong photoluminescence (PL) in the visible range, opening possibilities for advanced optoelectronic applications. Here, we report the realization of two-dimensional nanometer-size pores in suspended monolayer WS<sub>2</sub> membranes, allowing for electrical and optical response in ionic current measurements. A focused electron beam was used to fabricate nanopores in WS<sub>2</sub> membranes suspended on silicon-based chips and characterized using PL spectroscopy and aberration-corrected high-resolution scanning transmission electron microscopy. It was observed that the PL intensity of suspended WS<sub>2</sub> monolayers is ∼10-15 times stronger when compared to that of substrate-supported monolayers, and low-dose scanning transmission electron microscope viewing and drilling preserves the PL signal of WS<sub>2</sub> around the pore. We establish that such nanopores allow ionic conductance and DNA translocations. We also demonstrate that under low-power laser illumination in solution, WS<sub>2</sub> nanopores grow slowly in size at an effective rate of ∼0.2-0.4 nm/s, thus allowing for atomically controlled nanopore size using short light pulses.
Medical subject headings
- DNA
- Disulfides
- Light
- Nanopores
- Tungsten