22 research outputs found

    Lipid-bilayer-spanning DNA nanopores with a bifunctional porphyrin anchor

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    Holding tight: An artificial nanopore assembled from DNA oligonucleotides carries porphyrin tags (red), which anchor the nanostructure into the lipid bilayer. The porphyrin moieties also act as fluorescent dyes to aid the microscopic visualization of the DNA nanopore

    DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering.

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    Plasmonic sensors are extremely promising candidates for label-free single-molecule analysis but require exquisite control over the physical arrangement of metallic nanostructures. Here we employ self-assembly based on the DNA origami technique for accurate positioning of individual gold nanoparticles. Our innovative design leads to strong plasmonic coupling between two 40 nm gold nanoparticles reproducibly held with gaps of 3.3 ± 1 nm. This is confirmed through far field scattering measurements on individual dimers which reveal a significant red shift in the plasmonic resonance peaks, consistent with the high dielectric environment due to the surrounding DNA. We use surface-enhanced Raman scattering (SERS) to demonstrate local field enhancements of several orders of magnitude through detection of a small number of dye molecules as well as short single-stranded DNA oligonucleotides. This demonstrates that DNA origami is a powerful tool for the high-yield creation of SERS-active nanoparticle assemblies with reliable sub-5 nm gap sizes

    DNA origami based assembly of gold nanoparticle dimers for surface-enhanced Raman scattering

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    Plasmonic sensors are extremely promising candidates for label-free single-molecule analysis but require exquisite control over the physical arrangement of metallic nanostructures. Here we employ self-assembly based on the DNA origami technique for accurate positioning of individual gold nanoparticles. Our innovative design leads to strong plasmonic coupling between two 40 nm gold nanoparticles reproducibly held with gaps of 3.3 +/- 1 nm. This is confirmed through far field scattering measurements on individual dimers which reveal a significant red shift in the plasmonic resonance peaks, consistent with the high dielectric environment due to the surrounding DNA. We use surface-enhanced Raman scattering (SERS) to demonstrate local field enhancements of several orders of magnitude through detection of a small number of dye molecules as well as short single-stranded DNA oligonucleotides. This demonstrates that DNA origami is a powerful tool for the high-yield creation of SERS-active nanoparticle assemblies with reliable sub-5 nm gap sizes

    Proses Pengolahan dan Kualitas Air Minum di Kompleks Perumahan Karyawan PT. Chevron Pacific Indonesia (PT. CPI) Duri-Riau Tahun 2014

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    Water is one of the important matter after the air, nobody can life without drinking until 4-5 days. Drinking water which is not qualified, can resulting disease or even death. Water treatment can prevents disease and resulting qualified drinking water. PT. Chevron Pacific Indonesia (PT. CPI) is one of the companies which has a water treating plant to makes drinking water from raw water The purpose of this research is to know the process of water treatment, the quality of raw water after treatment and quality of distributed drinking water to employees housing PT. Chevron Pacific Indonesia Duri. This research was descriptive survey using simple random sampling technique with 1102 populations and 30 samples. Data were analyzed descriptively in tabulation and narration. The result of the research showed that the water treatment was using coagulation, floculation, sedimentation and desinfectan process. Based on the analysis of obtaained data, the quality of raw water was qualified, whereas the quality of water which was finish the treatment and the quality of distributed drinking water to employees housing on Maret 2014 were not qualified in one parameter. Most of the respondents have been using water as drinking water. The conclusion of this research is the water treatmen process in PT. Chevron Pacific Indonesia was conventional water treatment (complete water treatment). Overall water quality is good, it is recommended to improve adsorption using activated carbon, renew and re-examine the tools used and provision of information about water quality to water users

    Electroosmotic flow reversal outside glass nanopores.

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    We report observations of a striking reversal in the direction of electroosmotic flow (EOF) outside a conical glass nanopore as a function of salt concentration. At high ionic strengths (>100 mM), we observe EOF in the expected direction as predicted by classical electrokinetic theory, while at low salt concentrations (<1 mM) the direction of the flow is reversed. The critical crossover salt concentration depends on the pore diameter. Finite-element simulations indicate a competition between the EOF generated from the inner and outer walls of the pore, which drives flows in opposite directions. We have developed a simple analytical model which reveals that, as the salt concentration is reduced, the flow rates inside the pore are geometrically constrained, whereas there is no such limit for flows outside the pore. This model captures all of the essential physics of the system and explains the observed data, highlighting the key role the external environment plays in determining the overall electroosmotic behavior

    Mechanopathology of Mycobacterium tuberculosis biofilm-like cords

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    &lt;p&gt;RNA-seq raw data, code for QuSAGE analysis of RNA-seq data, and code for agent-based simulation model for the manuscript entitled &#39;Mechanopathology of Mycobacterium tuberculosis biofilm-like cords&#39; under review.&lt;/p&gt

    Multiplexed ionic current sensing with glass nanopores

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    We report a method for simultaneous ionic current measurements of single molecules across up to 16 solid state nanopore channels. Each device, costing less than $20, contains 16 glass nanopores made by laser assisted capillary pulling. We demonstrate simultaneous multichannel detection of double stranded DNA and trapping of DNA origami nanostructures to form hybrid nanopores
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