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We firstly report magnetic metal–organic frameworks for selective enrichment and exclusion of proteins for MALDI-TOF MS analysis. Fe3O4@MIL-100(Fe) nanoparticles were achieved by step-by-step assembly on poly(acrylic acid) modified Fe3O4. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIPs) were applied for selective enrichment of proteins in MALDI-TOF MS analysis for the first time. MIPs were achieved simply via immobilization of template lysozyme (Lyz) on core–shell magnetic nanoparticles and self-polymerization of dopamine (DA). [ABSTRACT FROM AUTHOR]

The reliable identification and quantitation of phosphorylated amino acids, peptides and proteins is one of the key challenges in contemporary bioanalytical research, an area of particular interest when attempting to diagnose and treat diseases at an early stage. We have developed a synthetic probe for targeting phosphorylated amino acids, based on core–shell submicron-sized particles consisting of a silica core, coated with a molecularly imprinted polymer (MIP) shell. The MIP layer contains a fluorescent probe crosslinker which binds selectively to phosphorylated tyrosine (pY) moieties with a significant imprinting factor (IF) and responds with a "light-up" fluorescence signal. The bead-based ratiometric detection scheme has been successfully transferred to a microfluidic chip format and its applicability to rapid assays has been exemplarily shown by discriminating a pY-terminating oligopeptide against its non-phosphorylated counterpart. Such miniaturised devices could lead to an automated pY or pY N-terminated peptide measurement system in the future. The setup combines a modular microfluidic system for amino acid derivatisation, extraction (by micropillar co-flow) and selective adsorption and detection with the fluorescent MIP core–shell particle probes. A miniaturised optical assembly for low-light fluorescence measurements was also developed, based on miniaturised opto-electronic parts and optical fibres. The emission from the MIP particles upon binding of pY or pY N-terminated peptides could be monitored in real-time. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication and application of a complex electrode – Nafion film coating ferrocenylalkanethiol (FcC11SH) and encapsulated glucose oxidase (GOD) on a gold electrode. FcC11SH is employed as a mediator enabling the electron transfer between GOD and the electrode, GOD is encapsulated in polyacrylamide gel to improve the stability of the enzyme, and the Nafion film is coated on the modified electrode to eliminate interferents such as ascorbic acid, uric acid and acetaminophen in amperometric glucose detection. It is noticed that such a complex electrode exhibits excellent catalytic activity for glucose oxidation, and preserves the native structure of GOD and therefore its enzymatic activity. The encapsulated GOD retains more than 80% of its original biocatalytic activity even after 24 days, much longer than that of naked GOD molecules attached directly to the electrode. The oxidation peak current at the modified electrode shows a linear relationship with the glucose concentration in the range from 0.05 to 20 mM with a detection limit of 2.4 μM. In addition, the electrode displays a rapid response and good reproducibility for glucose detection, and has been successfully employed for glucose detection in blood plasma samples. [ABSTRACT FROM AUTHOR]

Revealing the “structure–property” relationship is nontrivial for the application of materials. The magnetic configurations of FeGe are strongly dependent on the internal structures and positions of Fe and Ge atoms, e.g., B20-type cubic phase configuring into magnetic skyrmions. Although endotaxial FexGe islands on (001)Ge substrate can be obtained with a dynamically controlled growth process, it is not possible to obtain the crystal structural information from conventional approaches, such as X-ray diffraction or 2D electron diffractions due to the embedded growth structures at the nanometer scale, which are too small to be probed. Through a 3D rotational electron diffraction method combined with high resolution transmission electron microscopy, we have successfully determined the specific phase of each FexGe island on the Ge substrate. Three major phases (two hexagonal and one monoclinic) were found existing in the FexGe islands with nearly equal probability and independent of the deposition temperatures and time. All the islands with different phases were inclined to {111}Ge planes, which was due to a comparatively higher energy barrier for Fe atom diffusion through {111}Ge than other Ge planes. The epitaxial growth relationship at the interface was as follows: FeGemono(4−2−1)//Ge(111), FeGemono[15−6]//Ge[1−10], Fe3Ge2(201)//Ge(111) and Fe3Ge2[−112]//Ge[1−10], Fe13Ge8(40−1)//Ge(111) and Fe13Ge8[124]//Ge[1−10]. Ferromagnetism for the as-deposited samples was observed via SQUID, which most probably is attributed to the hexagonal FeGe phases. [ABSTRACT FROM AUTHOR]

Blood tests are considered as standard clinical procedures to screen for markers of diseases and health conditions. However, the complex cellular background (>99.9% RBCs) and biomolecular composition often pose significant technical challenges for accurate blood analysis. An emerging approach for point-of-care blood diagnostics is utilizing "label-free" microfluidic technologies that rely on intrinsic cell properties for blood fractionation and disease detection without any antibody binding. A growing body of clinical evidence has also reported that cellular dysfunction and their biophysical phenotypes are complementary to standard hematoanalyzer analysis (complete blood count) and can provide a more comprehensive health profiling. In this review, we will summarize recent advances in microfluidic label-free separation of different blood cell components including circulating tumor cells, leukocytes, platelets and nanoscale extracellular vesicles. Label-free single cell analysis of intrinsic cell morphology, spectrochemical properties, dielectric parameters and biophysical characteristics as novel blood-based biomarkers will also be presented. Next, we will highlight research efforts that combine label-free microfluidics with machine learning approaches to enhance detection sensitivity and specificity in clinical studies, as well as innovative microfluidic solutions which are capable of fully integrated and label-free blood cell sorting and analysis. Lastly, we will envisage the current challenges and future outlook of label-free microfluidics platforms for high throughput multi-dimensional blood cell analysis to identify non-traditional circulating biomarkers for clinical diagnostics. [ABSTRACT FROM AUTHOR]

A new germanosilicate zeolite (denoted as ITQ-53) with extra-large pores has been synthesised using tri-tertbutylmethylphosphonium cation as the organic structure directing agent (OSDA). Rotation electron diffraction (RED) was used to identify ITQ-53 from an initially-synthesised sample containing impurities, and to solve its structure. The structure was refined against PXRD data of pure ITQ-53 samples obtained after synthesis optimisation. ITQ-53 is the first example of extra-large pore zeolites with tri-directional interconnected 14 × 14 × 14-ring channels. It is stable up to at least 650 °C. The structure of ITQ-53 changes from monoclinic to orthorhombic upon calcination. [ABSTRACT FROM AUTHOR]

Bismuth subgallate has been used in wound and gastrointestinal therapy for over a century. The combination of continuous rotation electron diffraction and sample cooling finally revealed its structure as a coordination polymer. The structure provides insight regarding its formula, poor solubility, acid resistance and previously unreported gas sorption properties. [ABSTRACT FROM AUTHOR]

Folding–unfolding imparts fluorescence dual color switching, thus a novel concept to switch fluorescence between two distinct colors while avoiding traditional bond rupturing and bond forming in photoswitching. Because folding and unfolding minimize the wear and tear on molecular structures, the new systems have excellent reversibility and fatigue resistance. [ABSTRACT FROM AUTHOR]

Graphene aerogel (GA)-supported metal–organic framework (MOF) particles with a three-dimensional (3D) architecture were fabricated for the first time via a facile template-free “sol-cryo” method. The prepared MOFs@graphene hybrid aerogels exhibit a 3D interconnected macroporous framework of graphene sheets with uniform dispersion of MOF particles. We also report the first attempt at using the hybrid aerogels as adsorbents for the solid-phase extraction (SPE) of non-steroidal anti-inflammatory drugs (NSAIDs) and the selective enrichment of proteins. The macroporous skeletons of GA provide both low backpressure and rapid mass transfer in SPE application, thus overcoming the obstacle of high backpressure caused by directly packing submicron or micron sized MOF particles into SPE cartridges. Excellent performances including satisfactory recoveries, high sensitivity and good reproducibility were achieved in the extraction of five NSAIDs. The hybrid aerogels also showed an interesting ability for selective enrichment of ribonuclease A (RNase A) and simultaneous exclusion of cytochrome C (Cyt C) and lysozyme (Lyz), which could be attributed to the electrostatic interactions between proteins and the positively charged coordinatively unsaturated metal sites (CUS) in MIL-101. We believe that this work will promote the application of MOFs in adsorption and separation, and our synthetic strategy could be further extended to develop other graphene-based hybrid aerogels. [ABSTRACT FROM AUTHOR]