Electric dipole polarizabilities and tune-out wavelengths for 23S1 and 33S1 states of Be2.

The electric dipole polarizabilities and the tune-out wavelengths for the n3S1 (n = 2, 3) states of Be2+ are determined through the application of the relativistic full-configuration-interaction approach. Our calculations directly integrate the mass shift operator into the Dirac-Coulomb-Breit Hamiltonian and further assess the quantum electrodynamics (QED) correction to the dynamic dipole polarizabilities using perturbation theory. The results reveal that the static electric dipole polarizability of the 23S1 and 33S1 states, as well as the 93 nm tune-out wavelength of the 23S1 state and the 238 nm tune-out wavelength of the 33S1 state, exhibits a high sensitivity to QED correction, which exceeds 80 ppm, providing a sensitive test for atomic structure theory.

Ratiometric fluorescence and smartphone dual-mode detection of glutathione using carbon dots coupled with Ag-triggered oxidation of o-phenylenediamine.

Developing ratiometric fluorescence and smartphone dual-mode bioanalysis methods is important but challenging. A ratiometric fluorescence method for determining glutathione (GSH) using carbon dots (CDs) and Ag-triggered o-phenylenediamine (OPD) oxidation is described here. Agoxidizes OPD to give 2,3-diaminophenazine (oxOPD), which effectively quenches CD fluorescence at 436 nm through the inner filter effect and causes a new emission peak at 561 nm.

Sensitive detection of picric acid in an aqueous solution using fluorescent nonconjugated polymer dots as fluorescent probes.

Nonconjugated polymer dots (NPDs) were successfully used as fluorescent probes to selectively and sensitively detect picric acid (PA). The NPDs were prepared from polyethylenimine and 1,4-phthalaldehyde under mild conditions and had excitation and emission maxima of 351 and 474 nm, respectively. Fluorescence of the NPDs was efficiently quenched by PA through the inner filter effect because of the overlapping PA absorption band and NPD excitation spectrum.

"Turn-on" fluorometric probe for α-glucosidase activity using red fluorescent carbon dots and 3,3',5,5'-tetramethylbenzidine.

A turn-on method for determining α-glucosidase activity is described using a chemical redox strategy in which the fluorescence of red fluorescent carbon dots (CDs) is modulated. The red fluorescent CDs were prepared using a solvothermal method with p-phenylenediamine and sodium citrate. The excitation and emission maxima of the CDs were 490 and 618 nm, respectively.

Preparation of nonconjugated fluorescent polymer nanoparticles for use as a fluorescent probe for detection of 2,4,6-trinitrophenol.

Water-soluble nonconjugated fluorescent polymer nanoparticles (NFPNs) were prepared from branched polyethylenimine (PEI) and citric acid through an amide condensation reaction in the aqueous phase. The NFPNs were characterized using a transmission electron microscope, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectra (XPS). The NFPN fluorescence (with excitation/emission peaks at 360/450 nm) was quenched by 2,4,6-trinitrophenol (TNP) at trace concentrations through the inner filter effect and the formation of self-assembled non-fluorescent Meisenheimer complexes of TNP on the NFPN surfaces through acid-base interactions.