Yuejiao Gu

Hierarchical Structural Nanopore Arrays Fabricated by Pre‐patterning Aluminum using Nanosphere Lithography

A highly ordered and hierarchical structural nanopore array is fabricated via anodizing a pre-patterned aluminum foil under an optimized voltage. A pre-patterned hexagonal nanoindentation array on an aluminum substrate is prepared via the nanosphere lithography method. This pattern leads to an elaborate nanochannel structure with seven nanopores in each nanoindentation after anodization treatment. The structure achieved in our study is new, interesting, and likely to be applied in photonic devices.

Propagating and localized surface plasmons in hierarchical metallic structures for surface-enhanced Raman scattering.

PSPs spread along the metal fi lm, which are most commonly employed using prisms to couple light into the metal in Kretschmann/Otto confi gurations, [ 6 , 7 ] also can be coupled using periodic gratings or waveguide confi gurations. [ 4 , 8 ] The characteristics of PSPs are that they can effectively transform the energy of incident light into surface wave, and the excitation and emission are dependent on the incident angle. However, the electromagnetic enhancement from the multiples of PSPs is trivial. [ 9 ] In contrast, LSPs, excited from rough metal surfaces and localized on metal nanostructures, can enhance the electromagnetic fi eld around the metal nanostructures. [ 10 ]

Note: Raman microspectroscopy integrated with fluorescence and dark field imaging

A Raman detection platform integrated with both fluorescence and dark field microscopes was built for in situ Raman detection with the assistance of fluorescence and dark field imaging to locate the target micro regions. Cells and organelles can be easily found via fluorescence imaging with labeling techniques. Besides, nano-sized particles could be observed and located by dark field microscopes. Therefore, comparing with the commercial Raman spectrometers, much more researches based on Raman spectroscopy could be carried out on this integrated Raman platform, especially in the fields of analyzing biological tissues and subwavelength samples.

Active modulation of wavelength and radiation direction of fluorescence via liquid crystal-tuned surface plasmons

Plasmonic elements which can tune light in micro-nano dimension have attracted much attention nowadays. However, available approaches for externally manipulating surface plasmons (SPs) are still in great demand. Here, we described an effective approach to modulate SPs by voltage signal. Through adding a liquid crystal cell with a dye layer to the Kretschmann configuration, the wavelength and the radiation direction of the fluorescence of dye can be modulated continuously and reversibly by changing applied voltages. This design has great application potentials in the development of tunable luminescent devices and smart plasmonic elements.

Note: Mobile micro-Raman analyzer integrated with a lab-on-a-chip

A mobile micro-Raman microfluidic analyzer was designed and built for label-free, nondestructive, fingerprint detection of samples on microfluidic chip systems. It mainly includes an optical module (including the Raman detection system and the microscopic imaging system), 3-axis stages with step motors and other auxiliary circuits. The setup of the analyzer was designed with fully considering the characters of the microfluidics system. The experimental results prove that this microfluidics analyzer is practical and very convenient to use. This micro-Raman microfluidics analyzer with high performance to cost ratio has wide application potential in lab-on-a-chip fields as a powerful analytical tool.