Biorecognition and biocatalytic reactions of DNA monolayers, such as hybridization, polymerization, and hydrolytic digestion, were followed in situ by chronocoulometry and Faradaic impedance spectroscopy. Hydrophobic magnetic nanoparticles attracted to, and retracted from, the electrode surface by an external magnetic field were used to activate and inhibit the DNA-monolayer reactions, respectively. The attraction of the magnetic nanoparticles to the electrode surface generated a hydrophobic thin film on the surface that is not permeable for the water-soluble components required for the DNA-monolayer reactions. This results in the inhibition of the DNA-monolayer reactions. The retraction of the magnetic nanoparticles from the surface regenerated the free nucleic acid-functionalized surface that was exposed to the aqueous solution, thus reactivating the DNA-monolayer reactions. The reversible inhibition and activation of the DNA-monolayer reactions upon the cyclic attraction-retraction of the hydrophobic magnetic nanoparticles may be used to synthesize programmed DNA chips.
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http://dx.doi.org/10.1021/ja0517771 | DOI Listing |
Sci Rep
January 2025
College of Engineering, Applied Science University (ASU), Manama, Kingdom of Bahrain.
This paper presents an in-depth analytical investigation into the time-dependent flow of a Casson hybrid nanofluid over a radially stretching sheet. The study introduces the effects of magnetic fields and thermal radiation, along with velocity and thermal slip, to model real-world systems for enhancing heat transfer in critical industrial applications. The hybrid nanofluid consists of three nanoparticles-Copper and Graphene Oxide-suspended in Kerosene Oil, selected for their stable and superior thermal properties.
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January 2025
Department of Chemistry, Faculty of Science, Arak University, Arak, 38481-77584, Iran.
In this study, a novel hybrid nanostructure consisting of acid-decorated chitosan and magnetic AlFeO nanoparticles was fabricated. The acid-decorated chitosan provided a stable and biocompatible matrix for the magnetic AlFeO nanoparticles. Various techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction patterns (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), specific surface area (BET), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used to characterize and confirm the successful synthesis of the hybrid nanostructure.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
Biomedical Engineering , University of Wisconsin-Milwaukee College of Engineering and Applied Science, 3203 N Downer Ave, Milwaukee, Milwaukee, Wisconsin, 53211-3029, UNITED STATES.
Capacitive-based radiofrequency (Rf) radiation at 27 MHz offers a non-invasive approach for inducing hyperthermia, making it a promising technique for thermal cancer therapy applications. To achieve focused and site-specific hyperthermia, external material is required that efficiently convert Rf radiation into localized heat. Nanomaterials capable of absorbing Rf energy and convert into heat for targeted ablation are of critical importance.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Ural Federal University, Ekaterinburg, Russia.
This work is devoted to the study of the static magnetization of immobilized multi-core particles (MCPs) and their ensembles. These objects model aggregates of superparamagnetic nanoparticles that are taken up by biological cells and subsequently used, for example, as magnetoactive agents for cell imaging. In this study, we derive an analytical formula that allows us to predict the static magnetization of MCPs consisting of immobilized granules, in which the magnetic moment rotates freely the Néel mechanism.
View Article and Find Full Text PDFMater Today Bio
February 2025
Anhui University of Chinese Medicine, Hefei, 230012, China.
The therapeutic effect of immune checkpoint inhibitors (ICIs) in triple-negative breast cancer (TNBC) is unsatisfactory. The immune "cold" microenvironment caused by tumor-associated fibroblasts (TAFs) has an adverse effect on the antitumor response. Therefore, in this study, mixed cell membrane-coated porous magnetic nanoparticles (PMNPs) were constructed to deliver salvianolic acid B (SAB) to induce an antitumor immune response, facilitating the transition from a "cold" to a "hot" tumor and ultimately enhancing the therapeutic efficacy of immune checkpoint inhibitors.
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