Electron-Donating Benzenethiols Direct Rapid Formation of Plasmonic Gold Nanoflowers

The versatile world of MXene nanohybrids: designed synthesis, functional diversity, and promising theranostics

Arginine-engineered gold nanoclusters for doxorubicin chemiluminescence sensing

Gold-Decorated Oxidized Porous Silicon Nanoscaffolds as SERS Platform for Plasmonic Pesticide Sensing

The exploration of innovative materials for the chemical detection of organic contaminants remains an ongoing endeavor. Pesticides are a threat to human health because they are present in water bodies, crops, and processed foods. Oxidized porous silicon (OPSi) materials offer a versatile platform for plasmonic architectures by integrating a high surface area with adjustable optical properties. In this study, a Surface-Enhanced Raman Spectroscopy (SERS) substrate was developed by decorating OPSi layers with gold nanoislands through a controlled sputter deposition process. By systematically varying the gold deposition time, we identified clear correlations between the morphology of the nanoislands, localized surface plasmon resonance characteristics, and SERS improvement of the Raman signals. Scanning electron microscopy and UV–visible reflectance spectroscopy revealed a tunable plasmonic response, optimal at a 5 s deposition, where isolated islands maximize the electromagnetic hot-spot density without percolation. The optimized architecture facilitated sensitive, label-free detection of acetamiprid as a model pesticide analyte, achieving a detection limit of less than 0.2 μg/mL (8.9 8 × 10–7 mol/L) with a linear response from 0.2 to 15 μg/mL (8.98 × 10–7 to 6.37 × 10–5 mol/L). The substrate maintained spectral specificity in complex chemical environments, demonstrating that controlled gold deposition on OPSi layers produces a robust and reproducible SERS platform.

Optimization of gold nanorod dimer formation for enhanced plasmonic sensing applications

Anisotropic gold nanoparticles, such as gold nanorods, are of significant interest due to their tunable aspect ratios, which directly influence their optical properties and plasmonic behavior. Control over these parameters enables enhancement of plasmon resonance for applications in catalysis, photothermal therapeutics, and nano photonics. Self-assembled nanorod dimers further enhanced electric field for aforementioned applications. However, a major challenge in nanoparticle assembly is achieving a high yield of dimers while suppressing the formation of larger, uncontrolled aggregates. This research focuses on optimizing reaction conditions to promote selective dimer formation of gold nanorods through wet chemical methods with particular emphasis on pH control and reaction kinetics. By fine-tuning these parameters, the work aims to regulate interparticle coupling and minimize aggregation beyond the dimer state. Dimerized nanoparticles enable strong plasmonic coupling and localized electromagnetic field enhancement, which are critical for high sensitivity of plasmonic sensing applications. Structural and optical characterization of nanorod dimers are conducted using scanning electron microscopy, UV-Vis spectroscopy while dynamic light scattering is discussed as a complementary technique for evaluating size distribution and surface charge in solution. Overall, this work provides insight into the controlled formation of gold nanorod dimers and establishes strategies to enhance yield.

Seeded Growth of Plasmonic Core-Shell NU-1000 NanoMOFs With Intracellular Optical Readout.

Plasmonic gold bipyramids (AuBipy) encapsulated within a NU-1000 metal-organic framework (MOF) create robust core-shell nanocomposites. These porous nanoassemblies combine the near-infrared (NIR) plasmonic resonance of the metallic core with the intrinsic photoluminescence of the pyrene-based organic linkers. Comprehensive optical characterization reveals efficient photothermal heating under NIR irradiation and robust surface-enhanced Raman scattering (SERS) capabilities in colloidal dispersions. For biological applications, AuBipy@NU-1000 nanocomposites exhibit good colloidal stability and maintain high cell viability in A549 cells up to a 200 pM particle concentration (equivalent to 152 µM of Au and 302 µM of Zr). Wide-field hyperspectral microscopy enables label-free intracellular mapping of the distinct optical signatures of both components after cellular internalization. Spatial analysis of these signals supports preservation of the core-shell architecture inside cells. Consequently, these nanomaterials provide a versatile platform for intracellular optical readout, with additional potential for chemical sensing and photothermal applications.

Interface Self-Assembly of Au10 Nanoclusters for Enhanced Electrochemiluminescence and Alzheimer's Disease Biomarker Detection.

This study reported the interface self-assembly of Au10 nanoclusters for the first time, and ultimately formed a fibrous structure with a high aspect ratio, Au10-Fiber, which is an innovative approach that significantly enhances the ECL activity of Au10 NCs.