Self-assembled Cyclodextrin Metal-Organic Frameworks on Graphene Oxide as Filter Membrane for Tracelevel Naringin Pre-enrichment before Analysis

A green,renewable composite was designed and fabricated based on self-assembly of cyclodextrin metal-organic framework(CD-MOF)on graphene oxide(GO).Then,the GO@CD-MOF was embedded in 0.45μm PTFE membrane to produce a dual-functional membrane which could carry out sample enrichment by capturing naringin molecules.The membrane filter was further improved by investigating the effects of the experimental parameters including amount of GO@CD-MOF,enrichment time and elution solvent on enrichment efficiency of naringin.Further,the present method had been successfully applied to citrus sample and obtained satisfied recovery value(79.7%-100.3%).Moreover,the extraction of naringin can be achieved for 2 min,and GO@CD-MOF loaded membrane can be reused at least for 5 times.The results demonstrate that the fabrication of the novel filter membrane based on GO@CD-MOF is a fast,simple and reliable,and possesses great potential in the determination of naringin from real samples by dual-function of separation and enrichment.

Tailoring the separation performance of a carbon nanotube-based mixed matrix membrane decorated with metal–organic framework

Synthesis of mixed matrix membranes(MMM)using carbon nanotubes(CNTs)has shown great prospects for achieving excellent selective separation because of its special structure.Nevertheless,the preparation of highly selective MMM faces challenges,which is attributed to the obstacles encountered by CNTs dispersion in polymer matrix and elimination of interface defects.A novel CNT-based composite decorated with metal–organic framework(MOF)was synthesized and applied to the preparation of MMM.MOF was post modified,and then carboxyl groups were inserted on the outer surface of CNTs.The synthetic MMM(Cu-MOF-en@MWCNT)not only has selective adsorption on dyes,but also has selective photodegradation on dyes.The method of using CNTs to wrap the outside of MOF has great potential in dye separation.The performance of MMM was further improved by decorating MOF on the filler to improve the selectivity to the designated dye.

Surface-Oriented Assembly of Cyclodextrin Metal-Organic Framework Film for Enhanced Peptide-Enantiomers Sensing

Oriented metal-organic framework(MOF)films are attracting great attention due to their fascinating physicochemical properties and unique functionalities.Here,we report an[110]-oriented biomolecularγ-cyclodextrin(γCD)MOF film with arrayed CD channels running perpendicular to the substrate surface.This sophisticated architecturewas realized by combining liquid phase epitaxial layer-by-layer(lbl)methods with aγCD-based thiol self-assembled monolayer(SAM)functionalized surface.This first demonstration of the lbl method for MOF growth from aqueous conditions yielded oriented,highly homogeneous,and chiralγCD-SURMOFs(surfacecoordinated MOFs)with tunable thickness.Using a quartz crystal microbalance(QCM)to monitor adsorption of biomolecules,we demonstrated thatγCD-SURMOF provides highly-efficient recognition of tripeptide enantiomers(Tyr-(L-Ala)-Phe vs Tyr-(D-Ala)-Phe),clearly outperformingγCD(SH)_(8) SAMs as well as polycrystalline,mixed-orientationsγCDMOF film.The presence of well-alignedγCD-channels enables highly efficient transport channels with large adsorption capacity and fast loading,along with high enantioselectivity.In addition,the fast and highly specific loading rates allow for the realization of highly specific sensors for biomolecules with short response times.

Achieving High CO_(2)Photoreduction Activity by Conductive Crosslinks of Metal–Organic Framework

Fast photogenerated charge migration is crucial for the improvement of photocatalytic performance,but its deliberate modulation is difficult.This work presents two Zr-based metal–organic framework catalysts,GDUT-8 and GDUT-8-Ox,for photocatalytic CO_(2)reduction.Specifically,thiophene pendants in GDUT-8 were coupled covalently via Scholl reaction to give GDUT-8-Ox,a catalyst with at least two orders of magnitude(up to 6.1×10^(−3)S cm^(−1))enhanced conductivity and faster transport of photogenerated carriers during photocatalysis.Furthermore,from GDUT-8 to GDUT-8-Ox,stronger ligand-to-cluster charge transfer with pronounced light absorption extension was observed.As a result,GDUT-8-Ox exhibited the highest photocatalytic CO_(2)-to-HCOO−conversion rate(1725μmol g^(−1)h^(−1))to date,in the absence of photosensitizer,as well as turnover number,turnover frequency,and quantum efficiency much higher than GDUT-8.This work presents an unprecedented strategy to accelerate the photogenerated carrier transport of photocatalysts.

交联环糊精金属有机骨架负载甲氨蝶呤缓释微粒的制备及体内外评价

甲氨蝶呤(methotrexate,MTX)注射给药的半衰期短,毒副作用大。为了改善MTX注射给药的缺陷,本研究将MTX装载在交联环糊精金属有机骨架(crosslinked cyclodextrin metal-organic framework,COF)中,得到载药微粒MTX@COF,采用溶剂蒸发法将阳离子脂质材料(2,3-二油酰基-丙基)-三甲胺[(2,3-dioleyl-propyl)-trimethylamine,DOTAP]包裹在MTX@COF表面,MTX@COF@DOTAP的微粒形态没有显著改变,但具有不同的表面电荷特征。以水和磷酸盐缓冲液(pH 7.4)为释放介质考察缓释微粒的体外释放,并通过大鼠药代动力学评价其体内释放特征。体外释放结果显示,在水中MTX、MTX@COF和MTX@COF@DOTAP于6 h的累积释放量分别为92.70%、36.31%和18.19%;在磷酸盐缓冲液中MTX、MTX@COF和MTX@COF@DOTAP于4 h的累积释放量分别为90.82%、79.37%和58.30%,表明MTX@COF可显著延缓MTX的释放,经DOTAP修饰后的MTX@COF可进一步延缓MTX的释放。大鼠药代动力学研究结果显示,皮下注射MTX@COF@DOTAP组与MTX@COF组及MTX组相比,其平均滞留时间MRT_((0-t))和达峰时间T_(max)明显延长,且MTX@COF@DOTAP组的药时曲线下面积[AUC_((0-t))]是MTX组的1.8倍。本研究制备的MTX@COF@DOTAP微粒经皮下注射给药具有一定的缓释效果,并提高了MTX的生物利用度,为MTX的新剂型开发提供一个新的思路。

Novel CD-MOF NIR-II fluorophores for gastric ulcer imaging

Gastric ulcers are one of the most common stomach diseases that often accompanied by inflammation,congestion,edema,scar tissue formation,and pyloric obstruction.Fiberoptic endoscopy and X-ray analysis of the upper GI tract have become the diagnostic procedure of choice for patients.However,conventional diagnosis technology is either invasive or radioactive.Herein,a novel CD-MOF NIR-II fluorophore(GPs-CH1055)was developed.The relative fluorophore intensity was largely consistent at various media and pH buffers,and it can swell into gel particles in solvents and be completely expelled from the gastrointestinal tract without being assimilated.GPs-CH1055 has been further evaluated in vivo,and exhibited strong retention effect on the gastric ulcer sites,bright NIR-II signals with high spatial and temporal resolution.Therefore,GPs-CH1055 shows great promise for realizing real-time gastric ulcer imaging and diagnosis.