Circular Polarization Conversion in Single Plasmonic Spherical Particles.

Temporal and spectral behaviors of plasmons determine their ability to enhance the characteristics of metamaterials tailored to a wide range of applications, including electric-field enhancement, hot-electron injection, sensing, as well as polarization and angular momentum manipulation. We report a dark-field (DF) polarimetry experiment on single particles with incident circularly polarized light in which gold nanoparticles scatter with opposite handedness at visible wavelengths. Remarkably, for silvered nanoporous silica microparticles, the handedness conversion occurs at longer visible wavelengths, only after adsorption of molecules on the silver.

Quantitative Polarization-Resolved Second-Harmonic-Generation Microscopy of Glycine Microneedles.

Second-harmonic generation (SHG) is a nonlinear optical process that can provide disease diagnosis through characterization of biological building blocks such as amino acids, peptides, and proteins. The second-order nonlinear susceptibility tensor χ of a material characterizes its tendency to cause SHG. Here, a method for finding the χ elements from polarization-resolved SHG microscopy in transmission mode is presented.

APTES Duality and Nanopore Seed Regulation in Homogeneous and Nanoscale-Controlled Reduction of Ag Shell on SiO Microparticle for Quantifiable Single Particle SERS.

Noble-metal nanoparticles size and packing density are critical for sensitive surface-enhanced Raman scattering (SERS) and controlled preparation of such films required to achieve reproducibility. Provided that they are made reliable, Ag shell on SiO microscopic particles (Ag/SiO) are promising candidates for lab-on-a-bead analytical measurements of low analyte concentration in liquid specimen. Here, we selected nanoporous silica microparticles as a substrate for reduction of AgNO with 3-aminopropyltriethoxysilane (APTES).