Immobilization of Metal Nanoparticles to an Ultrathin Two-Dimensional Conjugated Metal-Organic Framework for Synergistic Electrocatalysis.

Metal-organic frameworks (MOFs) have been considered as promising hosts for immobilizing ultrafine metal nanoparticles (MNPs) due to their high surface area and porosity. However, electrochemical applications of such emerging composites are severely limited by the poor electrical conductivity and large size of the MOFs. Herein, we report the general synthesis of incorporating various MNPs into a conjugated MOF ultrathin nanosheet (Cu-TCPP UNS) matrix, which not only prevents agglomeration and restricts the growth of MNPs but also benefits the exposure of active sites and the transport of electrons.

Sterically Crowded Donor-Rich Imidazole Systems as Hole Transport Materials for Solution-Processed OLEDs.

Imidazole, being an interesting dinitrogenic five-membered heterocyclic core, has been widely explored during the last several decades for developing various fascinating materials. Among the different domains where imidazole-based materials find wide applications, the area of optoelectronics has seen an overwhelming growth of functional imidazole derivatives developed through remarkable design and synthesis strategies. The present work reports a design approach for integrating bulky donor units at the four terminals of an imidazole core, leading to the development of sterically populated imidazole-based molecular platforms with interesting structural features.

Tuning the Liquid Crystallinity and Electroluminescence via Sulfonation of S-Annulated Perylene Tetraester.

This study presents a comparative analysis of S-annulated perylene tetraester (PTE-S) and its sulfone (PTE-SO) analogue. This sulfone modification reduced melting point and stabilized a room temperature columnar rectangular (Col) phase in contrast to its parent PTE-S which showed a crystalline behaviour at room temperature. This molecular design also leads to red-shifted absorbance and emission in comparison to PTE-S, along with a tuning of photoluminescence from sky blue to green, achieving an impressive quantum yield of 85 %.

Automation and Computerization of (Bio)sensing Systems.

Sensing systems necessitate automation to reduce human effort, increase reproducibility, and enable remote sensing. In this perspective, we highlight different types of sensing systems with elements of automation, which are based on flow injection and sequential injection analysis, microfluidics, robotics, and other prototypes addressing specific real-world problems. Finally, we discuss the role of computer technology in sensing systems.

Are Most Micrometer Droplets (>10 μm) Wasted in Electrospray Ionization? An Insight from Real-Time High-Speed Imaging.

Electrospray ionization (ESI) is one of the main techniques used in mass spectrometry (MS) of nonvolatile compounds. ESI is a disordered process, in which a large number of polydisperse droplets are projected from a fluctuating Taylor cone and jet protruding ESI emitter. Here, we disclose a system for sectioning electrospray plumes to discrete packets with millisecond and submillisecond lifetime, which are introduced to the MS orifice, one at a time.

Observation of Protein Unfolding during pH Ramp Evoked by Lipase-Catalyzed Ester Hydrolysis.

Studies of protein folding often involve offline experimental methods such as titrating protein samples with denaturants or equilibrating them in the presence of denaturants. Here, we demonstrate an online analytical approach in which the protein structure is perturbed by a pH ramp evoked by immobilized lipase-catalyzed ester hydrolysis. Changes in the tertiary structure of the protein in response to a pH ramp (from approximately 6.

Rationally heteroarylated pyridines as hole transport materials for OLEDs.

The advancement in developing highly efficient hole transport materials for OLED devices has been a challenge over the past several years. For an efficient OLED device, there should be an efficient promotion of charge carriers from each electrode and effective confinement of triplet excitons in the emissive layer of the phosphorescent OLED (PhOLED). Thus, the development of stable and high triplet energy hole transport materials is in urgent demand for high-performing PhOLED devices.

In Search of Hosts for Blue OLEDs: Computational Design and Experimental Validation.

Considering the difficulties associated with the conventional 'trial and error' method for a complete analysis of a giant molecular space, we took the aid of computational pathway (DFT) in screening a large space search of 780 (12×13×5) molecules to search for a host for the blue emitter. The selection process was completed in three Tiers with the conditions of highest theoretical triplet energy (>2.81 eV), aligned HOMO/LUMO levels w.

Rapid Acid/Base Switching in Flow Injection Analysis and Isocratic Elution Liquid Chromatography with Mass Spectrometric Detection for Improved Sensitivity.

Ion signals in electrospray ionization (ESI) mass spectrometry (MS) are affected by addition of acid or base. Acids or bases are typically added to samples to enhance detection of analytes in positive- or negative-ion mode, respectively. To carry out simultaneous monitoring of analytes with different ionogenic moieties by ESI-MS, a rapid acid/base switching system was developed.

Tuning Electrospray Ionization with Low-Frequency Sound.

Electrospray ionization (ESI) mass spectrometry (MS) is one of the key techniques used in biomolecular analysis nowadays. It relies on formation of polydisperse microdroplets, which undergo desolvation and liberate ions to the gas phase. Here we demonstrate low-frequency-sound-modulated ESI for analysis of biomolecules.

Precise immunological evaluation rationalizes the design of a self-adjuvanting vaccine composed of glycan antigen, TLR1/2 ligand, and T-helper cell epitope.

Sialyl-Tn (STn), overexpressed on various tumors, has been investigated for its application in anti-cancer vaccine therapy. However, Theratope, an STn-based vaccine, failed in the phase III clinical trial due to poor immunogenicity and epitope suppression by the foreign carrier protein. We therefore developed a self-adjuvanting STn based-vaccine, a conjugate of clustered STn (triSTn) antigen, TLR1/2 ligand (PamCSK), and T-helper (Th) cell epitope, and found that this three-component self-adjuvanting vaccine effectively resulted in the production of anti-triSTn IgG antibodies.

Recent Advances in Nanomaterial-based Optical Biosensors as Potential Point-of-Care Testing (PoCT) Probes in Carcinoembryonic Antigen Detection.

For the past decades, several cancer biomarkers have been exploited for rapid and accurate prognosis or diagnosis purposes. In this review, the optical biosensor is targeted for carcinoembryonic antigen (CEA) detection. The CEA level is a prominent parameter currently used in clinical cases for the prognosis of cancer-related diseases.

Ring rotation of ferrocene in interlocked molecules in single crystals.

This work describes unique molecular motions of ferrocene-containing interlocked molecules observed by single-crystal X-ray crystallography. The rotational flexibility of ferrocene is achieved using combinations of ferrocene-tethered ammonium and 30-membered ring dibenzo-crown ether. By contrast, ferrocene was locked in the complex with an 18-membered ring dibenzo-crown ether and CHCl.

Influence of Prednisolone and Alendronate on the Mineralization of Zebrafish Caudal Fin.

Dysregulated balance between bone resorption and formation mediates the onset and progression of osteoporosis. The administration of prednisolone is known to induce osteoporosis, whereas alendronate is commonly used to reverse the process. However, the assessment of the effects of such medicines on the nanostructure of bone remodeling and mechanical properties remains a major technical challenge.

Investigation of the - structures and isomerization of oligoprolines by using Raman spectroscopy and density functional theory calculations: solute-solvent interactions and effects of terminal positively charged amino acid residues.

Using low-wavenumber Raman spectroscopy in combination with theoretical calculations solid-state density functional theory (DFT)-D3, we studied the vibrational structures and interaction with solvent of poly-l-proline and the oligoproline P12 series. The P12 series includes P12, the positively charged amino acid residue (arginine and lysine) N-terminus proline oligomers RP11 and KP11, and the C-terminus P11R and P11K. We assigned the spring-type phonon mode to 74-76 cm bands for the PPI and PPII conformers and the carbonyl group ring-opening mode 122 cm in the PPI conformer of poly-l-proline.

Please Avoid Plotting Analytical Response against Logarithm of Concentration.

This perspective highlights a malpractice in handling calibration data sets. It refers to relating analytical response with logarithm of concentration, fitting such a data set with linear function, and deriving method characteristics from the slope of that function. A distinction is made between this malpractice and the proper use of logarithmic plots in representation of calibration data sets.

Biocompatible quantum dot-antibody conjugate for cell imaging, targeting and fluorometric immunoassay: crosslinking, characterization and applications.

Quantum dots (QDs) are important fluorescent probes that offer great promise for bio-imaging research due to their superior optical properties. However, QDs for live cell imaging and the tracking of cells need more investigation to simplify processing procedures, improving labeling efficiency, and reducing chronic toxicity. In this study, QDs were functionalized with bovine serum albumin (BSA) a chemical linker.

Sulfur-doped graphene quantum dot-based paper sensor for highly sensitive and selective detection of 4-nitrophenol in contaminated water and wastewater.

4-Nitrophenol (4-NP) is a promulgated priority pollutant, which can cause a negative impact on human health. The development of a direct and effective technique for the rapid detection and screening of 4-NP is, therefore, of urgent need. In this study, the blue luminescent sulfur-doped graphene quantum dots (S-GQDs) with a size of 1-5 nm are fabricated using a one-step pyrolysis procedure in the presence of citric acid and 3-mercaptosuccinic acid.

Red Phosphorus Potassium-Ion Battery Anodes.

Phosphorus (P) possesses the highest theoretical specific capacity (865 mA h g) among all the elements for potassium-ion battery (PIB) anodes. Although Red P (RP) has intrinsic advantages over its allotropes, including low cost and nontoxicity, and simpler preparation, it is yet unknown to effectively activate it into a high-performance PIB anode. Here, high-performance RP PIB anodes are reported.

Effect of conjugation and aromaticity of 3,6 di-substituted carbazoles on triplet energy and the implication of triplet energy in multiple-cyclic aromatic compounds.

It is well-known that short conjugation is needed to obtain a high triplet energy. Carbazole has 3 fused rings and yet it has a high triplet energy. In order to illuminate the reason behind this, we synthesized a range of carbazole derivatives with substitution at the 3,6-positions.

Enabling high solubility of ZnO in TiO₂ by nanolamination of atomic layer deposition.

Zn-doped TiO2 nanotubes were fabricated by nanolaminated packing of alternating layers of TiO2 and ZnO by atomic layer deposition (ALD) using a polycarbonate (PC) membrane as a template. With 400 cycles of ALD, the nanotubes with a thickness of 28 nm and an outer diameter of 220 nm were obtained after removing the PC membrane by annealing at 450 °C. The doping concentration of ZnO in TiO2 depends on the precursor cycle ratio of ZnO to TiO2.

Gold-catalyzed formal [4π + 2π]-cycloadditions of propiolate derivatives with unactivated nitriles.

Gold-catalyzed hetero-[4π + 2π]-cycloadditions of -butyl propiolates with unactivated nitriles are described; the resulting 6-1,3-oxazin-6-ones are not easily accessible conventional methods. This new finding enables a one-pot gold-catalyzed synthesis of highly substituted pyridines through sequential gold-catalyzed reactions of -butyl propiolates with nitriles, and then with electron-deficient alkynes in the same solvent. The utility of these [4 + 2]-cycloadditions is further expanded with various aldehydes, ketones and 2-phenyloxetane, yielding satisfactory yields of cycloadducts.

Gold-catalyzed reactions of propargylic esters with vinylazides for the synthesis of Z- or E-configured buta-1,3-dien-2-yl esters.

Gold-catalyzed synthesis of buta-1,3-dien-2-yl esters by the reaction of propargyl esters with vinylazides is described; the reaction mechanism is postulated to involve a vinyl attack of vinylazides at alkenyl gold carbenes.

Thermosetting resins with high fractions of free volume and inherently low dielectric constants.

This work demonstrates a new class of thermosetting resins, based on Meldrum's acid (MA) derivatives, which have high fractions of free volume and inherently low k values of about 2.0 at 1 MHz. Thermal decomposition of the MA groups evolves CO2 and acetone to create air-trapped cavities so as to reduce the dielectric constants.

Non-stoichiometric W(18)O(49-x)S(x) nanowires for wide spectrum photosensors with high internal gain.

This study reports successful synthesis of non-stoichiometric single-crystal W18O49-xSx nanowires for photosensors with a high absorption rate (>83%) across a wide spectrum (300-2000 nm), a high internal gain (G = 10(6)-10(7)) and a relatively fast response time (approximately 1-3 s). In addition, the correlation between the photoconductivity gain (G) and the surface-to-volume ratio of non-stoichiometric single-crystal W18O49-xSx nanowires was studied. The surface-to-volume ratio and non-stoichiometric material of W18O49-xSx contributed to the photoconductivity gain; hence, the nanowires are favorable for photosensor devices.