The use of liquid gallium as a solvent for catalytic reactions has enabled access to well-dispersed metal atoms configurations, leading to unique catalytic phenomena, including activation of neighbouring liquid atoms and mobility-induced activity enhancement. To gain mechanistic insights into liquid metal catalysts, here we introduce a GaSn0.029Ni0.023 liquid alloy for selective propylene synthesis from decane. Owing to their mobility, dispersed atoms in a Ga matrix generate configurations where interfacial Sn and Ni atoms allow for critical alignments of reactants and intermediates. Computational modelling, corroborated by experimental analyses, suggests a particular reaction mechanism by which Sn protrudes from the interface and an adjacent Ni, below the interfacial layer, aligns precisely with a decane molecule, facilitating propylene production. We then apply this reaction pathway to canola oil, attaining a propylene selectivity of ~94.5%. Our results offer a mechanistic interpretation of liquid metal catalysts with an eye to potential practical applications of this technology.

Stereoisomerism, stemming from the spatial orientation of components in molecular structures, plays a decisive role in nature. While the unconventional bonding found in mechanically interlocked molecules gives rise to unique expressions of stereochemistry, the exploration of their stereoisomers is still in its infancy. Sequence isomerism, characterized by variations in the ordering of mechanically interlocked components in catenanes and rotaxanes, mirrors the sequence variations found in biological macromolecules. Herein, we report the use of artificial molecular pumps for the precise and simple production of sequentially isomeric hetero[3]rotaxanes. Utilizing redox-driven pumping cassettes with different rings, we have synthesized two hetero[3]rotaxane isomers in high isolated yields from two [2]rotaxanes. This research represents a significant advance in sequential molecular assembly, paving the way for the development of sophisticated, functionalized, mechanically interlocked materials.

Having showcased intriguing features in a vast range of catalytic applications, liquid metals (LMs) are contin-uously ticking boxes of pathways that are conventionally only associated with transitional metals. Herein, we report a gallium-ethylene glycol system where gallium is utilized to interact and break down organic bonds. Ethylene glycol is selected as a model organic compound, as it has been extensively studied for the reformation mechanisms and the potential to produce hydrogen gas. With mechanical agitation applied to the LM-based reaction system, we establish an in-situ monitoring approach for the gaseous products and also perform a se-ries of characterizations on the post-reaction mixture. We reveal that the hydrogen gas production from the system is continuous and highly selective. Gaseous alkanes and alkenes are also observed in the output. Our analyses demonstrate that gallium induces structural reformations of ethylene glycol following a complex pathway. The process generates methyl, aldehyde, carbonyl, and other groups. We further reveal the formation of polymer products with repeating methylene groups in the system. The process for reforming ethylene glycol signifies the capability of LMs to efficiently break down organic bonds. As such, this study provides a platform to explore environment-friendly and alternative strategies for hydrogen production and organic transformation toward valuable products.

Many different types of inorganic materials are processed into nano/microparticles for medical utilization. The impact of selected key characteristics of these particles, including size, shape, and surface chemistries, on biological systems, is frequently studied in clinical contexts. However, one of the most important basic characteristics of these particles, their density, is yet to be investigated. When the particles are designed for drug delivery, highly mobile macrophages are the major participants in cellular levels that process them in vivo. As such, it is essential to understand the impact of particles' densities on the mobility of macrophages. Here, inorganic particles with different densities are applied, and their interactions with macrophages studied. A set of these particles are incubated with the macrophages and the outcomes are explored by optical microscopy. This microscopic view provides the understanding of the mechanistic interactions between particles of different densities and macrophages to conclude that the particles' density can affect the migratory behaviors of macrophages: the higher the density of particles engulfed inside the macrophages, the less mobile the macrophages become. This work is a strong reminder that the density of particles cannot be neglected when they are designed to be utilized in biological applications.

Liquid metal-electrolyte can offer electrochemically reducing interfaces for the self-deposition of low-dimensional nanomaterials. We show that implementing such interfaces from multiprecursors is a promising pathway for achieving nanostructured films with combinatory properties and functionalities. Here, we explored the liquid metal-driven interfacial growth of metal tellurides using eutectic gallium-indium (EGaIn) as the liquid metal and the cation pairs Ag+-HTeO2+ and Cu2+-HTeO2+ as the precursors. At the EGaIn-electrolyte interface, the precursors were reduced and self-deposited autogenously to form interconnected nanoparticle networks. The deposited materials consisted of metal telluride and tellurium with their relative abundance depending on the metal ion type (Ag+ and Cu2+) and the metal-to-tellurium ion ratios. When used as electrode modifiers, the synthesized materials increased the electroactive surface area of unmodified electrodes by over 10 times and demonstrated remarkable activity for model electrochemical reactions, including HexRu(III) responses and dopamine sensing. Our work reveals the promising potential of the liquid metal-templated deposition method for synthesizing complex material systems for electrochemical applications.

Owing to recent advances in mass spectrometry (MS), tens to hundreds of proteins, lipids, and small molecules can be measured in single cells. The ability to characterize the molecular heterogeneity of individual cells is necessary to define the full assortment of cell subtypes and identify their function. We review single-cell MS including high-throughput, targeted, mass cytometry-based approaches and antibody-free methods for broad profiling of the proteome and metabolome of single cells. The advantages and disadvantages of different methods are discussed, as well as the challenges and opportunities for further improvements in single-cell MS. These methods is being used in biomedicine in several applications including revealing tumor heterogeneity and high-content drug screening.

Eutectic alloys have long been investigated for their unique properties such as single point melting temperature, homogenous structures, and uniform distribution of phases. In this work, we synthesized and characterized two low melting temperature liquid metal alloys. Eutectic alloys of indium-tin-bismuth (Field's metal) and Field's metal-like alloy with traces of zinc (0.4 wt%) were studied through a series of structural, thermal, microstructural, and mechanical tests. The in vitro biocompatibility of the alloys was assessed to investigate their potential application as bioimplants. These low melting point alloys (similar to 62 degrees C and similar to 60 degrees C for Field's metal and the alloy with zinc, respectively) were utilized to address one of the major issues faced by the conventional use of bioimplants, which is the invasive surgery. We provide a proof-of-concept utilizing the combination of induction heating with the Field's metal-based alloys with suitable melting points. The approach enabled a contactless melting and extraction for the non-invasive removal of the bioimplant mimic from a polymer matrix, that can be potentially translated to the human body. We believe that this approach will provide fundamental insights for future biomedical applications and the design of liquid metal based non-invasive implants. (C) 2022 Elsevier Ltd. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A photoswitchable ligand based on azobenzene is self-assembled with palladium(II) ions to form a [Pd2(E-L)4]4+ cage. Irradiation with 470 nm light results in the near quantitative switching to a monomeric species [Pd(Z-L)2]2+. The assembled structures improve the selectivity of photoswitching towards the metastable isomer and increase its thermal lifetime.

This chapter discusses applications of conductive polymers and their nanocomposites in the removal and remediation of environmental pollutants. Due to the presence of reactive heteroatoms on the conductive polymers’ backbone, different functionalized conductive polymers and conductive polymer-based nanocomposites can be synthesized and utilized in different pollutant removal and remediation techniques. Applications of these materials in adsorption, contaminant degradation, and membrane separation for the removal and remediation of pollutants have been researched. To this end, pure conductive polymers, conductive copolymers, and their nanocomposites are separately considered in each section. Unique features as well as the pros and cons of conductive polymer-based materials utilized in each removal and remediation technique are also highlighted.

Liquid metal (LM) catalysts have been demonstrated to accelerate chemical reactions, providing an intriguing route to fine chemical synthesis with immense technological implications. Herein, we explore gallium-based LMs as catalysts to promote the oxidative self-polymerization of natural polyphenols, an emerging class of natural building blocks for surface functionalization with diverse biochemical properties. The oxidative polymerization of polyphenols, triggered by eutectic alloy of gallium and indium, results in nanocoatings with remarkably high reaction kinetics. The oxidative polymerization occurs in a wide pH range including an acidic environment-a condition previously unexplored for the deposition of phenolic coatings. The LM triggers the generation of highly active radical species from the oxidant causing the rapid oxidation of the polyphenols and their subsequent deposition on a range of different substrates. We further show that the LM-based catalytic system addresses several other limitations of existing coating methods including a narrow pH range, substrate specificity (precursor-dependent), and low coating uniformity. Finally, we demonstrate that the phenolic nanocoatings obtained from the acidic pH environment have excellent antioxidant and antibacterial properties without requiring any post-functionalization step. This process for creating phenolic nanocoatings may find applications in a wide range of industries, food science, and biomedicine.

A “stage-1” intercalated film has been made by the ion exchange of “cationic C60” (pyrrolidinium-functionalised C60, C60(Py)n+) into centimetre-wide, micrometre-thick air-dried graphene oxide (G-O) films composed of tens of thousands of layers of stacked/overlapping G-O platelets, denoted [C60(Py)n+]G-O films. Spontaneous intercalation by ion exchange of one layer of cationic C60 between adjacent G-O layers expands the interlayer spacing of the films from 0.74 nm to 1.46 nm. The films remain intact in water and various organic solvents, which is likely due to a strong affinity between C60(Py)n+ and G-O. Membranes made of the films showed a 6.8 times faster water vapour permeation rate (allowing the vapour to transport through the membrane almost freely) and a 10.5 times faster liquid water permeation rate than G-O membranes. Heating the films at 2000 °C under applied pressure or at 2700 °C without physical confinement converted them into highly graphitised structures.

The advent of chip technology and microfluidics has largely impacted the area of analytical chemistry towards development of more efficient, cost-effective, user- and environmentally friendly analytical devices. So far, diverse analytical platforms based on various device designs have been developed for different analytical applications and the area is still growing very quickly. Considering sample preparation/extraction as one of the most important steps of an analytical assay, microfluidic sample preparative devices have been emerged. These devices have been widely developed over the past decades paving a new way towards efficient analyte isolation and facile integration with various detection methods, while keeping matrix effect, analysis cost, and user-intervention at minimum. Such extensive development is mainly due to the fascinating features of microfluidic devices such as lower amounts of required reagents and samples, faster analysis, more feasibility of integration and automation, as well as providing desirable functionalities through innovation in device design. Herein, we intend to provide a comprehensive overview on exploitation of microfluidic devices in sample extraction covering all aspects of design, fabrication, operation, and different extraction methods as well as the challenges and developing motifs for future studies. (C) 2021 Elsevier B.V. All rights reserved.

Herein, the removal of Hg2+ from environmental water samples was carried out using a novel nanoadsorbent based on magnetite nanoparticles coated by a thioglycerol-intercalated layered double hydroxide. The prepared material was characterized using scanning electron microscopy equipped with an energy dispersive X-ray analyzer and Fourier transform infrared spectrometry. The effective parameters of the removal procedure were identified and optimized through the one-variable-at-a-time method. Under the optimal conditions, the removal characteristics of the synthesized adsorbent including selectivity, distribution coefficient, and loading capacity were calculated in the presence of some interfering ions. The removal efficiency of 94.98% together with the distribution coefficient of 5.00 × 105 mL g-1 and loading capacity of 480.69 mg g-1 showed the considerable capability of this novel adsorbent in the selective removal of Hg2+ from aqueous samples. To evaluate the performance of the synthesized adsorbent in the removal of Hg2+ from environmental water samples, the removal of the desired analyte was carried out using four different real samples. The removal procedures were conducted at the analyte concentration levels of 10.0 and 50.0 mg L-1 for each aqueous sample. The obtained results showed that the removal efficiency was in the range of 91.99-94.97%, which confirmed the high performance of the synthesized adsorbent in the removal of Hg2+ from real samples. Furthermore, the relative standard deviation of as low as 4.18-6.17% showed the acceptable repeatability of this method.

Applications of electrochemical detection methods in microfluidic paper-based analytical devices (μPADs) has revolutionized the area of point-of-care (POC) testing towards highly sensitive and selective quantification of various (bio)chemical analytes in a miniaturized, low-coat, rapid, and user-friendly manner. Shortly after the initiation, these relatively new modulations of μPADs, named as electrochemical paper-based analytical devices (ePADs), gained widespread popularity within the POC research community thanks to the inherent advantages of both electrochemical sensing and usage of paper as a suitable substrate for POC testing platforms. Even though general aspects of ePADs such as applications and fabrication techniques, have already been reviewed multiple times in the literature, herein, we intend to provide a critical engineering insight into the area of ePADs by focusing particularly on the practical strategies utilized to enhance their analytical performance (i.e. sensitivity), while maintaining the desired simplicity and efficiency intact. Basically, the discussed strategies are driven by considering the parameters potentially affecting the generated electrochemical signal in the ePADs. Some of these parameters include the type of filter paper, electrode fabrication methods, electrode materials, fluid flow patterns, etc. Besides, the limitations and challenges associated with the development of ePADs are discussed, and further insights and directions for future research in this field are proposed.

Magnetic dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction coupled with gas chromatography/mass spectrometry was applied for the quantitative analysis of phenazopyridine in urinary samples. Magnetic dispersive solid-phase extraction was carried out using magnetic graphene oxide nanoparticles modified by poly(thiophene-pyrrole) copolymer. The eluting solvent of this step was used as the disperser solvent for the dispersive liquid-liquid microextraction procedure. To reach the maximum efficiency of the method, effective parameters including sorbent amount, adsorption time, type and volume of disperser and extraction solvents, pH of the sample solution, and ionic strength as well as desorption time, and approach were optimized, separately. Characterization of the synthesized sorbent was studied by utilizing infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis. Calibration curve was linear in the range of 0.5-250 ng/mL (R-2 = 0.9988) with limits of detection and quantification of 0.1 and 0.5 ng/mL, respectively. Intra-and interday precisions (RSD%, n = 3) of themethod were in the range of 4.6-5.4% and 4.0-5.5%, respectively, at three different concentration levels. Under the optimal condition, this method was successfully applied for the determination of phenazopyridine in human urine samples. The relative recoveries were obtained in the range of 85.0-89.0%.

In this study, a polydopamine-functionalized multi-walled carbon nanotube was utilized in an efficient pipette-tip micro-solid phase extraction followed by gas chromatography-mass spectrometry for determination of two organophosphorus pesticides called malathion and parathion. All the effective parameters were optimized using a one variable at-a-time protocol. Under the optimal conditions, broad calibration curves were obtained with the linearity in the range between 0.30-200 ngmL(-1). Preconcentration factors as high as 42.7 and 47.3 for malathion and parathion, respectively, were obtained along with the relative standard deviations (RSD%) lower than 6.37%. Real samples analysis was carried out using the optimized technique for quantitative analysis of the target analytes in environmental water samples. Relative recoveries in the range between 89.37-101.22% show the capability of the method in real sample analysis.

A novel metal-organic framework called MFU-4 l was synthesized from ZnCl2 and 1H-1,2,3-triazolo[4,5-b][4′,5′-i])dibenzo[1,4]dioxin. MFU-4 l was characterized and is shown to be a viable sorbent for spin-column micro-solid phase extraction of 4-chlorophenol, 2,3-dichlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Following extraction and elution with methanol, the chlorophenols were quantified by a GC-MS instrument. Various parameters affecting adsorption and desorption were optimized by the one variable at-a-time method. The main feature of the utilized metal-organic framework is its outstanding performance in ultratrace extraction of the target analytes due to the different amino groups existed in the linker structure. Under optimal conditions, the calibration plots are linear in the 0.5–400 μg kg−1 concentration range for water samples, and from 1.0–400 μg kg−1 for soil samples. The respective limits of detection are 0.10 and 0.50 μg kg-1 for water and soil samples, respectively. On top of that, limits of detections are lower than 0.10 and 0.50 μg Kg−1 for water and soil samples, respectively. Inter-day and intra-day relative standard deviations were in the range of 4.4–7.8% for the selected chlorophenols. Preconcentration factors are in the range of 26.3–29.6 for aqueous samples. The method was used to analyze soil and environmental water samples.

Hollow-fiber liquid-phase microextraction (HF-LPME) and electromembrane extraction (EME) are miniaturized extraction techniques, and have been coupled with various analytical instruments for trace analysis of heavy metals, drugs and other organic compounds, in recent years. HF-LPME and EME provide high selectivity, efficient sample cleanup and enrichment, and reduce the consumption of organic solvents to a few micro-liters per sample. HF-LPME and EME are compatible with different analytical instruments for chromatography, electrophoresis, atomic spectroscopy, mass spectrometry, and electrochemical detection. HF-LPME and EME have gained significant popularity during the recent years. This review focuses on hollow fiber based techniques (especially HF-LPME and EME) of heavy metals and pharmaceuticals (published 2017 to May 2019), and their combinations with atomic spectroscopy, UV-VIS spectrophotometry, high performance liquid chromatography, gas chromatography, capillary electrophoresis, and voltammetry.

In the present study, an electrospun composite of polyamide-graphene oxide-polypyrrole was synthesized. The characterization of the synthesized material was accomplished using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR). FESEM images showed uniform and beadles nanofibers. The composite was employed as a novel sorbent for spin-column micro solid phase extraction to determine parabens in milk samples. Addition of graphene oxide and polypyrrole into the polymeric network of polyamide significantly improves the extraction efficiency of the electrospun sorbent due to providing the possibility of various interactions with the target analytes such as hydrogen bonding, hydrophobic and pi-pi stacking. All effective parameters on the efficiency of both adsorption and desorption steps were optimized. These parameters were pH of sample solution (5.0), sorbent amount (20 mg), type and volume of desorption solvent (200 mu L of methanol), number of cycles (7 and 14) and centrifugation speed (600 and 500 rpm) of both adsorption and desorption steps. Under the optimal conditions, the calibration plots were linear within the range of 10-1000,15-1000, and 20-1000 ng mL(-1) for methyl paraben, ethyl paraben and propyl paraben, respectively. Limits of detection were obtained lower than 7.0 ng mL(-1) by HPLC-UV. Intra- and inter-assay relative standard deviations were less than 8.6% and 5.8%, respectively. Finally, the method was successfully applied for determination of parabens in some milk samples and good recoveries were obtained within the range of 81.7-97.8%. The results demonstrated good efficiency of the synthesized electrospun composite nanofibers as the packing material for spin-column micro solid phase extraction. (C) 2019 Elsevier B.V. All rights reserved.