Dielectric spectroscopy measurements were performed for aqueous solutions of short single-stranded DNA with 30 to 120 bases of thymine over a frequency range of 10;{5} to 10;{8}Hz . Dielectric dispersion was found to include two relaxation processes in the ranges from 10;{5} to 10;{6} and from 10;{6} to 10;{8}Hz , respectively, with the latter mainly discussed in this study. The dielectric increment and the relaxation time of the high-frequency relaxation of DNA in solutions without added salt exhibited concentration and polymer-length dependences eventually identical to those for dilute polyion solutions described in previous studies. For solutions with added salt, on the other hand, those dielectric parameters were independent of salt concentration up to a certain critical value and started to decrease with further increasing salt concentration. This critical behavior is well explained by our newly extended cell model that takes into account the spatial distribution of loosely bound counterions around DNA molecules as a function of salt concentration.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevE.75.011911 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Division of Micro and Nanosystems (MST), School of Electrical Engineering and Computer Science (EECS), KTH Royal Institute of Technology, Stockholm SE-10044, Sweden.
Controlled breakdown has emerged as an effective method for fabricating solid-state nanopores in thin suspended dielectric membranes for various biomolecular sensing applications. On an unpatterned membrane, the site of nanopore formation by controlled breakdown is random. Nanopore formation on a specific site on the membrane has previously been realized using local thinning of the membrane by lithographic processes or laser-assisted photothermal etching under immersion in an aqueous salt solution.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
Bubbles present in saline water typically exhibit a prolonged lifetime, making them attractive for various engineering processes. Herein, we unveil a transition from delayed bubble coalescence to rapid bursting within about one millisecond in salty solutions. The key aspect in understanding this transition lies in the combined influences of surface deformation and ion surface excess instead of characterizing the ions alone.
View Article and Find Full Text PDFNanoscale
January 2025
College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China.
High salinity in wastewater often hampers the performance of traditional adsorbents by disrupting electrostatic interactions and ion exchange processes, limiting their efficiency. This study addresses these challenges by investigating the salt-promoted adsorption of Cu ions onto amino-functionalized chloromethylated polystyrene (EDA@CMPS) millispheres. The adsorbent was synthesized by grafting ethylenediamine (EDA) onto CMPS, which significantly improved Cu adsorption, achieving nearly three times the capacity in saline solutions (1.
View Article and Find Full Text PDFNanoscale
January 2025
College of Chemical Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Interfacial solar vapor generation (ISVG) accompanied by photocatalytic degradation holds immense potential to mitigate water scarcity and pollution. Distinct from the two detached functional components (photothermal agent and photocatalyst) in a conventional evaporator, in this study, an all-in-one photothermal/catalytic agent, nitrogen-containing honeycomb carbon nanosheets (NHC), was engineered for synergistic high-efficiency steam generation and photocatalysis functions. It was demonstrated that the superoxide radical generated on the surface of NHC conferred its catalytic activity to the photodegradation of organic pollutants under full solar spectrum irradiation.
View Article and Find Full Text PDFAnal Methods
January 2025
CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), G. B. Marg, Bhavnagar, 364 002, India.
In this study, magnesium-doped lithium manganese oxide nanoparticles were prepared through a solid-state reaction technique, and their surface was modified with mesoporous silica. The surface-modified material exhibited a significantly enhanced BET surface area from 5.791 to 66.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!