We report on Raman spectroscopy of few quintuple layer topological insulator bismuth selenide (Bi2Se3) nanoplatelets (NPs), synthesized by a polyol method. The as-grown NPs exhibit excellent crystalline quality, hexagonal or truncated trigonal morphology, and uniformly flat surfaces down to a few quintuple layers. Both Stokes and anti-Stokes Raman spectroscopy for the first time resolve all fou...

Tuning the emission energy of graphene quantum dots (GQDs) and understanding the reason of tunability is essential for the GOD function in optoelectronic devices. Besides material-based challenges, the way to realize chemical doping and band gap tuning also pose a serious challenge. In this study, we tuned the emission energy of GQDs by substitutional doping using chlorine, nitrogen, boron, sod...

We present the concept of combining circularly polarized luminescence (CPL) and excited-state intramolecular proton transfer (ESIPT) features into a single molecule as strategy to generate high-performance ESIPT-based CPL materials. For this purpose, [6]helicene bearing two ESIPT structural units was synthesized using double Suzuki–Miyaura reaction C(sp2)−H hydroxylation approach. The photophys...

The emission maximum of DPN-linked isocitrate dehydrogenase in pH 7.07 buffer is shifted from 317 to 324 nm and fluorescence intensity is decreased when the excitation wave-length is varied from 270 to 290 nm; in 0.2 M KOH, where the fluorescence of tyrosyl residues is almost completely quenched, a further substantial decline in quantum yield of protein fluorescence and a red shift of the emiss...

In order to confirm the prediction of the General Theory of Relativity that space and time are relative and that matter warps a dynamic space-time continuum that surrounds it, Einstein suggested two optical tests: one being the gravitational deflection of starlight, and the second being the gravitational red shift. The tests confirmed the predictions of the General Theory of Relativity. The obs...

The carbon, nitrogen, and oxygen K-edge spectra were measured for aqueous solutions of glycine by total electron yield near-edge X-ray absorption fine structure (TEY NEXAFS) spectroscopy. The bulk solution pH was systematically varied while maintaining a constant amino acid concentration. Spectra were assigned through comparisons with both previous studies and ab initio computed spectra of isol...

A systematic investigation into the relationship between the solid-state luminescence and the intermolecular Au⋅⋅⋅Au interactions in a series of pyrazolate-based gold(I) trimers; tris(μ2 -pyrazolato-N,N')-tri-gold(I) (1), tris(μ2 -3,4,5- trimethylpyrazolato-N,N')-tri-gold(I) (2), tris(μ2 -3-methyl-5-phenylpyrazolato-N,N')-tri-gold(I) (3) and tris(μ2 -3,5-diphenylpyrazolato-N,N')-tri-gold(I) (4)...

The linear Doppler shift is familiar as the rise and fall in pitch of a siren as it passes by. Less well known is the rotational Doppler shift, proportional to the rotation rate between source and receiver, multiplied by the angular momentum carried by the beam. In extreme cases the Doppler shift can be larger than the rest-frame frequency and for a red shift, the observed frequency then become...

A new detection mechanism has been developed for low molecular weight substrate binding to heme proteins based on resonance localized surface plasmon spectroscopy. Cytochrome P450 has strong electronic transitions in the visible wavelength region. Upon binding of a substrate molecule (e.g., camphor), the absorption band of cytochrome P450 shifts to shorter wavelength. The event of camphor bindi...

To gain information about the properties of tyrosyl residues buried within proteins, the circular dichroism (CD) and absorption spectra of tyrosine derivatives have been investigated in nonpolar solvents. N-Stearyl-L-tyrosine n-hexyl ester dissolved in methylcyclohexane (O-O band at 283 nm) was used to measure the effects of hydrogen-bonding agents. Adding low concentrations of dioxane, N, N-di...