In recent years, a large number of devices based on organic and biological materials have been developed. To scale-up the production of these systems to industrially acceptable standards, there is a need to develop soft-material stamping approaches with the needed resolution, complexity, and versatility. We have recently developed a DNA-based stamping method (supramolecular nano-stamping, SuNS) that has superior resolution and can print multiple molecules at the same time. A similar technique was independently developed by Crooks and co-workers. Here we show that SuNS can be used to efficiently print DNA features on a polymeric substrate (poly(methyl methacrylate), PMMA) with a 40 nm point resolution and a coverage that exceeds 100 mum2. The stamped PMMA substrate was also used as a master to print on a gold substrate. With PMMA being optically clear and electrically insulating, future applications of SuNS to print DNA micro- and nanoarrays are envisioned.
Nanopores are emerging as very effi cient single-molecule sensors. [ 1 , 2 ] They represent a promising technology in the fi eld of single-molecule, unlabelled DNA sequencing. [ 3 ] The mechanical robustness, nanometer-range precision, and rigidness of synthetic nanopores promise an easier integration into sensing technology when compared to membrane-embedded nanopores. [ 4 ] Synthetic nanopores (2-8 nm in diameter) produced from Si 3 N 4 membranes have found several applications in biophysics, such as characterization of DNA duplexes by electromechanical unzipping, detection of DNA/protein complexes, and characterization of proteins and polymers. [5][6][7][8][9][10][11][12] Due to their stochastic nature, real-time single-molecule monitoring techniques are well suited to reveal molecular interaction mechanisms.Here, the use of functionalized Si 3 N 4 nanopores (3.2-6.5 nm in diameter, 30 and 50 nm in length) for the detection of negatively charged gold nanoparticles from 2.4 to 8.9 nm diameter ( Figure 1 ) is shown. It is possible to detect the surface molecular interactions through ionic current alterations, whether or not the electric-fi eld driven nanoparticle threads through the pore. This simulation work suggests that electrostatic interactions are essential to create the initial nanoparticle-nanopore interaction. Once a nanoparticle is engaged into the nanopore, Brownian motion theory fi ts
A hard x-ray imaging microscope based on a phase zone plate has been developed and tested. The zone plate, with a 5 cm focal length and a 0.2 pm smallest linewidth, was used to image 8 keV x rays from the samples. The imaging microscope can be used to obtain nearly diffraction-limited resolution over the entire imaging field, and its resolution is almost independent of source size and source motions. We have tested such an imaging microscope, and a resolution of about 0.4 pm was obtained. The images were obtained with an exposure time of less than 1 min, for a magnification factor of 30 in the x rays. The x rays were then converted into visible light, and another 7 times magnification were obtained by using a lens system coupled to a charge coupled device camera. The results from the imaging microscope, and possible applications, will be discussed. 0 1995 American Institute of Physics.-1NTRODUCTlON
Articles you may be interested in Electron induced chemical nanolithography with self-assembled monolayersElectron-beam nanolithography, acid diffusion, and chemical kinetics in SAL-601With the minimum feature dimension of integrated circuits ͑ICs͒ shrinking to below 130 nm, the IC industry has to choose one among a number of nonoptical lithography tools. Electron beam direct write or mix-and-match lithography is an attractive choice because of the maturity of the technology and the potential of using the tool for several generations of ICs. The low throughput associated with e-beam direct writing of wafers can be significantly reduced by using chemically amplified resists. Two commercially available negative tone chemically amplified resists, AZPN114 and SAL601, were investigated and compared for their performance in e-beam direct writing of wafers at 150, 100, and sub-50 nm resolutions. A number of factors influencing the throughput issue were evaluated. The latitudes of postexposure bake and postexposure delay were compared. It is found that both resists are of high resolution and high contrast, with the highest resolution, 30 nm, achieved for AZPN114. AZPN114 has higher sensitivity and is more stable during postexposure delay than SAL601 but less stable during postexposure bake. A 6 in. industrial wafer was exposed with AZPN114 at gate level at 150 nm resolution using e-beam lithography and it showed feature uniformity across the entire wafer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.