Synthesis of HKUST-1 and zeolite beta composites for deep desulfurization of model gasoline

A sensitive dual-signal electrochemiluminescence immunosensor based on Ru(bpy)32+@HKUST-1 and Ce2Sn2O7 for detecting the heart failure biomarker NT-proBNP

A sensitive dual-signal electrochemiluminescence (ECL) immunosensor was proposed based on Ru(bpy)₃²⁺@HKUST-1/TPA and Ce₂Sn₂O₇/K₂S₂O₈ probes for detecting the NT-proBNP biomarker of heart failure. HKUST-1 with a high specific surface area facilitates the loading of more Ru(bpy)₃²⁺, effectively improving the anodic signal intensity, while the emerging Ce₂Sn₂O₇ emitter displays a potential-matching cathodic emission with moderate intensity. Two ECL probes were characterized with field emission scanning electron microscopy, X-ray diffraction, XPS, FT-IR spectroscopy and UV-Vis diffuse reflectance spectroscopy. This dual-signal immunosensor has a wide linear range (5 × 10^-4-1 × 10⁴ ng mL^-1) and a low quantitative detection limit, simultaneously showing high sensitivity, stability and reproducibility, as well as the detection capability of actual serum samples. This dual signal-calibrated immunoassay platform not only reduces the false positive rate of detection results but also provides a promising method for the early diagnosis of heart failure.

Metal-Organic Frameworks for Liquid Phase Applications

In the last two decades, metal-organic frameworks (MOFs) have attracted overwhelming attention. With readily tunable structures and functionalities, MOFs offer an unprecedentedly vast degree of design flexibility from enormous number of inorganic and organic building blocks or via postsynthetic modification to produce functional nanoporous materials. A large extent of experimental and computational studies of MOFs have been focused on gas phase applications, particularly the storage of low-carbon footprint energy carriers and the separation of CO2-containing gas mixtures. With progressive success in the synthesis of water- and solvent-resistant MOFs over the past several years, the increasingly active exploration of MOFs has been witnessed for widespread liquid phase applications such as liquid fuel purification, aromatics separation, water treatment, solvent recovery, chemical sensing, chiral separation, drug delivery, biomolecule encapsulation and separation. At this juncture, the recent experimental and computational studies are summarized herein for these multifaceted liquid phase applications to demonstrate the rapid advance in this burgeoning field. The challenges and opportunities moving from laboratory scale towards practical applications are discussed.

Coupling Structural and Adsorption Properties of Metal-Organic Frameworks: From Pore Size Distribution to Pore Type Distribution

Metal-organic frameworks (MOFs) attract a rapidly growing attention across the disciplines due to their multifarious pore structures and unique ability to selectively adsorb, store, and release various guest molecules. Pore structure characterization and coupling of adsorption and structural properties are imperative for rational design of advanced MOF materials and their applications. The pore structure of MOFs represents a three-dimensional network comprised of several types of pore compartments: interconnected cages and channels distinguished by their size, shape, and chemistry. Here, we propose a novel methodology for pore structure characterization of MOF materials based on matching of the experimental adsorption isotherms to in silico-generated fingerprint isotherms of adsorption in individual pore compartments of the ideal crystal. The proposed approach couples structural and adsorption properties, determines the contributions of different types of pores into the total adsorption, and estimates to what extent the pore structure of the sample under investigation is different from the ideal crystal. The MOF pore structure is characterized by the pore type distribution (PTD), which is more informative than the traditional pore size distribution that is based on oversimplistic pore models. The method is illustrated on the example of Ar adsorption at 87 K on hydrated and dehydrated structures of Cu-BTC, one of the most well-known MOF materials. The PTD determined from the experimental isotherm provides an estimate of the crystal fraction in the sample and the accessibility and degree of hydration of different types of pore compartments. In addition, the PTD determined from the experimental adsorption isotherm is used to predict the isosteric heat of adsorption that provides important information on the specifics of adsorption interactions. The results are found to be in excellent agreement with experimental data. Such detailed information about the pore structure and adsorption properties of practical MOF samples cannot be obtained with currently available methods of adsorption characterization.

Deciphering the Relations between Pore Structure and Adsorption Behavior in Metal-Organic Frameworks: Unexpected Lessons from Argon Adsorption on Copper-Benzene-1,3,5-tricarboxylate

Consistent adsorption characterization of metal-organic frameworks (MOFs) is imperative for their wider adoption in industry and practical applications. Current approaches are based on the conventional intuitive representation of MOF pore space as a regular network of pore compartments (cages and channels), adsorption in which occurs independently according to their geometric dimensions. Here, we demonstrate that this conventional approach is unable to describe even qualitatively the shape of Ar adsorption isotherms on hydrated and dehydrated Cu-BTC structures, one of the most well-known MOF materials. A combination of geometric characterization of MOF crystallographic structure, molecular simulation, and virtual visualization of the adsorption process reveals that the filling of the adjacent pore compartments proceeds in parallel in a complex cooperative fashion. The proposed synergistic approach helps us to understand the relations between pore structure geometric and chemical features and adsorption behavior, laying down a foundation for improved methods for MOF characterization.