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Janus particles have been considered suitable for biomedicine owing to their asymmetric structure and unique properties. Although Janus particles have been applied in biosensing for dual-mode sensing, there are almost no reports for the detection of multiple indicators. In fact, many patients require different diagnoses, such as the examination of hepatogenic diseases in diabetics. Here, a Janus particle based on SiO2 was synthesized using a Pickering emulsion method. A novel strategy for detecting glucose and alpha-fetoprotein (AFP) based on different principles using this Janus particle was then constructed as a detection platform. Composed of adjustable dendritic silica loaded with gold nanoclusters (Au NCs) and glucose oxidase (GOx) and spherical SiO2 coupled with AFP antibody, this Janus fluorescent probe achieved the double detection of glucose and AFP. With the protection of dendritic silica, the enzyme temperature stability was enhanced. Moreover, the low limit of detection for glucose (0.5 μM in PBS and 2.5 μM in serum) and AFP (0.5 ng mL−1) illustrated the feasibility of the application of the Janus material in integrated detection. This work not only supported the use of a Janus fluorescent probe as a detection platform toward glucose and AFP but also showed the potential of Janus particles in integrated detection in the future. [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]

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]

Antibody-gated indicator delivery (gAID) systems based on mesoporous silica nano- and microparticle scaffolds are a promising class of materials for the sensitive chemical detection of small-molecule analytes in simple test formats such as lateral flow assays (LFAs) or microfluidic chips. Their architecture is reminiscent of drug delivery systems, only that reporter molecules instead of drugs are stored in the voids of a porous host particle. In addition, the pores are closed with macromolecular "caps" through a tailored "gatekeeping" recognition chemistry so that the caps are opened when an analyte has reacted with a "gatekeeper". The subsequent uncapping leads to a release of a large number of indicator molecules, endowing the system with signal amplification features. Particular benefits of such systems are their modularity and adaptability. With the example of the immunochemical detection of type-I pyrethroids by fluorescent dye-releasing gAID systems, the influence of several tuning modes on the optimisation of such hybrid sensory materials is introduced here. In particular, different mesoporous silica supports (from nano- and microparticles to platelets and short fibres), different functionalisation routes and different loading sequences were assessed. The materials' performances were evaluated by studying their temporal response behaviour and detection sensitivity, including the tightness of pore closure (through the amount of blank release in the absence of analyte) and the release kinetics. Our results indicate that the better the paratope-accommodating Fab region of the antibody "cap" fits into the host material's pore opening, the better the closing/opening mechanism can be controlled. Because such materials are well-suited for LFAs, performance assessment included a test-strip format besides conventional assays in suspension. In combination with dyes as indicators and smartphones for read-out, simple analytical tests for use by untrained personnel directly at a point-of-need such as an aeroplane cabin can be devised, allowing for sensitivities down to the μg kg−1 range in <5 min with case-required selectivities. [ABSTRACT FROM AUTHOR]

Recently, topical Mn4+-activated fluoride red phosphors with unique narrow band emission and excellent luminous performance have been widely reported for application in white light-emitting diodes (WLEDs). However, the weak moisture-resistance of these composites is a significant challenge. Here, we report a zeolite-encapsulating Cs2SiF6:Mn4+ (CSFM-Y) composite with significantly improved moisture resistance, which is synthesized by a facile method of ion exchange and in situ precipitation inside the pores of the zeolite at room temperature. This method takes full advantage of the porous structure of the zeolite and the cation-exchangeable features within the pores. The 3D interconnecting pores of the zeolite allow CsSiF6:Mn2+ (CSFM) to be well dispersed beneath the surface of the zeolite to give the emission, and the reduced size of the pores, owing to being partially occupied by CSFM crystals, provides an obstacle to further attack from water molecules. The stability test revealed that the luminous efficiency of WLEDs containing CSFM-Y reduces by only 4% after a duration of 120 h under high humidity (85%) and high temperature (85 °C) testing conditions, in comparison the luminous efficiency of the WLEDs fabricated using pure CSFM declines by 28%. This research reports a facile in situ synthesis approach for a CSFM-Y composite, which is promising for application in WLEDs. [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]

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]

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]

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]

The zinc–air battery is a promising energy device because of its high energy density and high safety. Developing efficient electrocatalysts for the oxygen reduction reaction (ORR) in air electrode is of great importance for high-performance zinc–air batteries. Herein, we first report N, P and Fe-tridoped nanoporous carbon ORR electrocatalysts derived from plant biomass corn silk. It is a cheap, accessible and recyclable biomass, which can offer a good basis for developing catalysts with low-cost and high yield production. The electrocatalysts were prepared by a hydrothermal process and a two step heat treatment process. The Fe element doped in the catalyst mainly came from FeCl3 and the P element came from corn silks. The N was from NH3 and corn silks. The biomass-derived catalyst exhibited a remarkably higher ORR activity, superior stability and tolerance to methanol poisoning effects in alkaline media than Pt/C catalyst. The catalyst also showed higher voltage and higher specific capacity than the Pt/C in a zinc–air battery and it may be an alternative to Pt/C in the practical application of the zinc–air battery. This study showed the possibility for rational design and preparation of high-performance electrocatalysts with a low-cost from a highly available and recyclable plant biomass. [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]

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 electrochemical reduction (ECR) of CO 2 is a powerful strategy to reduce the world's carbon footprint by converting CO 2 to useful products such as CH 3 OH and CO. Recent techno-economic analysis has found that for the electro-conversion of CO 2 to be adapted for practical use, the main products formed from this reaction need to be low-order, such as CO. This review summarizes recent progress in the ECR of CO 2 to CO on nano-electrocatalysts (noble, non-noble metals and carbon nanomaterials) and provides the limitations and challenges that each electrocatalyst faces. It discusses the mechanism behind the performance of the electrocatalysts and offers the potential future prospects of the ECR process., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

Photoswitching of bis(dithiazole)ethene can be regulated by Hg(II) ions and EDTA in a "lock-and-unlock" manner. The molecular photoswitch provides an enzyme-like binding pocket that selectively binds specifically to mercury ions, thus modulating the degree of photoswitching in its presence.