We investigated the dynamics of polymer-grafted gold nanoparticles loaded into polymer melts using x-ray photon correlation spectroscopy. For low molecular weight host matrix polymer chains, normal isotropic diffusion of the gold nanoparticles is observed. For larger molecular weights, anomalous diffusion of the nanoparticles is observed that can be described by ballistic motion and generalized Lévy walks, similar to those often used to discuss the dynamics of jammed systems. Under certain annealing conditions, the diffusion is one-dimensional and related to the direction of heat flow during annealing and is associated with an dynamic alignment of the host polymer chains. Molecular dynamics simulations of a single gold nanoparticle diffusing in a partially aligned polymer network semiquantitatively reproduce the experimental results to a remarkable degree. The results help to showcase how nanoparticles can under certain circumstances move rapidly in polymer networks.
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http://dx.doi.org/10.1103/PhysRevLett.122.107802 | DOI Listing |
Nanoscale
January 2025
Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 557, India.
Chemotherapy is a crucial cancer treatment, but its effectiveness requires precise monitoring of drug concentrations in patients. This study introduces an innovative electrochemical strip sensor design to detect and continuously monitor methotrexate (MTX), a key chemotherapeutic drug. The sensor is crafted through an eco-friendly synthesis process that produces porous reduced graphene oxide (PrGO), which is then integrated with gold nanocomposites and polypyrrole (PPy) to boost the performance of a screen-printed carbon electrode (SPCE).
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemical Engineering, Ataturk University, 25240 Erzurum, Turkey.
The combination of plasmonic metals and MXene, as a new and interesting member of the 2D material class, may provide unique advantages in terms of low cost, versatility, flexibility, and improved activity as an ideal surface-enhanced Raman spectroscopy (SERS) platform. Despite the recent progress, the present studies on the utilization of plasmonic metal/MXene-based SERS systems are quite limited and thereby benefits of the extraordinary properties of this combination cannot be realized. In this study, for the first time, we propose layer-by-layer (LbL) thin films of TiC MXene and gold nanoparticles (AuNPs) as a robust SERS platform (TiC/AuNPs).
View Article and Find Full Text PDFSoft Matter
January 2025
Faculty of Chemistry, Ho Chi Minh City University of Science, Vietnam National University, Ho Chi Minh City, 227 Nguyen Van Cu Street, Ward 4, District 5, Ho Chi Minh City 70000, Vietnam.
Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive analytical technique with excellent molecular specificity. However, separate pristine nanoparticles produce relatively weak Raman signals. It is necessary to focus on increasing the "hot-spot" density generated at the nanogaps between the adjacent nanoparticles (second-generation SERS hotspot), thus significantly boosting the Raman signal by creating an electromagnetic field.
View Article and Find Full Text PDFCurr Drug Deliv
January 2025
School of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.
Introduction: Assessing the cytotoxicity of gold nanoparticles (GNPs) has gained importance due to their development in the biomedical field.
Method: In this study, we systematically synthesized gold nanorods (GNRs), gold nanobipyramids (GNBPs), and gold nanocups (GNCs) using a seed-mediated method, with an average length of 32.53 ± 4.
Mikrochim Acta
January 2025
School of Public Health, Jilin University, Changchun, Jilin, 130021, P. R. China.
A spherical nucleic acid (SNA, AuNPs-aptamer) into CRISPR/Cas12a system combined with poly T-template copper nanoparticles as fluorescence reporter was fabricated to establish an amplification-free sensitive method for Staphylococcus aureus (S. aureus) detection. This method, named PTCas12a, utilizes the concept that the bifunction of SNA recognizes the S.
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