Synergistic Interaction between Metal Single-Atoms and Defective WO3- x Nanosheets for Enhanced Sonodynamic Cancer Therapy.

Although metal single-atom (SA)-based nanomaterials are explored as sonosensitizers for sonodynamic therapy (SDT), they normally exhibit poor activities and need to combine with other therapeutic strategies. Herein, the deposition of metal SAs on oxygen vacancy (OV)-rich WO3- x nanosheets to generate a synergistic effect for efficient SDT is reported. Crystalline WO3 and OV-rich WO3- x nanosheets are first prepared by simple calcination of the WO3·H2O nanosheets under an air and N2 atmosphere, respectively. Pt, Cu, Fe, Co, and Ni metal SAs are then deposited on WO3- x nanosheets to obtain metal SA-decorated WO3- x nanocomposites (M-WO3- x). Importantly, the Cu-WO3- x sonosensitizer exhibits a much higher activity for ultrasound (US)-induced production of reactive oxygen species than that of the WO3- x and Cu SA-decorated WO3, which is also higher than other M-WO3- x nanosheets. Both the experimental and theoretical results suggest that the excellent SDT performance of the Cu-WO3- x nanosheets should be attributed to the synergistic effect between Cu SAs and WO3- x OVs. Therefore, after polyethylene glycol modification, the Cu-WO3- x can quickly kill cancer cells in vitro and effectively eradicate tumors in vivo under US irradiation. Transcriptome sequencing analysis and further molecular validation suggest that the Cu-WO3- x-mediated SDT-activated apoptosis and TNF signaling pathways are potential drivers of tumor apoptosis induction.

Iron Porphyrin as a Cytochrome P450 Model for the Degradation of Dye.

Organic dyes are widely used in the textile, biological, medical and other fields. However, a serious environmental problem has appeared because of the presence of organic dyes in industrial aqueous effluents. Thus, the efficient treatment of organic dyes in industrial wastewaters is currently in real demand. The current study investigated the oxidative degradation of the organic dye gentian violet by meso-tetra(carboxyphenyl) porphyriniron(III), [FeIII(TCPP)] as a cytochrome P450 model and iodosylbenzene (PhIO) as an oxidant at room temperature. The degradation reaction was monitored by UV-vis absorption spectroscopy via the observation of UV-vis spectral changes of the gentian violet. The results showed that the efficiency of catalyzed degradation reached more than 90% in 1 h, indicating the remarkable oxidative degradation capacity of the [FeIII(TCPP)]/PhIO system, which provided an efficient approach for the treatment of dyeing wastewater.

Anionic Porous Zn-Metalated Porphyrin Metal-Organic Framework with PtS Topology for Gas-Phase Photocatalytic CO2 Reduction.

Presented here are the synthesis and gas-phase photocatalytic CO2 reduction of an anionic porous Zn-metalated porphyrin metal-organic framework (MOF) induced by an ionic liquid. The desired CO2 affinity and deep conduction band position of the MOF catalyst provide strong kinetic and thermodynamic advantages for photocatalytic CO2 to CH4 conversion with high selectivity (∼70%) in H2O vapor.

Intercalation-Activated Layered MoO3 Nanobelts as Biodegradable Nanozymes for Tumor-Specific Photo-Enhanced Catalytic Therapy.

The existence of natural van der Waals gaps in layered materials allows them to be easily intercalated with varying guest species, offering an appealing strategy to optimize their physicochemical properties and application performance. Herein, we report the activation of layered MoO3 nanobelts via aqueous intercalation as an efficient biodegradable nanozyme for tumor-specific photo-enhanced catalytic therapy. The long MoO3 nanobelts are grinded and then intercalated with Na+ and H2 O to obtain the short Na+ /H2 O co-intercalated MoO3-x (NH-MoO3-x ) nanobelts. In contrast to the inert MoO3 nanobelts, the NH-MoO3-x nanobelts exhibit excellent enzyme-mimicking catalytic activity for generation of reactive oxygen species, which can be further enhanced by the photothermal effect under a 1064 nm laser irradiation. Thus, after bovine serum albumin modification, the NH-MoO3-x nanobelts can efficiently kill cancer cells in vitro and eliminate tumors in vivo facilitating with 1064 nm laser irradiation.

High loading of Mn(ii)-metalated porphyrin in a MOF for photocatalytic CO2 reduction in gas-solid conditions.

A high loading of Mn(ii)-metalated porphyrin was achievable in a 2D porphyrin-based Mn-MOF induced by an ionic liquid. The excellent stability, sufficient redox potential, atomically dispersed porphyrin Mn(ii) sites, desired CO2 affinity, high visible light-harvesting and efficient charge separation, endow this MOF with the overall photocatalytic conversion of CO2 to CH4 in gas-solid conditions.

Activating Layered Metal Oxide Nanomaterials via Structural Engineering as Biodegradable Nanoagents for Photothermal Cancer Therapy.

Layered metal oxides including MoO3 and WO3 have been widely explored for biological applications owing to their excellent biocompatibility, low toxicity, and easy preparation. However, they normally exhibit weak or negligible near-infrared (NIR) absorption and thus are inefficient for photo-induced biomedical applications. Herein, the structural engineering of layered MoO3 and WO3 nanostructures is first reported to activate their NIR-II absorption for efficient photothermal cancer therapy in the NIR-II window. White-colored micrometre-long MoO3 nanobelts are transformed into blue-colored short, thin, defective, interlayer gap-expanded MoO3-x nanobelts with a strong NIR-II absorption via the simple lithium treatment. The blue MoO3-x nanobelts exhibit a large extinction coefficient of 18.2 L g-1 cm-1 and high photothermal conversion efficiency of 46.9% at 1064 nm. After surface modification, the MoO3-x nanobelts can be used as a robust nanoagent for photoacoustic imaging-guided photothermal therapy to achieve efficient cancer cell ablation and tumor eradication under irradiation by a 1064 nm laser. Importantly, the biodegradable MoO3-x nanobelts can be rapidly degraded and excreted from body. The study highlights that the structural engineering of layered metal oxides is a powerful strategy to tune their properties and thus boost their performances in given applications.

Ionic liquid induced highly dense assembly of porphyrin in MOF nanosheets for photodynamic therapy.

Two-dimensional (2D) metal-organic framework (MOF) nanosheets have emerged as a new member of 2D nanomaterials for molecular sieving, energy conversion and storage, catalysis and biomedicine. In this paper, a highly dense assembly of porphyrin achievable in porphyrin-integrated MOF nanosheets induced by an ionic liquid is obtained by sonication exfoliation of its bulk crystals. The 2D layered structure MOF, [BMI]2[Ca3(H2TCPP)2(µ2-OH2)2(H2O)2] (1), was firstly prepared by using the ionic liquid assisted synthetic method (H6TCPP = meso-tetra(carboxyphenyl) porphyrin, BMI = 1-butyl-3-methylimidazolium). The laminated layers in 1 clearly indicate a weak interlayer non-covalent interaction but a strong metal-carboxylate bonding within the layers, which facilitates the exfoliation of 1 to form 2D MOF nanosheets (1 NSs). Powder X-ray diffraction (PXRD), high-resolution transmission electron microscopy (HR-TEM) and fast Fourier transform (FFT) patterns revealed that 1 NSs could maintain their crystalline structure after exfoliation. These MOF nanosheets exhibited excellent aqueous dispersibility, biodegradability and high cytotoxicity under light irradiation against MCF-7 cells.

Metallic 1T Phase Enabling MoS2 Nanodots as an Efficient Agent for Photoacoustic Imaging Guided Photothermal Therapy in the Near-Infrared-II Window.

Transition metal dichalcogenide (TMD) nanomaterials, specially MoS2 , are proven to be appealing nanoagents for photothermal cancer therapies. However, the impact of the crystal phase of TMDs on their performance in photoacoustic imaging (PAI) and photothermal therapy (PTT) remains unclear. Herein, the preparation of ultrasmall single-layer MoS2 nanodots with different phases (1T and 2H phase) is reported to explore their phase-dependent performances as nanoagents for PAI guided PTT in the second near-infrared (NIR-II) window. Significantly, the 1T-MoS2 nanodots give a much higher extinction coefficient (25.6 L g-1  cm-1 ) at 1064 nm and subsequent photothermal power conversion efficiency (PCE: 43.3%) than that of the 2H-MoS2 nanodots (extinction coefficient: 5.3 L g-1  cm-1 , PCE: 21.3%). Moreover, the 1T-MoS2 nanodots also give strong PAI signals as compared to negligible signals of 2H-MoS2 nanodots in the NIR-II window. After modification with polyvinylpyrrolidone, the 1T-MoS2 nanodots can be used as a highly efficient agent for PAI guided PTT to effectively ablate cancer cells in vitro and tumors in vivo under 1064 nm laser irradiation. This work proves that the crystal phase plays a key role in determining the performance of nanoagents based on TMD nanomaterials for PAI guided PTT.

Amphiphilic calix[4]arenes as a highly selective gas chromatographic stationary phase for aromatic amine isomers.

Efficient separation of aromatic amine isomers is a challenging issue in chemical industry and environmental analysis. Here we report the use of p-amino-tetradecyloxy-calix[4]arene (C4A-NH2) as a novel stationary phase for gas chromatographic (GC) separations. The statically coated C4A-NH2 capillary column showed a high column efficiency of 4332 plates/m for a 0.25 mm ID column and medium polarity. The C4A-NH2 stationary phase exhibited an excellent separation performance both for aromatic amine isomers and a complex mixture of aliphatic analytes with a wide ranging polarity, showing distinct advantages over the commercial polysiloxane stationary phases via diversified molecular interactions covering H-bonding, π-π, van der Waals interactions and shape-fitting selectivity. The retention mechanisms of aromatic amine isomers on C4A-NH2 column were further investigated by quantum chemistry calculations. In addition, the C4A-NH2 column showed good column repeatability with relative standard deviation (RSD) values of 0.03%-0.07% for run-to-run, 0.10%-0.27% for day-to-day and 2.6%-5.7% for column-to-column, respectively, and thermal stability up to 240℃.

Performance and selectivity of lower-rim substituted calix[4]arene as a stationary phase for capillary gas chromatography.

This work presents the investigation of p-tert-butyl(tetradecyloxy)calix[4]arene (C4A-C10) as stationary phase for capillary gas chromatographic (GC) separations. The statically-coated C4A-C10 capillary column showed weak polarity and column efficiency of 2566 plates per m determined by n-dodecane at 120 °C. Impressively, the C4A-C10 column exhibited extremely high resolving capability for a wide range of analytes from nonpolar to polar, including n-alkanes, esters, ketones, aldehydes, alcohols and bromoalkanes. Most importantly, the C4A-C10 column exhibited an excellent separation performance for positional, structural and cis-/trans-isomers. Among them, the column displayed advantageous resolving capability over the commercial polysiloxane stationary phase for aromatic amine isomers. Moreover, the C4A-C10 column showed good column repeatability with RSD values below 0.06% for run-to-run, 0.12-0.27% for day-to-day and 2.8-5.3% for column-to-column.

Performance of palm fibers as stationary phase for capillary gas chromatographic separations.

Herein we report the first example of exploring bio-based materials, palm fibers (PFs), as a stationary phase for capillary gas chromatographic separations. The PFs capillary column was fabricated by the sol-gel coating method and showed a weak polar nature and high column efficiency over 4699 plates per m for n-dodecane, naphthalene and n-octanol. Importantly, the column exhibited high selectivity and resolving capability for more than a dozen mixtures covering a wide-ranging variety of analytes and isomers. In addition, it was applied for the determination of isomer impurities in real samples, proving its good potential for practical gas chromatographic analysis.

Structural diversity and photocatalytic properties of Cd(II) coordination polymers constructed by a flexible V-shaped bipyridyl benzene ligand and dicarboxylate derivatives.

Hydrothermal reactions of Cd(OAc)2·2H2O with a flexible V-shaped bipyridyl benzene ligand and five benzenedicarboxylic acid derivatives gave rise to five new coordination polymers i.e., [Cd(1,4-BDC)(bpmb)(H2O)]n (1), {[Cd(1,3-BDC)(bpmb)]·0.125H2O}n (2), [Cd2(5-Me-1,3-BDC)2(bpmb)2]n (3), [Cd(5-NO2-1,3-BDC)(bpmb)(H2O)]n (4) and [Cd(5-OH-1,3-BDC)(bpmb)(H2O)]n (5) (bpmb = 1,3-bis(pyridine-3-ylmethoxy)benzene, 1,4-H2BDC = 1,4-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, 5-Me-1,3-H2BDC = 5-methyl-1,3-benzenedicarboxylic acid, 5-NO2-1,3-H2BDC = 5-nitro-1,3-benzenedicarboxylic acid, 5-OH-1,3-H2BDC = 5-hydroxy-1,3-benzenedicarboxylic acid). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Compound 1 is a two-fold interpenetrating network showing the coexistence of polyrotaxane and polycatenane characters. Compounds 2 and 3 exhibit similar 2D (3,5)-connected (4(2)·6(7)·8)(4(2)·6) nets in which the bpmb ligands work as lockers in interlocking 1D [Cd(1,3-BDC/5-Me-1,3-BDC)]n chains. Compound 4 shows a 2D 4-connected (6(6)) sandwich-like structure with differently oriented [Cd(5-NO2-1,3-BDC)]n chains. Compound 5 is a 3D supramolecular pcu net based on a 1D ladder-shaped chain. These results suggest that the substituted positions of carboxylate groups and changes in substituted R groups in the 5-position of BDC ligands have significant effect on the final structures. These compounds exhibited relatively good photocatalytic activity towards the degradation of methylene blue (MB) in aqueous solution under UV irradiation. Moreover, solid-state photoluminescence properties of 1-5 were also investigated.

The structural diversity and photoluminescent properties of cadmium thiophenedicarboxylate coordination polymers.

Two series of Cd(II) coordination polymers (CPs), {[Cd(bimm)2(H2O)2][(3,4-tdc)2][H2O]2}n (1a), [Cd(3,4-tdc)(bimb)]n (2a), [Cd(3,4-tdc)(bimpy)(H2O)]n (3a) and [Cd(2,3-Htdc)2(bimm)2]n (1b), {[Cd(2,3-tdc)(bimb)](H2O)}n (2b), [Cd(2,3-tdc)(bimpy)(H2O)]n (3b) where H2tdc = thiophenedicarboxylic acid, bimm = 1,2-bis(imidazol-1'-yl)methane, bimb = 1,2-bis(imidazol-1'-yl)butane and bimpy = 3,5-bis(imidazol-1'-yl)pyridine, have been synthesized by using Cd(II) acetate with H2tdc and N-donor ligands under hydrothermal conditions. Two related isomeric thiophenedicarboxylic acids were chosen to examine the positional isomeric effect on the construction of these CPs with distinct dimensionality and connectivity. The structure of 1a is a one-dimensional (1D) cationic double chain further forming a two-dimensional (2D) supramolecular network via hydrogen-bonding interactions, while 1b exhibits a neutral double chain structure. Interestingly, a three-dimensional (3D) 4-connected cds network for 2a as well as a 1D neutral double chain structure for 2b were obtained in the presence of bimb. When the rigid tripodal bimpy was introduced, isomorphous 3a and 3b with 3D (3,5)-connected (6(2)·8) (6(7)·8(3)) nets were constructed. The structural diversity of 1a-2b mainly stems from the positional isomeric effect of thiophenedicarboxylate, while 3a and 3b are well regulated by rigid bimpy. Moreover, the thermal stability and photoluminescence of 1a-3b are investigated.

Multi-dimensional transition-metal coordination polymers with 5-nitro-1,2,3-benzenetricarboxylic acid exhibiting ferro-/antiferromagnetic interactions.

Six transition metal coordination polymers, [Cu(3)(nbta)(2)(bipy)(2)(H(2)O)(2)] x 2 H(2)O (1), [Cu(3)(nbta)(2)(bpp)(2)(H(2)O)(2)] x 2 H(2)O (2), [Co(3)(nbta)(2)(bipy)(3)(H(2)O)(2)] x 2 H(2)O (3), [Co(3)(nbta)(2)(bpp)(2)(H(2)O)(2)] (4), [Ni(2)(Hnbta)(2)(bipy)(2)(H(2)O)(2)] (5) and [Ni(3)(nbta)(2)(bpa)(3)(H(2)O)(2)] x 2 H(2)O (6) (H(3)nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, bipy = 4,4'-bipyridine, bpa = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane), have been hydrothermally synthesized by the reactions of Cu(II), Co(II) and Ni(II) salts with H(3)nbta in the presence of dipyridyl-type co-ligands, respectively. Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and TG analyses. Compounds 1-4 and 6 exhibit 3D pillared-layer structures while compound 5 has a 2D layer. The nbta(3-) ligands in the 2D carboxylate layer motifs of 1-4 and 6 connect transition metal ions in different coordination modes, and the dipyridyl-type co-ligands in compounds 1-4 and 6 serve as the pillar between the 2D layers, creating 3D open frameworks. From a topologic point of view, complex 1, 2 and 4 present 4-connected 3D coordination frameworks with the topologies of (4(2) x 6(2) x 8(2)) (6(2) x 7(2) x 8(2)) (4(2) x 6(2) x 7 x 8), (6(4) x 8(2)) (4(2) x 6(4)) (4(2) x 6(4)) and (4 x 6(4) x 8)(4(4) x 6(2))(4(3) x 6(3)) respectively. Complex 3 shows a (4,5)-connected 3D network with (4(2) x 6(7) x 8)(6(4) x 8(2))(4(2) x 6(4)) topology. Whereas the structure of 5 is a 2D (4,4) net due to the partially deprotonated H(3)nbta ligand existed. Complex 6 features a 3D (4,5)-connected framework with (4 x 6(8) x 8) (6(5) x 8) (4 x 6(5)) topology, also exhibiting the intriguing helical motif. The variable-temperature magnetic susceptibility studies reveal antiferromagnetic interactions between Cu(II) or Co(II) ions in 1, 2, 3, 4 and ferromagnetic interactions between Ni(II) ions for 5 and 6, respectively.