Highly Efficient Organic Solar Cells with Improved Vertical Donor-Acceptor Compositional Gradient Via an Inverted Off-Center Spinning Method.

A novel, yet simple solution fabrication technique to address the trade-off between photocurrent and fill factor in thick bulk heterojunction organic solar cells is described. The inverted off-center spinning technique promotes a vertical gradient of the donor-acceptor phase-separated morphology, enabling devices with near 100% internal quantum efficiency and a high power conversion efficiency of 10.95%.

A pH-activatable and aniline-substituted photosensitizer for near-infrared cancer theranostics.

This work reports a newly designed pH-activatable and aniline-substituted aza-boron-dipyrromethene as a trifunctional photosensitizer to achieve highly selective tumor imaging, efficient photodynamic therapy (PDT) and therapeutic self-monitoring through encapsulation in a cRGD-functionalized nanomicelle. The diethylaminophenyl is introduced in to the structure for pH-activatable near-infrared fluorescence and singlet oxygen (O) generation, and bromophenyl is imported to increase the O generation efficiency upon pH activation by virtue of its heavy atom effect. After encapsulation, the nanoprobe can target αβ integrin-rich tumor cells cRGD and is activated by physiologically acidic pH for cancer discrimination and PDT.

Aptamer loaded MoS2 nanoplates as nanoprobes for detection of intracellular ATP and controllable photodynamic therapy.

In this work we designed a MoS2 nanoplate-based nanoprobe for fluorescence imaging of intracellular ATP and photodynamic therapy (PDT) via ATP-mediated controllable release of (1)O2. The nanoprobe was prepared by simply assembling a chlorine e6 (Ce6) labelled ATP aptamer on MoS2 nanoplates, which have favorable biocompatibility, unusual surface-area-to-mass ratio, strong affinity to single-stranded DNA, and can quench the fluorescence of Ce6. After the nanoprobe was internalized into the cells and entered ATP-abundant lysosomes, its recognition to ATP led to the release of the single-stranded aptamer from MoS2 nanoplates and thus recovered the fluorescence of Ce6 at an excitation wavelength of 633 nm, which produced a highly sensitive and selective method for imaging of intracellular ATP.

Ultra-bright near-infrared-emitting HgS/ZnS core/shell nanocrystals for in vitro and in vivo imaging.

Near-infrared (NIR)-emitting nanocrystals have enormous potential as an enabling technology for applications ranging from tunable infrared lasers to biological labels. Mercury chalcogenide NCs are one of the attractive NCs with NIR emission; however, the potential toxicity of Hg restricts their diverse applications. Herein, we synthesized low-toxic, highly luminescent and stable GSH-capped HgS/ZnS core/shell NCs by an aqueous route for the first time.

How do nitrogen-doped carbon dots generate from molecular precursors? An investigation of the formation mechanism and a solution-based large-scale synthesis.

A bottom-up method, using monoethanolamine (MEA) as both a passivation agent and a solvent, has been developed for rapid and massive synthesis of nitrogen-doped carbon dots (N-C-dots) from citric acid under heating conditions. This method requires a relatively mild temperature (170 °C) without special equipment, and affords one-pot large-scale production (39.96 g) of high-quality N-C-dots (quantum yield of 40.

Highly fluorescent, near-infrared-emitting Cd²⁺-tuned HgS nanocrystals with optical applications.

Bulk HgS itself has proven to be a technologically important material; however, the poor stability and weak emission of HgS nanocrystals have greatly hindered their promising applications. Presently, a critical problem is the uncontrollable growth of HgS NCs and their intrinsic surface states which are susceptible to the local environment. Here, we address the issue by an ion-tuning approach to fabricating stable, highly fluorescent Cd:HgS/CdS NCs for the first time, which efficiently tuned the band-gap level of HgS NCs, pushing their intrinsic states far away from the surface, reducing the strong interaction of the environment with surface states and hence drastically boosting the exciton transition.

Folate receptor-targeted and cathepsin B-activatable nanoprobe for in situ therapeutic monitoring of photosensitive cell death.

The integration of diagnostic and therapeutic functions in a single system holds great promise to enhance the theranostic efficacy and prevent the under- or overtreatment. Herein, a folate receptor-targeted and cathepsin B-activatable nanoprobe is designed for background-free cancer imaging and selective therapy. The nanoprobe is prepared by noncovalently assembling phospholipid-poly(ethylene oxide) modified folate and photosensitizer-labeled peptide on the surface of graphene oxide.

A multifunctional nanomicelle for real-time targeted imaging and precise near-infrared cancer therapy.

Simultaneous targeted cancer imaging, therapy and real-time therapeutic monitoring can prevent over- or undertreatment. This work describes the design of a multifunctional nanomicelle for recognition and precise near-infrared (NIR) cancer therapy. The nanomicelle encapsulates a new pH-activatable fluorescent probe and a robust NIR photosensitizer, R16FP, and is functionalized with a newly screened cancer-specific aptamer for targeting viable cancer cells.

Integrated molecular, interfacial, and device engineering towards high-performance non-fullerene based organic solar cells.

High-performance non-fullerene OSCs with PCEs of up to ca. 6.0% are demonstrated based on PBDTT-F-TT polymer and a molecular di-PBI acceptor through comprehensive molecular, interfacial, and device engineering.

Cell-specific and pH-activatable rubyrin-loaded nanoparticles for highly selective near-infrared photodynamic therapy against cancer.

Spatiotemporal control of singlet oxygen ((1)O2) release is a major challenge for photodynamic therapy (PDT) against cancer with high therapeutic efficacy and minimum side effects. Here a selenium-rubyrin (NMe2Se4N2)-loaded nanoparticle functionalized with folate (FA) was designed and synthesized as an acidic pH-activatable targeted photosensitizer. The nanoparticles could specifically recognize cancer cells via the FA-FA receptor binding and were selectively taken up by cancer cells via receptor-mediated endocytosis to enter lysosomes, in which NMe2Se4N2 was activated to produce (1)O2.

[Spectra characteristics and electroluminescence performance of novel fluorene derivatives with aggregation fluorescence enhancement].

The photoluminescence (PL) spectra and UV-Visible absorption spectra of three novel fluorene derivatives solution containing different triphenylamine (TPA) and tetraphenyl-benzene (TPB) groups were systematically investigated. The PL spectra of the acetone/water solution were tested to analyze the capability of suppression concentration quenching (SCQ). The results showed that when water fraction ranged from 50% to 90%, the spectral irradiance of the mixture was obviously increased.

[Spectral characteristics of white organic light-emitting devices based on phosphorescent system of three iridium chelates].

A white organic light-emitting device (WOLED) with a yellow phosphorescence material, bis[2-(4-tertbutylphenyl) benzothiazolato-N,C2 '] iridium (acetylacetonate) [(t-bt)2Ir(acac)], and two blue phosphorescence materials, iridium(Ill) bis (4', 6'-difluorophenylpyridinato) tetrakis(1-pyrazolyl) borate (FIr6) and bis[(4, 6-difluorophenyl)-pyridinato-N, C2 '] (picolinate) iridium (III) (FIrpic), were fabricated. Stable white emission was realized by using undoped ultrathin yellow emissive layer (EML), two doped blue EMLs together with the proper thickness of an interlayer confining the exciton. The WOLED performed pure white light emission with the Commissions Internationale de l'Eclairage (CIE) coordinates of (0.

Transfer from trap emission to band-edge one in water-soluble CdS nanocrystals.

A simple and rapid route to water-soluble CdS nanocrystals stabilized by citrate was reported, and the transfer of citrate-stabilized CdS NCs from trap emission to band-edge one was studied systematically for the first time. It was found that heating in air, alkaline activation and illumination, all efficiently manipulated surface states of CdS NCs and controlled the emission states, leading to transferring CdS NCs from a broad trap emission (FWHM ~125 nm) to their strong, narrow band-gap emission (FWHM ~25 nm), comparable to that of CdS NCs synthesized by organic routes. Lifetime decay kinetic studies demonstrated that the average lifetimes for CdS NCs before and after transferred were 131.

Aqueous synthesis and characterization of glutathione-stabilized β-HgS nanocrystals with near-infrared photoluminescence.

A simple, rapid and green aqueous approach to near-infrared (NIR)-emitting β-HgS nanocrystals (NCs) was demonstrated for the first time by using glutathione (GSH) as the stabilizer at room temperature. The resulting HgS NCs with zinc blend structure exhibited strong quantum size effect, and the emission peak could be tuned in a wide NIR region from ca. 775 to 1041 nm.

[Electroluminescent performance and spectral characteristics of a novel (t-bt)2Ir(acac) phosphorescent iridium complex].

The photoluminescence (PL) spectra and UV-Visible absorption spectra of a novel yellow phosphor dye of bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2'] iridium (acetylacetonate) denoted as (t-bt)2Ir(acac) were systematically investigated, which were measured in solution and film states with various concentrations. The results showed that the highest PL intensity was achieved when the solution concentration was 3 x 10(-4) mol L(-1), and it decreased dramatically when the concentration kept on increasing because of concentration quenching of the phosphor dye. A red shift for PL spectra and UV-Vis absorption spectra of films compared to those of solutions were found, which is due to the shorter distance, aggregation effect, and stronger interaction of dye molecules in solid state.

In situ synthesis of highly luminescent glutathione-capped CdTe/ZnS quantum dots with biocompatibility.

This paper focuses on the in situ synthesis of novel CdTe/ZnS core-shell quantum dots (QDs) in aqueous solution. Glutathione (GSH) was used as both capping reagent and sulfur source for in situ growth of ZnS shell on the CdTe core QDs. The maximum emission wavelengths of the prepared CdTe/ZnS QDs can be simply tuned from 569 nm to 630 nm.

[Spectral characteristics of novel small molecular fluorene derivative for organic light-emitting device].

Double-layer organic light-emitting devices (OLEDs) based on a blend system of novel small molecule fluorene material 6,6'-(9H-fluoren-9,9-diyl) bis(2,3-bis(9,9-dihexyl-9H-fluoren-2-yl) quinoxaline) (BFLBBFLYQ) and hole transporting material N, N'-biphenyl-N, N'-bis-(3-methylphenyl)-1, 1'-biphenyl-4, 4'-diamine (TPD) were fabricated. The structure of the double-layer device was ITO/BFLBBFLYQ : TPD/tris(8-hydroxyquinolinato) aluminum(Alq)/Mg : Ag. The photoluminescence (PL) spectra of BFLBBFLYQ and TPD were located at 447 and 414 nm, respectively.

[Fluorescence spectra of rubrene dopant for organic light-emitting devices].

The effect of concentration of 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) yellow dye in solution on fluorescence performance was studied through various concentrations. Also the photoluminescence (PL) spectra of rubrene solution with various concentrations were measured to investigate the concentration effect, which is beneficial to obtaining an optimum concentration at maximum PL intensity without concentration quenching. One hand was to focus on the range of concentration for quenching.

[Influence of fluorescent dye ultrathin layer on luminescence spectra in organic light-emitting diodes].

By using an ultrathin dopant dye layer deposited on the top of host materials, the influence of concentration of three fluorescent dyes, dimethylquinacridone (DMQA), 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), and 5,6,11,12-tetraphenylnaphthacene (rubrene), on the luminescence spectra of OLEDs was studied. The characteristic of the brightness-efficiency-bias voltage performance was investigated. The results showed that compared to the conventional doping devices, the devices consisting of ultrathin dye layer exhibited a weak peak originating from host matrix, and the more obvious concentration quenching was existent.

[Spectral characteristics of white organic light-emitting devices based on a novel nitrile fluorescence dye].

A white organic light-emitting device with a blend polymeric emissive system consisting of a novel nitrile fluorescence (2Z, 2'Z)-3, 3'-(1,4-phenylene)bis(2-phenylacrylonitrile) (BPhAN) as dopant and poly(N-vinylcarbazole) (PVK) as host was fabricated. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was introduced into bilayer device as an electron transporting layer (HTL) and a hole blocking layer (HBL), respectively. By adjusting the doping ratio of BPhAN, a series of devices with different concentration proportion of PVK : BPhAN were constructed.

Selective synthesis of CdTe and high luminescence CdTe/CdS quantum dots: the effect of ligands.

This paper describes the selective syntheses of high luminescence CdTe and core-shell CdTe/CdS quantum dots (QDs) in aqueous solution by simple heating refluxing at 100 degrees C. CdTe QDs are prepared by using three kinds of ligands (thioglycolic acid-TGA, tiopronin-TP, and glutathione-GSH) as stabilizer, respectively. The results of refluxing for 10 min to several hours indicate that GSH-capped CdTe QDs have higher photoluminescence quantum yields (QY 54%) than TGA (QY 41%)- and TP (QY 24%)-stabilized CdTe QDs.

[Quantitative determination of pazufloxacin using water-soluble quantum dots as fluorescent probes].

The quantum dots (QDs) synthesized in aqueous solution have more advantages than those synthesized in organic solution, for drugs always act on the biological systems. In addition, the CdTe QDs surface-bound TGA molecules can not only enhance the fluorescence intensity, but also improve the stability of quantum dots, which makes the integrate of quantum dots and the organism easier. The present paper studied on the interaction of CdTe quantum dots, which were synthesized in aqueous solution with pazufloxacin, the forth generation of quinoloines drugs by fluorescence spectrum and absorption spectrum.

Water-soluble CdSe and CdSe/CdS nanocrystals: a greener synthetic route.

We report a new green synthetic route of CdSe and core-shell CdSe/CdS nanoparticles (NPs) in aqueous solutions. This route is performed under water-bath temperature, using Se powder as a selenium source to prepare CdSe NPs, and H(2)S generated by the reaction of Na(2)SH(2)SO(4) as a sulfur source to synthesize core-shell CdSe/CdS NPs at 25-35 degrees C. The synthesis time of every step is only 20 min.

Chlorobenzylidine-calf thymus DNA interaction II: circular dichroism and nuclear magnetic resonance studies.

The binding of chlorobenzylidine to calf thymus DNA has been studied in detail by means of circular dichroism (CD), nuclear magnetic resonance (1H NMR), viscosimetry and denaturation temperature (Tm). Chlorobenzylidine is found to intercalate between base pairs of DNA as evidence by: (1) induced circular dichroism; (2) broadened 1H NMR signals; (3) enhanced viscosity; and (4) increased denaturation temperature of the DNA helix. In addition, Scatchard plot from CD titration data gives a binding constant of 2.

[Regulatory effect of zengmian mixture on T-lymphocyte dysfunction in children with repeated lower respiratory tract infection of both Qi-Yin deficiency type].

Objective: To explore the T-lymphocyte dysfunction in children with repeated infection of lower respiratory tract of both Qi-Yin deficiency type (RIR-QYD) and the immune regulatory effect of zengmian mixture (ZMM), to provide theoretical basis for the effective therapy.

Methods: Peripheral T-lymphocyte subsets and expressions of T-lymphocyte activating related surface molecules (CD3+/HLA-DR+ and CD3+/CD25+, etc.) in children with RIR-QYD, 31 of mild type and 28 of severe type cases, were investigated before administration of ZMM and after treatment of ZMM for 3-6 months (non-infectious stage), using immune fluorescent labelling and flow cytometric technique.