SEM-induced shrinking of solid-state nanopores for single molecule detection

Prabhu, Anmiv S.; Freedman, Kevin J.; Robertson, Joseph W. F.; Nikolov, Zhorro; Kasianowicz, John J.; Kim, Min Jun

doi:10.1088/0957-4484/22/42/425302

Cited by 44 publications

(39 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In other words, detecting 1 μm particles or microorganisms such as bacteria requires a 2–3 μm diameter pore. Solitary pores with micro or nanoscale diameters used in solid‐state resistive pulse sensors can be easily fabricated using top‐down fabrication methods employing focused ion or electron beams . Along with the pore diameter, pore length also influences the detection resolution.…”

Section: Introductionmentioning

confidence: 99%

Low aspect ratio micropores for single‐particle and single‐cell analysis

et al. 2015

Self Cite

View full text Add to dashboard Cite

This paper describes microparticle and bacterial translocation studies using low aspect ratio solid-state micropores. Micropores, 5 μm in diameter, were fabricated in 200 nm thick free-standing silicon nitride membranes, resulting in pores with an extremely low aspect ratio, nominally 0.04. For microparticle translocation experiments, sulfonated polystyrene microparticles and magnetic microbeads in size range of 1-4 μm were used. Using the microparticle translocation characteristics, we find that particle translocations result in a change only in the pore's geometrical resistance while the access resistance remains constant. Furthermore, we demonstrate the ability of our micropore to probe high-resolution shape information of translocating analytes using concatenated magnetic microspheres. Distinct current drop peaks were observed for each microsphere of the multibead architecture. For bacterial translocation experiments, nonflagellated Escherichia coli (strain HCB 5) and wild type flagellated Salmonella typhimurium (strain SJW1103) were used. Distinct current signatures for the two bacteria were obtained and this difference in translocation behavior was attributed to different surface protein distributions on the bacteria. Our findings may help in developing low aspect ratio pores for high-resolution microparticle characterization and single-cell analysis.

show abstract

Section: Introductionmentioning

confidence: 99%

Low aspect ratio micropores for single‐particle and single‐cell analysis

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Despite this limitation, the transition from one setup to the other is quick and straightforward. In comparison with existing techniques for controlling nanopore size such as the use of SEM 5 , thermal oxidation and membrane reshaping 8 , high electric fields offer a faster, more precise and less expensive methodology that can be performed on the lab bench using standard equipment and provide a broader range of nanopore sizes. The ability to rapidly and reproducibly reduce low-frequency noise also makes initial fabrication more reliable and prolongs the lifetime of solid-state nanopores, as previously used pores can be rejuvenated for further experiments.…”

Section: Figure 3amentioning

confidence: 99%

“…However, the creation of a nanopore in a thin insulating membrane remains challenging. Fabrication methods involving specialized focused electron beam systems can produce well-defined nanopores, but yield of reliable and low-noise nanopores in commercially available membranes remains low 2,3 and size control is nontrivial 4,5 . Here, the application of high electric fields to fine-tune the size of the nanopore while ensuring optimal low-noise performance is demonstrated.…”

Section: Introductionmentioning

confidence: 99%

“…While control of nanopore size is possible, it is typically expensive and laborious to achieve, requiring specialized equipment and skilled personnel. For example, nanopores drilled by focused-ion beam have been recently shown to shrink under specific experimental conditions in a scanning electron microscope (SEM) 5 . In other approaches, nanopores drilled by transmission electron microscopy (TEM) can expand or shrink depending on the beam conditions and subsequent exposure to aqueous solvents 8 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores

Beamish

Kwok

Tabard‐Cossa

et al. 2013

JoVE

View full text Add to dashboard Cite

Solid-state nanopores have emerged as a versatile tool for the characterization of single biomolecules such as nucleic acids and proteins 1 . However, the creation of a nanopore in a thin insulating membrane remains challenging. Fabrication methods involving specialized focused electron beam systems can produce well-defined nanopores, but yield of reliable and low-noise nanopores in commercially available membranes remains low 2,3 and size control is nontrivial 4,5 . Here, the application of high electric fields to fine-tune the size of the nanopore while ensuring optimal low-noise performance is demonstrated. These short pulses of high electric field are used to produce a pristine electrical signal and allow for enlarging of nanopores with subnanometer precision upon prolonged exposure. This method is performed in situ in an aqueous environment using standard laboratory equipment, improving the yield and reproducibility of solid-state nanopore fabrication.

show abstract

“…The process of nanopore drilling can be undertaken using a focused ion beam [41] for pore sizes >20 nm, or a field-emission transmission electron microscope (TEM) [28] for pore sizes in the range of 1–30 nm. Focused electron beams are capable of direct atomic displacement via “knock-on” collisions [42].…”

Section: Introductionmentioning

confidence: 99%

Substrate Dependent Ad-Atom Migration on Graphene and the Impact on Electron-Beam Sculpting Functional Nanopores

Freedman

Goyal

Ahn

et al. 2017

Sensors

View full text Add to dashboard Cite

The use of atomically thin graphene for molecular sensing has attracted tremendous attention over the years and, in some instances, could displace the use of classical thin films. For nanopore sensing, graphene must be suspended over an aperture so that a single pore can be formed in the free-standing region. Nanopores are typically drilled using an electron beam (e-beam) which is tightly focused until a desired pore size is obtained. E-beam sculpting of graphene however is not just dependent on the ability to displace atoms but also the ability to hinder the migration of ad-atoms on the surface of graphene. Using relatively lower e-beam fluxes from a thermionic electron source, the C-atom knockout rate seems to be comparable to the rate of carbon ad-atom attraction and accumulation at the e-beam/graphene interface (i.e., Rknockout ≈ Raccumulation). Working at this unique regime has allowed the study of carbon ad-atom migration as well as the influence of various substrate materials on e-beam sculpting of graphene. We also show that this information was pivotal to fabricating functional graphene nanopores for studying DNA with increased spatial resolution which is attributed to atomically thin membranes.

show abstract

SEM-induced shrinking of solid-state nanopores for single molecule detection

Cited by 44 publications

References 34 publications

Low aspect ratio micropores for single‐particle and single‐cell analysis

Low aspect ratio micropores for single‐particle and single‐cell analysis

Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores

Substrate Dependent Ad-Atom Migration on Graphene and the Impact on Electron-Beam Sculpting Functional Nanopores

Contact Info

Product

Resources

About