This paper describes the use of gold nanoparticles to study particle translocation dynamics through silicon nitride solid-state nanopores. Gold nanoparticles were dispersed in 20 mM KCl solution containing nonionic surfactant Triton X-100 and their translocation was studied at different applied voltages. The use of low electrolyte concentration resulted in current enhancement upon particle translocation. The counterion cloud around the nanoparticles is proposed to be the reason for current enhancement phenomena because associated counterion cloud is believed to increase the ion density inside the pore during particle translocation. Further, single particle diffusion events were also recorded at 0 mV voltage bias and 0 pA background ionic current with high signal-to-noise ratio as the particles moved down their concentration gradient. The ability of nanopore sensors to detect single particle diffusion can be extended to field-free analysis of biomolecules in their native state and at or near physiological salt concentrations.
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http://dx.doi.org/10.1021/ac4012045 | DOI Listing |
Soft Matter
January 2025
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA.
The capillary break-up of complex fluid filaments occurs in many scientific and industrial applications, particularly in bio-printing where both liquid and polymerized droplets exist in the fluid. The simultaneous presence of fluid and solid particles within a carrier fluid and their interactions lead to deviations in the filament break-up from the well-established capillary breakup dynamics of single-phase liquids. To examine the significance of the dispersed phase and the internal interactions between liquid droplets and solid particles, we prepare emulsions through photopolymerization and conduct experimental investigations into the pinch-off dynamics of fluid filaments, focusing on the impact of varying concentrations of liquid droplets (before polymerization) and polymerized droplets.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Chemistry, Michigan State University, East Lansing, MI 48824.
The natural vibrational frequencies of biological particles such as viruses and bacteria encode critical information about their mechanical and biological states as they interact with their local environment and undergo structural evolution. However, detecting and tracking these vibrations within a biological context at the single particle level has remained elusive. In this study, we track the vibrational motions of single, unlabeled virus particles under ambient conditions using ultrafast spectroscopy.
View Article and Find Full Text PDFNano Lett
January 2025
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
The transformation of bulk transition-metal dichalcogenide (TMD) particles into ultrathin nanosheets with both an acceptable yield and preserved crystalline integrity presents a substantial challenge in electrochemical exfoliation. This challenge arises from the continuous potential stress that the materials experience in traditional exfoliation setups. Herein, we propose a new fluidized electrochemical exfoliation (FEE) method to efficiently transform TMD powders into high-quality, few-layered TMD nanosheets in the aqueous phase.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin cancer with limited treatment options, often associated with Merkel cell polyomavirus (MCPyV) and marked by hypoxic tumor microenvironments that promote resistance to therapies. Belzutifan, an FDA-approved hypoxia-inducible factor-2α (HIF-2α) inhibitor, has shown promise in inhibiting tumor growth; however, its clinical efficacy is hindered by its low solubility, rapid clearance, and limited bioavailability. In this study, we present a strategy using porous silicon (pSi) microparticles and nanoparticles as carriers for the sustained delivery of benzoate to MCC cells.
View Article and Find Full Text PDFNat Commun
January 2025
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, PR China.
Defect engineering can create various vacancy configurations in catalysts by finely tuning the local electronic and geometric structures of the active sites. However, achieving precise control and identification of these defects remains a significant challenge, and the origin of vacancy configurations in catalysts, especially clustered or associated ones, remains largely unknown. Herein, we successfully achieve the controllable fabrication and quantitative identification of triple O-Ti-O vacancy associate (VVV) in nanosized Ni-doped TiO.
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