Organic polystyrene and inorganic silica double shell protected lead halide perovskite nanocrystals with high emission efficiency and superior stability

The practical application of all-inorganic semiconductor lead halide perovskite nanocrystals(LHP NCs)has been limited by their poor stability.Recently,a lot of research on core-shell structure has been done to improve the stability of perovskite NCs,but the effect was far from the application requirements.Herein,we,for the first time,report a convenient approach to synthesize organic-inorganic double shell CsPbBr_(3)@SiO_(2)@polystyrene(PS)NCs with an inter-core of CsPbBr_(3),the intermediate layer of SiO_(2)shell,and outmost PS shell.Particularly,the CsPbBr_(3)@SiO_(2)@PS NCs maintained more than 90%of their initial photoluminescence(PL)intensity under one month's ultraviolet lamp irradiation or in 85℃ and 85%relative humidity(RH)condition.The white-light-emitting-diodes(WLEDs)were fabricated by encapsulating commercial InGaN chip with CsPbBr_(3)@SiO_(2)@PS NCs and K2SiF6:Mn^(4+)(KSF:Mn^(4+))phosphor with a luminous efficacy of~100 lm/W at 20 mA current and a color gamut of 128%of the National Television Standards Committee(NTSC)standard.In addition,these WLEDs still maintain 91%of the initial luminous efficacy after 1200 h of continuous lighting.These results demonstrated that double shell-protected CsPbBr_(3)perovskite NCs have great potential in the field of WLEDs.

Synthesis and immunological evaluation of Mincle ligands-based antitumor vaccines

The development of novel adjuvants constitutes a new strategy for the research of tumor vaccines.Immunomodulatory molecule adjuvants are one of the novel adjuvants that can effectively stimulate the pattern recognition receptors to activate the downstream pathways of immune cells.However,there are few studies on immunomodulatory molecular adjuvants associated with C-type lectin.It has been reported that GlcC_(14)C_(18)is a Mincle ligand with a relatively simple structure and strong adjuvant activity in vivo.Herein,we coupled GlcC_(14)C_(18)with MUC1 glycopeptide and evaluated its immune effect.In addition,we also synthesized α-GlcC_(14)C_(18)-MUC1 and β-GlcC_(14)C_(18)-MUC1 based on the two configurations of GlcC_14C_(18)and compared their immune effects.The results show that both of the two configurations of the vaccine have a good immune effect,but to a certain extent,the immune effect of β-GlcC_(14)C_(18)-MUC1 is better than that of α-GlcC_(14)C_(18)-MUC1.

Synthesis and optical properties of highly efficient Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+)blue phosphor for full-spectrum white-light-emitting diodes:The role of Li_(2)CO_(3)flux

Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na_(3)KMg_(7)(PO_(4))6:Eu^(2+)phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li_(2)CO_(3)as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV(400 nm)diode chip excitation.The practical Eu^(2+)concentration is also enhanced by using Li_(2)CO_(3)as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL thermal stability,namely retains 94%integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu^(2+)blue,Sr_(2)SiO_(4):Eu^(2+)green,CaAlSiN_(3):Eu^(2+)red phosphors,and a 400 nm NUV diode chip.It shows a high color rendering index of=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu^(2+)is a promising blue phosphor for full-spectrum WLED based on NUV diode chips.

Synthesis of NaYF_(4):20% Yb^(3+),2% Er^(3+),2% Ce^(3+)@NaYF_(4) nanorods and their size dependent uptake efficiency under flow condition

Lanthanide doped fluorescent nanoparticles have gained considerable attention in biomedical applications.However,the low uptake efficiency of nanoparticles by cells has limited their applications.In this work,we demonstrate how the uptake efficiency is affected by the size of nanoparticles under flow conditions.Using the same size NaYF_(4):20%Yb^(3+),2%Er^(3+),2%Ce^(3+)(the contents of rare earths elements are in molar fraction)nanoparticles as core,NaYF_(4):20%Yb^(3+),2%Er^(3+),2%Ce^(3+)@NaYF_(4) core-shell structured nanorods(NRs)with different sizes of 60-224 nm were synthesized by thermal decomposition and hot injection method.Under excitation at 980 nm,a strong upconversion green emission(541 nm,^(2)H_(11/2)→^(4) I_(15/2) of Er^(3+))is observed for all samples.The emission intensity for each size nanorod was calibrated and is found to depend on the width of NRs.Under flow conditions,the nanorods with 96 nm show a maximum uptake efficiency by endothelial cells.This work demonstrates the importance of optimizing the size for improving the uptake efficiency of lanthanide-doped nanoparticles.

Alum colloid encapsulated insideβ-glucan particles enhance humoral and CTL immune responses of MUC1 vaccine

We have developed a MUC1 antigen-based antitumor vaccine loaded on alum colloid encapsulated insideβ-glucan particles(GP-Al).The constructed vaccine induced strong MUC1 antigen specific Ig G antibody titers and enhanced CD^(8+)T cells cytotoxic effect to kill tumor cells.These results indicated that GP-Al can be served as an efficient delivery system and adjuvant for the development of cancer vaccines especially small molecule antigens based cancer vaccines.

Precursor chemistry towards highly efficient and phase-stable red emitting CsPbI_(3) perovskite nanocrystals

All-inorganic cesium lead halide perovskite nanocrystals(CsPbX_(3),X=Cl,Br,I)have attracted considerable scientific and technological interest due to their precise bandgap tunability,high color purity and efficient luminescence.Nevertheless,their poor stability in harsh conditions such as moisture,ultraviolet(UV)light irradiation and high temperature,is a major obstacle for their further commercial applications.Herein,by simply using a new type of precursor,namely“HPbX_(3)”(X=Cl,Br,I),we can achieve the coordination equilibrium for Pb precursors during reaction and obtain high-quality perovskite nanocrystals with tremendously enhanced luminous efficiency and chemical stability based on hot-injection method.The prepared a-CsPbb nanocrystals exhibit an extremely high photoluminescence quantum yield of 96%and keep stable in air for more than two months without any post-synthesis treatment.Moreover,stability evaluations under UV light irradiation,water or thermal impact are also performed and the results show substantially improved stability of these nanocrystals as compared with the samples prepared using traditional Pbl_(2) as precursor.Through temperature-dependent(10-300 K)steady and transient spectral analysis combined with compositional measurements,it is revealed that the lower structural defect density,which is guaranteed by abundant halogen when using HPbX3 as precursor,is the most important reason for such performance enhancement.

Enhancing the immune response and tumor suppression effect of antitumor vaccines adjuvanted with non-nucleotide small molecule STING agonist

Vaccine adjuvants have been widely used to enhance the immunogenicity of the antigens and elicit long-lasting immune response.However,only few vaccine adjuvants have been approved by the FDA for human use so far.Therefore,there is still an urgent need to develop novel adjuvants for the potential applications in clinical trials.Herein,non-nucleotide small molecule STING agonist di ABZI was employed to construct glycopeptide antigen based vaccines for the first time.Immunological evaluation indicated di ABZI not only enhanced the production of antibodies and T cell immune responses,but also inhibited tumor growth in tumor-bearing mice in glycopeptide-based subunit vaccines.These results indicated that di-ABZI demonstrates a high potential as adjuvant for the development of cancer vaccines.