Template-directed Method Research Articles

Self-sacrificing template fabrication of mesoporous CuO micro/nanoplates for photo-Fenton-like oxidation of sulfathiazole

In this study, we offer a simple self-sacrificial template-directed method to prepare mesoporous CuO micro/nanoplates by using copper hydroxide acetate (Cu2(OH)3(CH3COO)·H2O) plates as a template. The as-prepared material was structurally, morphologically, optically and texturally characterized and its excellent catalytic activity in the LED-driven photo-Fenton-like process of sulfathiazole oxidation was demonstrated. Within 90 min, 100 % sulfathiazole degradation and 87.3 % TOC removal were achieved in the presence of H2O2 and visible LED irradiation. Moreover, the degradation of sulfathiazole can still reach 96.1 % after five cycles, which indicates exceptional performance of the catalyst.

Preparation of SiO2 nanotubes and nanoparticles in the presence of L-tartaric acid by sol-gel method and their electrochemical performance for Li-ion batteries

Recently, SiO2 has attracted increasing attention as an anode material for lithium-ion batteries (LIBs) owing to its low cost and high theoretical specific capacity. However, its inherent poor conductivity limits its practical application. To address this issue, nanostructured material design is considered an effective solution. Herein, based on the traditional ammonium tartrate template-directed sol-gel method, we use low-cost and easily available L-tartaric acid in place of D, L-tartaric acid to prepare high-yield silica nanotubes (SNTs) with a thin wall (ca. 50 nm), small diameter (ca. 150 nm), rough surface and open ends, as well as tiny spongy-like silica nanoparticles (SNPs) by adjusting the feeding amount and feeding mode of NH4OH solution. The electrochemical characterization results suggest that the SNTs show better cyclability and rate performance than the SNPs, which maintain a reversible capacity of 741.3 mAh g−1 after 500 cycles at a current density of 0.4 A g−1 and deliver a high rate capacity of 819.4 mAh g−1 at a high current rate of 2 A g−1. The excellent electrochemical performance suggests that hollow one-dimensional hollow nanotubes are more efficient in improving the electrochemical performance of SiO2 than zero-dimensional nanoparticles, and SNTs with thin tube walls and rough surfaces are demonstrated to be fascinating and promising anode materials for LIBs.

Three-Dimensional Porous Cu/Cu2+1O Nanosheet Arrays Promote Electrochemical Nitrate-to-Ammonia Conversion.

The efficiency of electrochemical nitrate (NO3-) reduction to ammonia (NH3) still remains a challenge due to the sluggish kinetics of the complex eight-electron reduction process and competitive hydrogen evolution reaction (HER). Herein, we designed new three-dimensional (3D) porous Cu/Cu2+1O nanosheet arrays (Cu/Cu2+1O NSA) by coupling a template-directed method with in situ electroreduction. Thanks to the 3D porous structure and in-plane heterojunctions, Cu/Cu2+1O NSA can provide abundant active sites and a good interfacial effect, obtaining the maximum Faradaic efficiency (FE) of ammonia (88.09%) and high yield rate of 0.2634 mmol h-1 cm-2, which is higher than that of CuO nanosheets (77.81% and 0.2188 mmol h-1 cm-2) and CuO nanoparticles (34.60% and 0.0692 mmol h-1 cm-2). Experimental results and DFT simulations show that the interface effect of Cu/Cu2+1O can decrease the reaction energy barrier of the key step (*NO to *NOH) and can greatly inhibit the competitive hydrogen evolution reaction, thereby achieving excellent electrocatalytic performance for nitrate-to-ammonia conversion.

Site-selective template-directed synthesis of antibody Fc conjugates with concomitant ligand release.

Template-directed methods are emerging as some of the most effective means to conjugate payloads at selective sites of monoclonal antibodies (mAbs). We have previously reported a method based on an engineered Fc-III reactive peptide to conjugate a radionuclide chelator to K317 of antibodies with the concomitant release of the Fc-III peptide ligand. Here, our method was redesigned to target two lysines proximal to the Fc-III binding site, K248 and K439. Using energy minimization predictions and a semi-combinatorial synthesis approach, we sampled multiple Fc-III amino acid substituents of A3, H5, L6 and E8, which were then converted into Fc-III reactive conjugates. Middle-down MS/MS subunit analysis of the resulting trastuzumab conjugates revealed that K248 and K439 can be selectively targeted using the Fc-III reactive variants L6Dap, L6Orn, L6Y and A3K or A3hK, respectively. Across all variants tested, L6Orn-carbonate appeared to be the best candidate, yielding a degree and yield of conjugation of almost 2 and 100% for a broad array of payloads including radionuclide chelators, fluorescent dyes, click-chemistry reagents, pre-targeted imaging reagents, and some cytotoxic small molecules. Furthermore, L6Orn carbonate appeared to yield similar conjugation results across multiple IgG subtypes. In vivo proof of concept was achieved by conjugation of NODAGA to the PD1/PD-L1 immune checkpoint inhibitor antibody atezolizumab, followed by PET imaging of PD-L1 expression in mice bearing PD-L1 expressing tumor xenograft using radiolabeled [64Cu]Cu-atezolizumab.

Superelastic Cobalt Silicate@Resorcinol Formaldehyde Resin Core-Shell Nanobelt Aerogel Monoliths with Outstanding Fire Retardant and Thermal Insulating Capability.

The practical applications of resorcinol formaldehyde resin (RFR) aerogels are prevented by their poor mechanical properties. Herein, a facile template-directed method is reported to produce macroscopic free-standing cobalt silicate (CS)@RFR core-shell nanobelt aerogels that display superelastic behavior and outstanding thermal insulating and fire-resistant capability. The synthesis relies on the polymerization of RFR on pre-formed CS nanobelts which leads to in situ formation of hydrogel monoliths that can be transformed to corresponding aerogels by a freeze-drying method. The composite nanobelt aerogel can withstand a compressive load of more than 4000 times of its own weight and fully recover after the removal of the weight. It can also sustain 1000 compressive cycles with 6.9% plastic deformation and 91.8% of the maximum stress remaining, with a constant energy loss coefficient as low as 0.16, at the set strain of 30%. The extraordinary mechanical properties are believed to be associated with the structural flexibility of the nanobelts and the RFR-reinforced joints between the crosslinked nanobelts. These inorganic-organic composite aerogels also show good thermal insulation and excellent fire-proof capability. This work provides an effective strategy for fabricating superelastic RFR-based aerogels which show promising applications in fields such as thermal insulation, energy storage, and catalyst support.

Constructing atomically dispersed Snδ+ sites in porous carbon nanosheets to boost lithium-/sodium-storage capability

Nanoscale carbon-supported single atomic metal active centers (Mδ+) have recently caught much attention as a high-efficient catalyst in energy-conversion/-storage fields. Further works extended to employ these materials as the lithium-/sodium-storage anode. Inspired by the progresses, porous carbon nanosheets with abundant Snδ+ sites (Sn-PCNS) are prepared by easy-controllable template-directed method and post carbonization process in this work. Here, atomically dispersed Snδ+ is stabilized mainly by O/N moieties in carbon framework, which can enhance the electron transfer and Li+-/Na+-diffusion kinetics, thus benefiting the Li+-/Na+-storage capabilities. As a result, the Sn-PCNS electrode can deliver a high lithium-storage capacity of 428 mA h g−1 at 10 A g−1 and show a long-term cycling performance for sodium storage at high rate (∼ 120 mA h g−1 at 5 A g−1 after 1000 cycles). This work not only provides a strategy for the preparation of new sheet-like carbon-based nanomaterials, but also offer an opportunity to promote the application of carbon-supported single atomic metal active centers in energy conversion and storage.

Highly conductive tissue-like hydrogel interface through template-directed assembly

Over the past decade, conductive hydrogels have received great attention as tissue-interfacing electrodes due to their soft and tissue-like mechanical properties. However, a trade-off between robust tissue-like mechanical properties and good electrical properties has prevented the fabrication of a tough, highly conductive hydrogel and limited its use in bioelectronics. Here, we report a synthetic method for the realization of highly conductive and mechanically tough hydrogels with tissue-like modulus. We employed a template-directed assembly method, enabling the arrangement of a disorder-free, highly-conductive nanofibrous conductive network inside a highly stretchable, hydrated network. The resultant hydrogel exhibits ideal electrical and mechanical properties as a tissue-interfacing material. Furthermore, it can provide tough adhesion (800 J/m2) with diverse dynamic wet tissue after chemical activation. This hydrogel enables suture-free and adhesive-free, high-performance hydrogel bioelectronics. We successfully demonstrated ultra-low voltage neuromodulation and high-quality epicardial electrocardiogram (ECG) signal recording based on in vivo animal models. This template-directed assembly method provides a platform for hydrogel interfaces for various bioelectronic applications.

Non-stoichiometric Cu2-xSe hollow nanocubes cathodes enabling high-rate capability and ultra-long cyclic stability rechargeable Mg batteries

Rechargeable Mg batteries with the merits of low cost, high safety and environmental compatibility are deemed as promising energy storage techniques for large-scale applications. However, the actual development of rechargeable Mg batteries is constantly hindered by the difficulty of finding suitable electrode materials to accommodate Mg2+. Cu2-xSe has exceptionally high electrical conductivity and its unique crystal structure could be better compatible with Mg2+ cations. Herein, a novel Cu2-xSe hollow nanocube with extraordinarily high conductivity and unique structure was designed and synthesized by facile one-step template-directed selenation reaction methods. The excellent Mg electrochemical performance of Cu2-xSe hollow nanocube cathodes was demonstrated based on rechargeable Mg batteries. The Cu2-xSe NCs provide a high specific capacity of 232.5 mAh g-1 at 100 mA g-1, superior cycling stability over 3700 cycles, and an excellent rate capacity of 163.1 mAh g-1 at 3000 mA g-1. Furthermore, the two-step magnesiation/demagnesiation processes of the Cu2-xSe NC cathodes were revealed, and the accelerating effects of the fast Mg2+ diffusion in the unique hierarchical structure on magnesium storage performance were analyzed. The outcomes of this study not only provide simple methods for fabricating high-performance Cu2-xSe cathodes but also propose valuable insights for exploring conversion-type Mg-storage materials.

Graphene Nanofoam Based Nanomaterials: Manufacturing and Technical Prospects

This article fundamentally reviews progress in the design and manufacturing of three-dimensional (3D) graphene-based nanocomposites for technical applications. The 3D graphene nanostructures have been manufactured using techniques like the template method, chemical vapor deposition, sol-gel, freeze-drying, hydrothermal technique, and other approaches. The nanofoam has been reinforced in polymers to achieve superior structural, morphological, and physical characteristics of the ensuing polymer/graphene nanofoam nanocomposites. The polymer/graphene nanofoam nanocomposites have been manufactured using the approaches like direct template method, in situ technique, infiltration process, and other methods. The 3D nanofoam- and polymer-based nanostructures have shown high specific surface area, suppleness, electron transport, thermal conduction, mechanical resilience, and other physical properties. The technical applications of hierarchical graphene nanofoams have been observed in the fields of radiation shielding, solar cells, supercapacitors, fuel cells, and other applications.

Template-directed growth of Ag nanostructures: soft templates versus hard templates.

Hard template-directed growth methods present a compelling route for the synthesis of Ag nanostructures with precise size control. Meanwhile, soft template methods are effective and flexible for the synthesis of Ag nanostructures with various morphologies. However, the role of the soft template is ambiguous and obviously neglected in hard template-directed growth processes due to the strong confinement effect of the hard template, limiting the diversity of Ag nanostructures that can be obtained. Herein, we design Au nanoframes with deformable head structures as a hard template while using cetyltrimethylammonium chloride as a soft template, to direct the growth of Ag atoms on Au nanobipyramid seeds. When using the Au nanoframes with a closed head, the longitudinal growth of the Ag atoms is clearly limited by the hard template, leading to the formation of thick Ag nanorods with a five-fold twinned structure. The soft template starts to influence the growth process when the head structure of the Au nanoframes becomes hollow. In particular, the confinement effect of the hard template can be completely broken by selectively strengthening the role of the soft template, promoting the production of slender Ag nanorods similar to the results obtained in the absence of the hard template. Our results indicate that the morphology of the Ag nanostructures depends on the competition between the qualitatively confined energies of the hard and soft templates during the template-directed growth process. Moreover, this confined growth mechanism is also verified by the successful construction of various Ag nanostructures. The understanding of the collaborative competition mechanism between the soft and hard templates presents a great opportunity to construct novel Ag nanostructures through a template-directed method.

Electrodeposition of One-Dimensional Nanostructures: Environmentally Friendly Method

During the past decade, nanotechnology has become an active field of research because of its huge potential for a variety of applications. When the size of many established, well-studied materials is reduced to the nanoscale, radically improved or new surprising properties often emerge. There are mainly four types of nanostructures: zero, one, two and three dimensional structures. Among them, one-dimensional (1D) nanostructures have been the focus of quite extensive studies worldwide, partially because of their unique physical and chemical properties. Compared to the other three dimensional structures, the first characteristic of 1D nanostructure is its smaller dimension structure and high aspect ratio, which could efficiently transport electrical carriers along one controllable direction; as a consequence they are highly suitable for moving charges in integrated nanoscale systems. The second characteristic of 1D nanostructure is its device function, which can be exploited as device elements in many kinds of nanodevices. Indeed it is important to note that superior physical properties including superconductivity, enhanced magnetic coercivity and the unusual magnetic state of some 1D nanostructures have been theoretically predicted and some of them have already been confirmed by experiments. In order to attain the potential offered by 1D nanostructures, one of the most important issues is how to synthesize 1D nanostructures in large quantities with a convenient method. Many synthetic strategies, such as solution or vapor-phase approaches, template-directed methods, electrospinning techniques, solvothermal syntheses, self-assembly methods, etc., have been developed to fabricate different classes of 1D nanostructured materials, including metals, semiconductors, functional oxides, structural ceramics, polymers and composites. All the methods can be divided into two categories: those carried out in a gas phase (i.e., “dry processes”) and those carried out in a liquid phase (i.e., “wet processes”). The dry processes include, for example, techniques such as chemical vapor deposition (CVD), physical vapor deposition (PVD), pulse laser deposition (PLD), metal-organic chemical vapor deposition (MOCVD), and molecular beam epitaxy (MBE). In general, these gas phase processes require expensive and specialized equipments. The wet processes include sol-gel method, hydrothermal method, chemical bath deposition (CBD) and electrodeposition. Among the above mentioned methods, electrodeposition has many advantages such as low cost, environmentally friendly, high growth rate at relatively low temperatures and easier control of shape and size. Generally, there are two strategies to produce the 1D nanostructures through the electrochemical process. They are the template-assisted electrodeposition, and the template-free electrodeposition. In this chapter, we will approach the recent progress and offer some prospects of future directions in electrodeposition of 1D nanostructures. Electrodeposition is a simple and flexible method for the synthesis of one-dimensional (1D) nanostructures and has attracted great attention in recent years.

Seminaphthorhodafluor Derivatives Bridged Periodic Mesoporous Organosilicas for Detection of Cu2.

Seminaphthorhodafluor (SNARF) Schiff base (SNARF-SB) bridged periodic mesoporous organosilicas (SSPMOs) with "turn-on" fluorescence enhancement for sensing Cu2+ were synthesized via a template-directed co-condensation method. Small-angle x-ray scattering (SAXS) patterns, high resolution transmission electron microscope (HRTEM) images, and N2 adsorption-desorption isotherms indicated the presence of mesoporous structure in the SSPMOs. FT-IR spectra and 29Si MAS NMR data confirmed the successful incorporation of bridged organic groups in the framework of SSPMOs. The luminous properties that SSPMOs had a selective response to Cu2+ were investigated by UV-Vis absorption spectroscopy and fluorescence spectroscopy. The limit of detection (LOD) was 5.1 × 10-7M and binding stoichiometry was determined 1:1 between SNARF-SB and Cu2+. The fluorescence enhancement of SSPMOs towards Cu2+ was induced by ring-opening of the spirolactam in SNARF-SB in framework of SSPMOs, which was confirmed by FT-IR spectra of SNARF-SB with Cu2+. Moreover, SSPMOs have improved fluorescence lifetimes compared with that of SNARF-SB. Therefore, SSPMOs can be a progressive chemical sensor for Cu2+ due to its high selectivity, recyclability, and stability.

Carbon nanotubes anchored onto hollow carbon for efficient oxygen reduction

The rational design and facile construction of non-noble metal-based electrocatalysts for efficient oxygen reduction reaction (ORR) remain a challenge for the development of clean energy conversion devices. Herein, we synthesized a new type of hierarchical hollow carbon nanomaterials through one-step pyrolysis on bimetallic ZIF-Zn/Co precursors. The obtained hollow N-doped carbon composites, denoted as HNCT-CNTs, are enriched with Co-Nx sites and in-situ formed multi-walled carbon nanotubes (CNTs). Theoretical and experimental studies confirmed that the obtained HNCT-CNT exhibits excellent ORR catalytic activity with a reduced energy barrier for ORR intermediates. Owing to these advantages, the optimal catalyst shows an excellent half-wave potential of 0.85 V, a limiting current density up to 6.36 mA cm−2, a Tafel slope of 58.2 mV dec−1, and robust stability. Furthermore, the assembled Zn-air battery based on HNCT-CNT also displays an open circuit voltage of 1.49 V and a satisfactory power density of 116.56 mW cm−2. This template-directed preparation method opens up an interesting and efficient route to fabricate highly active non-noble metal-doped carbon nanomaterials for a wide range of electrochemical energy applications.

Steam catalytic cracking of crude oil over novel hierarchical zeolite–containing mesoporous silica–alumina core-shell catalysts

The direct conversion of crude oil to basic chemicals was studied over novel core-shell structured ZSM-5 zeolite containing mesoporous silica-alumina (MSA) composites. A template-directed sol-gel method in an alkaline medium was used to prepare a core-shell structured ZSM-5 containing MSA composites employing CTAB as template, tetraethyl orthosilicate (TEOS), and aluminum sulfate. This approach resulted in the formation of a uniform mesoporous silica-alumina shell around the zeolite crystal. The shell thickness (tune in the 8–26 nm range) and its alumina content were controlled by varying the TEOS/zeolite and TEOS/aluminum sulfate ratios. The physicochemical properties and steam catalytic cracking performance of Arab Extra Light (AXL) crude oil were investigated to enhance the yield of C2-C4 light olefins. For comparative study, conventional and mesoporous silica-alumina composites were mixed with kaolin (50%), steam deactivated (810 °C for 6 h) and tested in a fixed-bed reactor operated at 675 °C, residence time of 10 s and steam/oil ratio (g/g) of 0.5. The optimized mesoporous silica-alumina composite Z30 @ MSA (TEOS/zeolite = 0.85 and TEOS/aluminum sulfate = 15.86) had improved textural characteristics, moderate acidity, and AXL crude oil cracking potential at higher conversion (~70%) and selectivity towards light olefins (49.4%) than the unmodified ZSM-5(30). The mesoporous core-shell composite's distinct reaction pattern resulted in the formation of a unique mesoporous silica-alumina core-shell catalyst, which eased the rapid diffusion of desired products from intra-framework channels while inhibiting the formation of coke deposits.

Template-directed synthesis of covalent porphyrin cages andnanorings and their applications

<p indent="0mm">Template-oriented strategy is proven highly effective in constructing complex and orderly structures, which has greatly facilitated the synthesis of complicated porphyrin cages and nanorings. In a typical template method, the metalloporphyrin precursors firstly form pre-organized self-assemblies by means of the coordination interactions between metalloporphyrins and the selected template, and the components are then connected through chemical reactions to provide the final covalent porphyrin cages or nanorings. Although covalent porphyrin cages or nanorings can also be prepared without the use of templates, the template-directed method is obviously more advantageous, especially in the synthesis of highly complicated multi-porphyrin nanorings. In this review, the template-directed synthesis of covalent porphyrin cages and nanorings in recent years and their applications in host-guest chemistry, artificial photosynthesis, biomimetic catalysis and nanomedicine are summarized. Finally, the future prospects are envisaged.

Recent Advances in the Synthesis and Application of Three-Dimensional Graphene-Based Aerogels.

Three-dimensional graphene-based aerogels (3D GAs), combining the intrinsic properties of graphene and 3D porous structure, have attracted increasing research interest in varied fields with potential application. Some related reviews focusing on applications in photoredox catalysis, biomedicine, energy storage, supercapacitor or other single aspect have provided valuable insights into the current status of Gas. However, systematic reviews concentrating on the diverse applications of 3D GAs are still scarce. Herein, we intend to afford a comprehensive summary to the recent progress in the preparation method (template-free and template-directed method) summarized in Preparation Strategies and the application fields (absorbent, anode material, mechanical device, fire-warning material and catalyst) illustrated in Application of 3D GAs with varied morphologies, structures, and properties. Meanwhile, some unsettled issues, existing challenges, and potential opportunities have also been proposed in Future Perspectives to spur further research interest into synthesizing finer 3D GAs and exploring wider and closer practical applications.

Template-directed synthesis of zeolitic imidazolate framework-8 derived Zn–Al layered double oxides decorated on the electrochemically anodized nanoporous aluminum substrate for thin film microextraction of chlorophenols followed by determination with high-performance liquid chromatography

In this work, hierarchical ZIF-8 coated anodized aluminum foil was prepared through in situ template-directed method without addition of any zinc salt. The hierarchical sorbent was synthesized by the formation of the final HZIF-8 on the previously created layered double oxide (LDO) template. The LDO template was created by calcining the firstly in situ prepared desired layered double hydroxide (LDH) precursor coated on the electrochemically anodized porous Al foil in an air atmosphere. The microextraction ability of the extracting device was studied through direct immersion thin film microextraction (DI-TFME). The extracted analytes were quantified by high-performance liquid chromatography equipped by UV detector (HPLC-UV). The present strategy was used for the simultaneous extraction and quantification of four selected chlorophenols (CPs) (as model analyte). The variables of the TFME were optimized using response surface methodology (Plackett-Burman and Box-Behnken design). Under the obtained optimum condition, the prepared film presented acceptable extraction properties including low limits of detection (0.03-0.22 µgL−1), good linear ranges (0.2–200 µgL−1, r2 > 0.9918) and satisfactory reproducibility (relative standard deviation, 3.6 < RSD < 5.8% for one film as inter- and intra-day RSD, 4.8 < RSD < 5.3% for film to film). Moreover, the obtained enrichment factors were in the range of 56-76. The kinetics and adsorption isotherm of the selected analytes adsorption to the prepared sorbent were also investigated. The maximum adsorption capacities of the selected analytes on the prepared sorbent were in the range of 26.4-80.1 mg g−1. The adsorption isotherm obeyed the Langmuir and Freundlich models. Moreover, the adsorption of the selected chlorophenols on the prepared film followed the pseudo-second-order kinetic model. Finally, the HZIF-8 film was utilized for the quantification of selected CPs in different types of water and wastewater samples. The results showed satisfactory relative recoveries (93–102%) and acceptable precisions (3.6 < RSD < 9.2%).

Efficient Electrochemical Production of H2O2 on Hollow N-Doped Carbon Nanospheres with Abundant Micropores.

Electrocatalytic two-electron (2e-) oxygen reduction reaction (ORR) has been regarded as an efficient strategy to achieve onsite H2O2 generation under ambient conditions. However, due to the sluggish kinetics and competitive reaction between 2e- and 4e- ORR, exploring more efficient ORR catalysts with dominant 2e- ORR selectivity is of significance. Herein, hollow N-doped carbon spheres (HNCS) with abundant micropores through a template-directed method are presented. Consequently, the selectivity of the HNCS reaches ∼91.9% at 0.7 V (vs RHE), and the output for H2O2 production is up to 618.5 mmol gcatalyst-1 h-1 in 0.1 M KOH solution. The enhanced performance of HNCS for H2O2 electrosynthesis could be attributed to the hollow structure and heteroatom/defect/pore incorporation. The strategy presented here could shed light on the design of efficient carbon-based materials for improved 2e- ORR.

Water-responsive tough 1D hydrogel with programmable deformations for actuators and chemical sensors

To utilize water-responsive hydrogels in biomedical devices and soft robotics, hydrogels with high response speed and good mechanical properties are required. However, fabrication of such hydrogels remains challenging. In this study, a facile method for producing a one-dimensional (1D) hydrogel with water-responsive programmable deformations was developed. A tough hydrogel fiber with an interpenetrating polymer network based on a biopolymer was synthesized using a template-directed method. A 1D hydrogel that shrinks quickly in contact with water was fabricated by simply stretching and drying the hydrogel fiber under ambient conditions. The fabricated 1D hydrogel exhibited excellent mechanical properties, accurately controlled and programmable deformations, and an extraordinarily high degree of deformation with dimensional changes greater than 300%. Based on such 1D hydrogels, one-way soft actuators, which can be bent or can lift a weight when exposed to water, and a chemical sensing platform, which can detect ethanol in a water–ethanol mixture, were developed.

Hierarchical mesoporous zinc-imidazole dicarboxylic acid MOFs: Surfactant-directed synthesis, pH-responsive degradation, and drug delivery

The surfactant template-directed solvothermal method was applied in the synthesis of hierarchical mesoporous zinc-imidazolate derivative metal–organic framework (mesoMOF), which was then utilized for active loading of cisplatin (cis-Pt). To fabricate mesoMOF, various amounts of the surfactant (cetyltrimethylammonium bromide: 0.1–0.3 g) and linker (citric acid: 0.05–0.15 g) were added to the reaction mixture, which resulted in different particle sizes and morphologies. MesoMOF quality attributes such as Specific surface area (SSA), total porous volume, and Barrett-Joyner-Halenda (BJH) pore diameter were also determined. At the optimum reaction condition, mesoMOF with a high surface area (1859 m2/g), pore diameter (14.13 nm) and total pore volume (0.314 cm3/g) was attained. In the next step, cis-Pt was actively loaded in the mesoMOF with a high loading capacity (28% w/w), which was remarkably superior to the microporous MOF. Interestingly, in mildly acidic pH (5.5), mesoMOF underwent degradation, resulting in a rapid release of cis-Pt. Cell viability and apoptosis induction assays confirmed the superiority of the cis-Pt loaded mesoMOF over free drug in a resistant ovarian tumor cell line (A2780cp). Altogether, due to their tunable size and morphology, pH-responsiveness, and acceptable tolerability in mice, the mesoMOFs can be regarded as an anti-cancer drug delivery system.