812 research outputs found
A dual-analytes responsive fluorescent probe for discriminative detection of ClO− and N2H4 in living cells
Hydrazine (N2H4) and ClO− are very harmful for public health, hence it is important and necessary to monitor
them in living cells. Herein, we rationally designed and synthesized a dual-analytes responsive fluorescent sensor
PTMQ for distinguishing detection of N2H4 and ClO−. PTMQ underwent N2H4-induced double bond cleavage,
affording colorimetric and green fluorescence enhancement with good selectivity and a low detection limit (89
nM). On the other hand, PTMQ underwent ClO−-induced sulfur oxidation and displayed red fluorescence
lighting-up response towards ClO− with good selectivity, rapid response (<0.2 min) and a low detection limit
(58 nM). Moreover, PTMQ was successfully employed for in-situ imaging of N2H4 and ClO− in living cellsinfo:eu-repo/semantics/publishedVersio
Optical effects of spin currents in semiconductors
A spin current has novel linear and second-order nonlinear optical effects
due to its symmetry properties. With the symmetry analysis and the eight-band
microscopic calculation we have systematically investigated the interaction
between a spin current and a polarized light beam (or the "photon spin
current") in direct-gap semiconductors. This interaction is rooted in the
intrinsic spin-orbit coupling in valence bands and does not rely on the Rashba
or Dresselhaus effect. The light-spin current interaction results in an optical
birefringence effect of the spin current. The symmetry analysis indicates that
in a semiconductor with inversion symmetry, the linear birefringence effect
vanishes and only the circular birefringence effect exists. The circular
birefringence effect is similar to the Faraday rotation in magneto-optics but
involves no net magnetization nor breaking the time-reversal symmetry.
Moreover, a spin current can induce the second-order nonlinear optical
processes due to the inversion-symmetry breaking. These findings form a basis
of measuring a pure spin current where and when it flows with the standard
optical spectroscopy, which may provide a toolbox to explore a wealth of
physics connecting the spintronics and photonics.Comment: 16 pages, 7 fig
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