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The optical properties and surface-enhanced Raman scattering (SERS) of plasmonic nanodome array (PNA) substrates in air and aqueous solution are investigated. PNA substrates are inexpensively and uniformly fabricated with a hot spot density of 6.25 × 10(6) mm(-2) using a large-area nanoreplica moulding technique on a flexible plastic substrate. Both experimental measurement and numerical simulation results show that PNAs exhibit a radiative localized surface plasmon resonance (LSPR) due to dipolar coupling between neighboring nanodomes and a non-radiative surface plasmon resonance (SPR) resulting from the periodic array structure. The high spatial localization of electromagnetic field within the ∼10 nm nanogap together with the spectral alignment between the LSPR and excited and scattered light results in a reliable and reproducible spatially averaged SERS enhancement factor (EF) of 8.51 × 10(7) for Au-coated PNAs. The SERS enhancement is sufficient for a wide variety of biological and chemical sensing applications, including detection of common metabolites at physiologically relevant concentrations.
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http://dx.doi.org/10.1002/smll.201200712 | DOI Listing |
J Phys Chem B
September 2025
National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 11221, Taiwan, ROC.
The synthesis of -tetrakis(3,4,5-trimethoxyphenyl)porphyrin [HT(3,4,5-OCH)PP] and cobalt(II) -tetrakis(3,4,5-trimethoxyphenyl)porphyrin [Co(T(3,4,5-OCH)PP)] has been successfully accomplished. The oxidation properties of [Co(T(3,4,5-OCH)PP)] have been assessed through UV-vis, NMR, and EPR techniques. It can be seen in the UV-vis spectrum that adding SbCl caused extra peaks to appear at 674 nm, which means that a π-cation radical was formed.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
Università di Roma La Sapienza, Dipartimento di Fisica, Piazzale Aldo Moro 5, I-00185 Roma, Italy.
We develop an ab initio framework that captures the impact of electron-electron and electron-hole interactions on phonon properties. This enables the inclusion of excitonic effects in the optical phonon dispersions and lifetimes of graphene, both near the center (Γ) and at the border (K) of the Brillouin zone, at phonon-momenta relevant for Raman scattering and for the onset of the intrinsic electrical resistivity. Near K, we find a phonon redshift of ∼150 cm^{-1} and a 10× enhancement of the group velocity, together with a 5× increase in linewidths due to a 26× increase of the electron-phonon matrix elements.
View Article and Find Full Text PDFSmall
September 2025
Jožef Stefan Institute, Jamova cesta 39, Ljubljana, SI-1000, Slovenia.
The demand for rapid, field-deployable detection of hazardous substances has intensified the search for plasmonic sensors with both high sensitivity and fabrication simplicity. Conventional approaches to plasmonic substrates, however, often rely on lithographic precision or complex chemistries limiting scalability and reproducibility. Here, a facile, one-step synthesis of vertically aligned 2D nanosheets composed of intergrown CuO/CuO crystallites is presented, fabricated via oxygen plasma discharge on copper substrates.
View Article and Find Full Text PDFAnal Chem
September 2025
Department of Laboratory Medicine, Fujian Medical University, Fuzhou 350004, China.
Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in children. Current clinical diagnosis primarily relies on invasive detection methods, while molecular subtyping remains a complex and time-consuming process. This study innovatively employed silver nanoparticle-based surface-enhanced Raman spectroscopy (SERS) technology to systematically analyze 116 serum samples, including those with breakpoint cluster region-Abelson (-) fusion genotype, mixed-lineage leukemia (, also known as lysine methyltransferase 2A, ) gene rearrangement subtype, T-lymphoblastic ALL, and healthy controls.
View Article and Find Full Text PDFBeilstein J Nanotechnol
August 2025
Nanotechnology Lab, Research Laboratories of Saigon Hi-Tech Park, Lot I3, N2 Street, Tang Nhon Phu Ward, Ho Chi Minh City 70000, Vietnam.
Silver nanoprisms (AgNPrs) are promising candidates for surface-enhanced Raman scattering (SERS) due to their strong localized surface plasmon resonance and sharp tip geometry. In this study, AgNPrs were synthesized through a photochemical method by irradiating spherical silver nanoparticle seeds with 10 W green light-emitting diodes (LEDs; 520 ± 20 nm) for various periods of time up to 72 h. The growth mechanism was investigated through ultraviolet-visible spectroscopy, field-emission scanning electron microscopy, X-ray diffraction, and transmission electron microscopy analyses, confirming the gradual transformation of spherical seeds into AgNPrs.
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