Next-Generation Wearable Biosensors Developed with Flexible Bio-Chips.

The development of biosensors that measure various biosignals from our body is an indispensable research field for health monitoring. In recent years, as the demand to monitor the health conditions of individuals in real time have increased, wearable-type biosensors have received more attention as an alternative to laboratory equipment. These biosensors have been embedded into smart watches, clothes, and accessories to collect various biosignals in real time.

Davydov Splitting and Excitonic Resonance Effects in Raman Spectra of Few-Layer MoSe2.

Raman spectra of few-layer MoSe2 were measured with eight excitation energies. New peaks that appear only near resonance with various exciton states are analyzed, and the modes are assigned. The resonance profiles of the Raman peaks reflect the joint density of states for optical transitions, but the symmetry of the exciton wave functions leads to selective enhancement of the A1g mode at the A exciton energy and the shear mode at the C exciton energy.

Raman Spectroscopic Study on Alkyl Chain Conformation in 1-Butyl-3-methylimidazolium Ionic Liquids and their Aqueous Mixtures.

Ionic liquids of 1-butyl-3-methylimidazolium ([BMIM]) cation with different anions (Cl , Br , I , and BF ), and their aqueous mixtures were investigated by using Raman spectroscopy and dispersion-included density functional theory (DFT). The characteristic Raman bands at 600 and 624 cm for two isomers of the butyl chain in the imidazolium cation showed significant changes in intensity for different anions as well as in aqueous solutions. The area ratio of these two bands followed the order I >Br >Cl >BF (in terms of the anion X in [BMIM]X), indicating that the butyl chain of [BMIM]I tends to adopt the trans conformation.

Excitation energy dependent Raman spectrum of MoSe2.

Raman investigation of MoSe2 was carried out with eight different excitation energies. Seven peaks, including E1g, A1g, E2g(1), and A2u(2) peaks are observed in the range of 100-400 cm(-1). The phonon modes are assigned by comparing the peak positions with theoretical calculations.

Polarization-independent light emission enhancement of ZnO/Ag nanograting via surface plasmon polariton excitation and cavity resonance.

In this study, we observed that the photoluminescence (PL) intensity of ZnO/Ag nanogratings was significantly enhanced compared with that of a planar counterpart under illumination of both transverse magnetic (TM) and transverse electric (TE)-mode light. In the TM mode, angle-resolved reflectance spectra exhibited dispersive dips, indicating cavity resonance as well as grating-coupled surface plasmon polariton (SPP) excitation. In the TE mode, cavity resonance only was allowed, and broad dips appeared in the reflectance spectra.