Surface Enhanced FluorescenceWhen a noble metal with nanostructure is irradiated with light, localized surface plasmons are resonantly generated, i.e., "plasmon resonance" occurs, which enhances various physical and chemical processes near the surface, e.g., Raman scattering or fluorescence intensities of molecules, [1][2][3][4] photoconversion efficiency of solar cell, [5,6] and yield of photochemical reactions. [7,8] Enhanced fluorescence intensity is termed surface-enhanced

Titanium dioxide (TiO 2 ) is a crucial semiconductor for photocatalysts, solar cells, hydrogen evolution reactions, and antivirus agents. The properties and performances of these applications can improve significantly if the integrated TiO 2 acts as a light harvester through a large field enhancement. This study investigates the electromagnetic field enhancement of a nanogap-rich TiO 2 film with a large area, prepared by a facile dry process at room temperature. Herein, the loading pressure is applied to the TiO 2 particles for closely packing them in the film. The field enhancement, as a function of the loading pressure, is explored from the fluorescence intensity enhancement of a dye molecule. An average enhancement factor >2000 is achieved, which is a remarkable record for semiconductors. Furthermore, the reproducibility is significant; the relative standard deviation value is small (∼4%). Calculations were performed using the finite-difference-time-domain method. A nanogap of 5 nm yields the highest EF for triangular-prism TiO 2 particles.

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The Prelog-Djerassi lactone, a key intermediate for the synthesis of several medicinally important macrolide antibiotics, and protomycinolide IV, a 16-membered macrolide, have been synthesized by employing the recently developed stereospecific methylation of γ,δ-epoxy acrylates by trimethylaluminum as key steps.