Core-shell or striped heteroatomic lanthanide metal-organic framework hierarchical single crystals were obtained by liquid-phase anisotropic epitaxial growth, maintaining identical periodic organization while simultaneously exhibiting spatially segregated structure. Different types of domain and orientation-controlled multicolor photophysical models are presented, which show either visually distinguishable or visible/near infrared (NIR) emissive colors. This provides a new bottom-up strategy toward the design of hierarchical molecular systems, offering high-throughput and multiplexed luminescence color tunability and readability. The unique capability of combining spectroscopic coding with 3D (three-dimensional) microscale spatial coding is established, providing potential applications in anti-counterfeiting, color barcoding, and other types of integrated and miniaturized optoelectronic materials and devices.
On-chip plasmon-induced transparency offers the possibility of realization of ultrahigh-speed information processing chips. Unfortunately, little experimental progress has been made to date because it is difficult to obtain on-chip plasmon-induced transparency using only a single meta-molecule in plasmonic circuits. Here, we report a simple and efficient strategy to realize on-chip plasmon-induced transparency in a nanoscale U-shaped plasmonic waveguide side-coupled nanocavity pair. High tunability in the transparency window is achieved by covering the pair with different organic polymer layers. It is possible to realize ultrafast all-optical tunability based on pump light-induced refractive index change of a graphene cover layer. Compared with previous reports, the overall feature size of the plasmonic nanostructure is reduced by more than three orders of magnitude, while ultrahigh tunability of the transparency window is maintained. This work also provides a superior platform for the study of the various physical effects and phenomena of nonlinear optics and quantum optics.
Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm2 order. Here, we report an ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials coated on polycrystalline indium-tin oxide layer at the optical communication range. Compared with previous reports, the threshold pump intensity is reduced by four orders of magnitude, while an ultrafast response time of picoseconds order is maintained. This work not only offers a way to constructing photonic materials with large nonlinearity and ultrafast response, but also opens up the possibility for realizing quantum solid chips and ultrafast integrated photonic devices based on metamaterials.
Rheumatoid arthritis (RA) is a common chronic autoimmune inflammatory disease, and its etiology is closely related to the overproduction of hypochlorous acid (HClO). However, early detection of RA using an activatable near-infrared-II (NIR-II, 1000−1700 nm) fluorescent probe remains challenging. Herein, we first report an "OFF− ON" NIR-II fluorescent probe named PTA (phenothiazine triphenylamine) for imaging HClO in deep-seated early RA. Electron-rich phenothiazine in the core of PTA was utilized as both an HClOrecognition moiety and a precursor of electron acceptors, displaying a typical donor−acceptor−donor structure with excellent NIR-II emission at 936/1237 nm once reacted with HClO. The probe PTA exhibited good water solubility, high photostability, and rapid response capability toward HClO within 30 s. Moreover, it was able to sensitively and specifically detect exogenous and endogenous HClO in living cells in both visible and NIR-II windows. Notably, PTA enabled the sensitive and rapid visualization of HClO generation in an inflammatory RA mouse model, showing a 4.3-fold higher NIR-II fluorescence intensity than that in normal hindlimb joints. These results demonstrate that PTA holds great promise as a robust platform for diagnosis of HOCl-mediated inflammatory disorders.
Near-infrared
(NIR) and mid-infrared (MIR) photodetectors have
wide applications in biometrics, military, industry, etc. NIR and
MIR organic photodetectors (OPD) require narrow-bandgap semiconductors
to achieve efficient light absorption. However, it is still a challenge
to synthesize organic materials with efficient absorption region above
1000 nm. Herein, a flexible hybrid OPD has been designed and fabricated
by integrating organic materials with three-dimensional graphene (3DG)
film, and the photodetector can detect light from visible to MIR at
room temperature with an outstanding responsivity of 108 A W–1 in the NIR region (1000 nm). Moreover, the hybrid device can detect
picowatt-level light with ultrahigh responsivity of 5.8 × 105 A W–1 and specific detectivity of 3 ×
1015 Jones in the visible region. Furthermore, the 3DG
film/organic hybrid detector is well compatible with flexible substrates
and opens up a novel approach to developing flexible photodetectors
with high responsivity in a wide spectrum range, suggesting possible
potential applications in flexible electronics.
A novel dynamic covalent gel has been prepared via the imine bond formation reaction of tetraamine building blocks with luminescent tetraphenylethene tetraaldehyde units. The gel shows high hierarchical porosity (SBET = 512 m(2) g(-1)) and remarkable aggregation-induced emission enhancement, which has been demonstrated to be a selective sensor.
Two zwitterionic-type ligands featuring π-π* and intraligand charge-transfer (ILCT) excited states, namely 1,1'-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)dipyridinium-4-olate (TMPBPO) and 1-dodecylpyridin-4(1 H)-one (DOPO), have been prepared and applied to the assembly of lanthanide coordination complexes in an effort to understand the ligand-direction effect on the structure of the Ln complexes and the ligand sensitization effect on the luminescence of the Ln complexes. Due to the wide-band triplet states plus additional ILCT excitation states extending into lower energy levels, broadly and strongly sensitized photoluminescence of f→f transitions from various Ln(3+) ions were observed to cover the visible to near-infrared (NIR) regions. Among which, the Pr, Sm, Dy, and Tm complexes simultaneously display both strong visible and NIR emissions. Based on the isostructural feature of the Ln complexes, color tuning and single-component white light was achieved by preparation of solid solutions of the ternary systems Gd-Eu-Tb (for TMPBPO) and La-Eu-Tb and La-Dy-Sm (for DOPO). Moreover, the visible and NIR luminescence lifetimes of the Ln complexes with the TMPBPO ligand were investigated from 77 to 298 K, revealing a strong temperature dependence of the Tm(3+) ((3) H4 ) and Yb(3+) ((2) F5/2 ) decay dynamics, which has not been explored before for their coordination complexes.
Inflammatory
bowel disease (IBD) is a common gastrointestinal inflammatory
disease, affecting a huge number of people worldwide with increasing
morbidity each year. Although the etiology of IBD has not been fully
elucidated, it is understood to be closely related to upregulation
of the production of NO. Herein, we first report a donor–acceptor–donor
(D–A–D)-type near-infrared (NIR) fluorescent probe LS-NO for real-time detection of NO in IBD by harnessing the
enhanced intramolecular charge transfer mechanism. LS-NO exhibited good water solubility, high photostability, and excellent
NIR absorbance and emission at 700 and 750/800 nm, respectively. Moreover,
it was able to sensitively and specifically detect exogenous and endogenous
NO in the lysosomes of living cells. Notably, LS-NO enabled
to noninvasively visualize NO generation in a lipopolysaccharide-induced
IBD mouse model for 30 h, showing a two- to threefold higher NIR fluorescence
intensity in the intestines and feces of IBD mice than normal mice.
This work demonstrates that LS-NO is promising as a diagnosis
agent for real-time detection of NO in IBD and may promote inflammatory
stool examination simultaneously.
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