A new optical scattering contrast-agent based on polymer-nanoparticle encapsulated silver nanoplates (PESNs) is presented. Silver nanoplates were chosen due to the flexibility of tuning their plasmon frequencies. The polymer coating preserves their physical and optical properties and confers other advantages such as controlled contrast agent delivery. Finite difference time domain (FDTD) simulations model the interaction of light with the nanoplates in different orientations in the cluster. Hyperspectral dark field microscopy (HYDFM) observes the scattering spectra of the PESNs. An unsupervised sequential maximum angle convex cone (SMACC) image analysis resolves spectral endmembers corresponding to different stacking orientations of the nanoplates. The orientation-dependent endmembers qualitatively agree with the FDTD results. For contrast enhancement, the uptake and spatial distribution of PESNs are demonstrated by an HYDFM study of single melanoma cells to result in an enhanced contrast of up to 400%. A supervised spatial mapping of the endmembers obtained by the unsupervised SMACC algorithm reveals spatial distributions of PESNs with various clustering orientations of encapsulated nanoplates. Our study demonstrates tunability in plasmonics properties in clustered metal nanoparticles and its utility for the development of scatter-based imaging contrast agents for a broad range of applications, including studies of single cells and other biomedical systems.
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http://dx.doi.org/10.1002/jbio.201500177 | DOI Listing |
Chemphyschem
December 2024
Department of Physical Chemistry and Microreaction Technology, Institute for Chemistry and Biotechnology, TU Ilmenau, Weimarer Straße 32, 98693, Ilmenau, Germany.
We are presenting an easy synthetic access to the aqueous synthesis of truncated trigonal silver nanobipyramids with tunable width and height in a facile two step synthesis. We modified a synthesis that employs seed particles with twinning faults on which silver is deposited laterally along the twinning fault, leading to flat particles. The ratio of lateral and vertical growth is adjusted by the co-titration of further noble metal salts at nanomolar concentrations alongside the silver precursor.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
BIOSCOPE Research Group, LAQV-REQUIMTE, Chemistry Department, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; PROTEOMASS Scientific Society, Costa de Caparica, 2825-466, Portugal. Electronic address:
Nanoscale Adv
October 2024
Department of Clinical Chemistry, Faculty of Medical Technology, Mahidol University, 999 Phutthamonthon 4 Road, Salaya Nakhon Pathom 73170 Thailand
A novel colorimetric method utilizing a bi-enzyme assay using silver nanoplates (AgNPls) as a direct signal source was developed to enable rapid insecticide detection. This innovative system leverages the generated HO from the consecutive enzyme-catalyzed reactions of acetylcholine hydrolysis and choline oxidation to introduce oxidative etching of AgNPls, transforming them into aggregated silver nanospheres (AgNSs). The morphological transformation of silver nanoparticles could be observed with the naked eye due to the solution's color shifts from pink-violet to blue-violet.
View Article and Find Full Text PDFFood Chem
February 2025
State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, PR China. Electronic address:
Multiple and sensitive mycotoxin detection is an essential early-warning mechanism for safeguarding human health, and preserving the environment. We synthesized a turn-on Fluorescence Resonance Energy Transfer (FRET) aptamer sensor based on the unique fluorescence quenching and substrate recognition characteristics of Ag NTs (energy receptors) and aptamer modified FeO@TiO NP (energy donor) to detect multiple toxins using a single diagnostic approach. The addition of aflatoxin B1 (AFB1) and ochratoxin A (OTA) resulted in a change in fluorescence intensity at 510 and 650 nm, which can be employed for simultaneous recognition with detection limits of 0.
View Article and Find Full Text PDFNanotechnology
September 2024
Institute of Physics, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan.
Reliable and cost-effective glucose sensors are in rising demand among diabetes patients. The combination of metals and conducting polymers creates a robust electrocatalyst for glucose oxidation, offering enzyme-free, high stability, and sensitivity with outstanding electrochemical results. Herein, graphene is grown on nickel foam by chemical vapor deposition to make a graphene@nickel foam scaffold (G@NF), on which silver nanoplates-polyaniline (Ag-PANI) 3D architecture is developed by sonication-assisted co-electrodeposition.
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