Photochemical and biological dual-effects enhance the inhibition of photosensitizers for tumour growth

Photosensitizers typically rely on a singular photochemical reaction to generate reactive oxygen species, which can then inhibit or eradicate lesions. However, photosensitizers often exhibit limited therapeutic efficiency due to their reliance on a single photochemical effect. Herein, we propose a new strategy that integrates the photochemical effect (type-I photochemical effect) with a biological effect (proton sponge effect). To test our strategy, we designed a series of photosensitizers (ZZ-sers) based on the naphthalimide molecule. ZZ-sers incorporate both a p-toluenesulfonyl moiety and weakly basic groups to activate the proton sponge effect while simultaneously strengthening the type-I photochemical effect, resulting in enhanced apoptosis and programmed cell death. Experiments confirmed near-complete eradication of the tumour burden after 14 days (Wlight/Wcontrol ≈ 0.18, W represents the tumour weight). These findings support the notion that the coupling of a type-I photochemical effect with a proton sponge effect can enhance the tumour inhibition by ZZ-sers, even if the basic molecular backbones of the photosensitizers exhibit nearly zero or minimal tumour inhibition ability. We anticipate that this strategy can be generalized to develop additional new photosensitizers with improved therapeutic efficacy while overcoming limitations associated with systems relying solely on single photochemical effects.

Enantioselective copper-catalyzed B-H bond insertion reaction of α-diazo phosphonates to access chiral α-boryl phosphonates

Chiral phosphorus-containing compounds find applications across various fields, including asymmetric catalysis, medicinal chemistry, and materials science. Despite the abundance of reported highly enantioselective methods for synthesizing various chiral phosphorus compounds, the enantioselective synthesis of α-boryl phosphorus compounds still remains an unknown territory. Here, we report a method for the construction of chiral α-boryl phosphates by asymmetric B-H insertion reaction using α-diazo phosphates as carbene precursors, cheap and readily available copper salt as the catalyst and chiral oxazoline as the ligand. This method can directly afford a series of stable α-boryl phosphates with a yield up to 97% and an enantioselectivity up to 98% ee. The operating procedure of this method is straightforward, offering a broad substrate applicability, remarkable tolerance towards various functional groups, and gentle reaction conditions.

Iodoarene-directed photoredox β-C(sp3)-H arylation of 1-(o-iodoaryl)alkan-1-ones with cyanoarenes via halogen atom transfer and hydrogen atom transfer

Site selective functionalization of inert remote C(sp3)-H bonds to increase molecular complexity offers vital potential for chemical synthesis and new drug development, thus it has been attracting ongoing research interest. In particular, typical β-C(sp3)-H arylation methods using chelation-assisted metal catalysis or metal-catalyzed oxidative/photochemical in situ generated allyl C(sp3)-H bond processes have been well developed. However, radical-mediated direct β-C(sp3)-H arylation of carbonyls remains elusive. Herein, we describe an iodoarene-directed photoredox β-C(sp3)-H arylation of 1-(o-iodoaryl)alkan-1-ones with cyanoarenes via halogen atom transfer (XAT) and hydrogen atom transfer (HAT). The method involves diethylaminoethyl radical-mediated generation of an aryl radical intermediate via XAT, then directed 1,5-HAT to form the remote alkyl radical intermediate and radical-radical coupling with cyanoarenes, and is applicable to a broad scope of unactivated remote C(sp3)-H bonds like β-C(sp3)-H bonds of o-iodoaryl-substituted alkanones and α-C(sp3)-H bonds of o-iodoarylamides. Experimental findings are supported by computational studies (DFT calculations), revealing that this method operates via a radical-relay stepwise mechanism involving multiple SET, XAT, 1,5-HAT and radical-radical coupling processes.

Near-infrared imaging for visualizing the synergistic relationship between autophagy and NFS1 protein during multidrug resistance using an ICT-TICT integrated platform

Drug resistance is a major challenge for cancer treatment, and its identification is crucial for medical research. However, since drug resistance is a multi-faceted phenomenon, it is important to simultaneously evaluate multiple target fluctuations. Recently developed fluorescence-based probes that can simultaneously respond to multiple targets offer many advantages for real-time and in situ monitoring of cellular metabolism, including ease of operation, rapid reporting, and their non-invasive nature. As such we developed a dual-response platform (Vis-H2S) with integrated ICT-TICT to image H2S and viscosity in mitochondria, which could simultaneously track fluctuations in cysteine desulfurase (NFS1 protein and H2S inducer) and autophagy during chemotherapy-induced multidrug resistance. This platform could monitor multiple endogenous metabolites and the synergistic relationship between autophagy and NFS1 protein during multidrug resistance induced by chemotherapy. The results indicated that chemotherapeutic drugs simultaneously up-regulate the levels of NFS1 protein and autophagy. It was also found that the NFS1 protein was linked with autophagy, which eventually led to multidrug resistance. As such, this platform could serve as an effective tool for the in-depth exploration of drug resistance mechanisms.

Corals-inspired magnetic absorbents for fast and efficient removal of microplastics in various water sources

Microplastics (MPs) as the formidable pollutants with high toxicity and difficult degradation may threaten the aquaculture industry and human health, making it highly necessary to develop the effective removal methods. In this article, Fe3O4 nanoparticles (NPs) were initially fabricated with mesoporous structure, but showing undesirable adsorption efficiencies for the adsorption of MPs (lower than 70%). Inspired by the reefs-rebuilding corals acting as the sinks for various marine pollutants like plastic, Fe3O4 NPs were coated further with adhesive polymerized dopamine (PDA) yielding Fe3O4@PDA absorbents. Unexpectedly, it was discovered that the corals-mimicking absorbents so formed could allow for the removal of MPs with dramatically enhanced efficiencies up to 98.5%, which is over about 30% higher than those of bare Fe3O4 NPs. Herein, the PDA shells might conduct the increased adhesion to MPs, presumably through the formation of hydrogen bonding, π-π stacking, and hydrophobic interactions. A fast (within 20 min) and stable adsorption of MPs can also be expected, in addition to the PDA-improved environmental storage of Fe3O4 NPs. Subsequently, the Fe3O4@PDA adsorbents were utilized to remove MPs from different water sources with high efficiencies, including pure water, suburban streams, village rivers, lake water, inner-city moats, and aquaculture water. Such a magnet-recyclable adsorbent may provide a new way for rapid, effective, and low-cost removal of MPs pollutants from various water systems.

De Novo Green Fluorescent Protein Chromophore-Based Probes for Capturing Latent Fingerprints Using a Portable System

Rapid visualization of latent fingerprints, preferably at their point of origin, is essential for effective crime scene evaluation. Here, we present a new class of green fluorescent protein chromophore-based fluorescent dyes (LFP-Yellow and LFP-Red) that can be used for real-time visualization of LFPs within 10 s. Compared with traditional chemical reagents for LFPs, these fluorescent dyes are completely water-soluble, exhibit low cytotoxicity, and are harmless to users. Level 1-3 details of the LFPs could be clearly revealed through "off-on" fluorescence signal readout. Additionally, the fluorescent dyes were constructed based on an imidazolinone core and so do not contain pyridine groups or metal ions, which ensures that the DNA is not contaminated during extraction and identification after the LFPs are treated with the dyes. Combined with our as-developed portable system for capturing LFPs, LFP-Yellow and LFP-Red enabled the rapid capture of LFPs. Therefore, these green fluorescent protein chromophore-based probes provide an approach for the rapid identification of individuals who were present at a crime scene.

Self-assembled dendrimer polyamide nanofilms with enhanced effective pore area for ion separation

Membrane technology using well-defined pore structure can achieve high ion purity and recovery. However, fine-tuning the inner pore structure of the separation nanofilm to be uniform and enhance the effective pore area is still challenging. Here, we report dendrimers with different peripheral groups that preferentially self-assemble in aqueous-phase amine solution to facilitate the formation of polyamide nanofilms with a well-defined effective pore range and uniform pore structure. The high permeabilities are maintained by forming asymmetric hollow nanostripe nanofilms, and their well-designed ion effective separation pore ranges show an enhancement, rationalized by molecular simulation. The self-assembled dendrimer polyamide membrane provides Cl-/SO42- selectivity more than 17 times that of its pristine polyamide counterparts, increasing from 167.9 to 2883.0. Furthermore, the designed membranes achieve higher Li purity and Li recovery compared to current state-of-the-art membranes. Such an approach provides a scalable strategy to fine-tune subnanometre structures in ion separation nanofilms.

Spontaneous Formation of Ultrasmall Noble Metal Nanoparticles on Cobalt-Based Layered Double Hydroxide for Electrochemical and Environmental Catalysis

Supported noble metal nanoparticles (NMNPs) are appealing for energy and environment catalysis. To facilitate the loading of NMNPs, in situ reduction of Mn+ on the support with extra reductants/surfactants is adopted, but typically results in aggregated NMNPs with uneven size distributions or blocked active sites of the NMNPs. Herein, the use of cobalt layered double hydroxide (Co-LDH) is proposed as both support and reductant for the preparation of supported NMNPs with ultrasmall sizes and even distributions. The resultant Co-LDH-supported NMNPs exhibit excellent catalytic performance and stability. For example, Ir/Co-LDH displays a low overpotential of 188 mV (10 mA cm-2 ) for electrocatalytic oxygen evolution reaction and a long-term stability over 100 h (100 mA cm-2 ) in overall water splitting. Ru/Co-LDH can achieve a 4-nitrophenol reduction with high rate of 0.36 min-1 and S2- detection with low limit of detection (LOD) of 0.34 µm. Overall, this work provides a green and effective strategy to fabricate supported NMNPs with greatly improved catalytic performances.

Selective FRET nano probe based on carbon dots and naphthalimide-isatin for the ratiometric detection of peroxynitrite in drug-induced liver injury

Drug-induced liver injury (DILI) is the most common cause for acute liver failure in the USA and Europe. However, most of DILI cases can recover or be prevented if treatment by the offending drug is discontinued. Recent research indicates that peroxynitrite (ONOO-) can be a potential indicator to diagnose DILI at an early stage. Therefore, the establishment of an assay to detect and track ONOO- in DILI cases is urgently needed. Here, a FRET-based ratiometric nano fluorescent probe CD-N-I was developed to detect ONOO- with high selectivity and excellent sensitivity. This probe consists of carbon dots and a naphthalimide-isatin peroxynitrite sensing system assembled based on electrostatic interactions. Using CD-N-I we were able to detect exogenous ONOO- in live cells and endogenous ONOO- in APAP-induced liver injury of HepG2 cells.

BINOL as a Chiral Solvating Agent for Sulfiniminoboronic Acids

1H NMR spectroscopic studies using BINOL as a chiral solvating agent (CSA) for a scalemic sulfiniminoboronic acid (SIBA) have revealed concentration- and enantiopurity-dependent variations in the chemical shifts of diagnostic imine protons used to determine enantiopurity levels. 11B/15N NMR spectroscopic studies and X-ray structural investigations revealed that unlike other iminoboronate species, BINOL-SIBA assemblies do not contain N-B coordination bonds, with 1H NMR NOESY experiments indicating that intermolecular H-bonding networks between BINOL and the SIBA analyte are responsible for these variations. These effects can lead to diastereomeric signal overlap at certain er values that could potentially lead to enantiopurity/configuration misassignments. Consequently, it is recommended that hydrogen-bonding-CSA-based 1H NMR protocols should be repeated using both CSA enantiomers to ensure that any concentration- and/or er-dependent variations in diagnostic chemical shifts are accounted for when determining the enantiopurity of a scalemic analyte.

Engineering a molecular ruthenium catalyst into three-dimensional metal covalent organic frameworks for efficient water oxidation

The water oxidation reaction plays an important role in clean energy conversion, utilization, and storage, but mimicking the oxygen-evolving complex of photosystem II for designing active and stable water oxidation catalysts (WOCs) is still an appealing challenge. Here, we innovatively engineered a molecular ruthenium WOC as a metal complex building unit to construct a series of three-dimensional metal covalent organic frameworks (3D MCOFs) for realizing efficient oxidation catalysis. The resultant MCOFs possessed rare 3D interlocking structures with inclined interpenetration of two-dimensional covalent rhombic nets, and the Ru sites were periodically arranged in the crystalline porous frameworks. Impressively, these MCOFs showed excellent performance towards water oxidation (the O2 evolution rate is as high as 2830 nmol g-1 s-1) via the water nucleophilic attack pathway. Besides, the MCOFs were also reactive for oxidizing organic substrates. This work highlights the potential of MCOFs as a designable platform in integrating molecular catalysts for various applications.

Unveiling the Crucial Roles of O2•- and ATP in Hepatic Ischemia-Reperfusion Injury Using Dual-Color/Reversible Fluorescence Imaging

Hepatic ischemia-reperfusion injury (HIRI) is mainly responsible for morbidity or death due to graft rejection after liver transplantation. During HIRI, superoxide anion (O2•-) and adenosine-5'-triphosphate (ATP) have been identified as pivotal biomarkers associated with oxidative stress and energy metabolism, respectively. However, how the temporal and spatial fluctuations of O2•- and ATP coordinate changes in HIRI and particularly how they synergistically regulate each other in the pathological mechanism of HIRI remains unclear. Herein, we rationally designed and successfully synthesized a dual-color and dual-reversible molecular fluorescent probe (UDP) for dynamic and simultaneous visualization of O2•- and ATP in real-time, and uncovered their interrelationship and synergy in HIRI. UDP featured excellent sensitivity, selectivity, and reversibility in response to O2•- and ATP, which rendered UDP suitable for detecting O2•- and ATP and generating independent responses in the blue and red fluorescence channels without spectral crosstalk. Notably, in situ imaging with UDP revealed for the first time synchronous O2•- bursts and ATP depletion in hepatocytes and mouse livers during the process of HIRI. Surprisingly, a slight increase in ATP was observed during reperfusion. More importantly, intracellular O2•-─succinate dehydrogenase (SDH)─mitochondrial (Mito) reduced nicotinamide adenine dinucleotide (NADH)─Mito ATP─intracellular ATP cascade signaling pathway in the HIRI process was unveiled which illustrated the correlation between O2•- and ATP for the first time. This research confirms the potential of UDP for the dynamic monitoring of HIRI and provides a clear illustration of HIRI pathogenesis.

Near-Infrared Fluorescent Probe for the In Situ Visualization of Oxidative Stress in the Brains of Neuroinflammatory and Schizophrenic Mice

Schizophrenia is a common mental disorder with unclear mechanisms. Oxidative stress and neuroinflammation play important roles in the pathological process of schizophrenia. Superoxide anion (O2•-) is an important oxidative stress biomarker in vivo. However, due to the existence of the blood-brain barrier (BBB), few near-infrared (NIR) fluorescent probes have been used for the sensing and detection of O2•- in the brain. With this research, we developed the first near-infrared fluorescent probe (named CT-CF3) for noninvasive detection of endogenous O2•- in the brain of mice. Enabling fluorescence monitoring of the dynamic changes in O2•- flux due to the prolonged activation of microglia in neuroinflamed and schizophrenic (SZ) mice brains, thereby providing direct evidence for the relationship between oxidative stress, neuroinflammation, and schizophrenia. Furthermore, we confirmed the O2•- burst in the brains of first-episode schizophrenic mice and assessed the effect of two atypical antipsychotic drugs (risperidone and olanzapine) on redox homeostasis.

Metal-organic framework (MOF) hybridized gold nanoparticles as a bifunctional nanozyme for glucose sensing

Inspired by natural enzymes that possess multiple catalytic activities, here we develop a bifunctional metal-organic frame-work (MOF) for biosensing applications. Ultrasmall gold nano-particles (AuNPs) are grown in the internal cavities of an iron (Fe) porphyrin-based MOF to produce a hybridized nanozyme, AuNPs@PCN-224(Fe), in which AuNPs and PCN-224(Fe) exhibit the catalytic activity of glucose oxidase (GOx) and horseradish peroxidase (HRP), respectively. We established that the bifunctional nanozyme was capable of a cascade reaction to generate hydrogen peroxide in the presence of d-glucose and oxygen in situ, and subsequently activate a colorimetric or chemiluminescent substrate through HRP-mimicking catalytic activity. The nanozyme was selective over a range of other saccharides, and 93% of the catalytic activity was retained after being recycled five times.

Synthesis and Characterization of Ferric Vanadate Nanorods for Efficient Electrochemical Detection of Ascorbic Acid

This study reports the synthesis of ferric vanadate (FeVO₄) via a facile hydrothermal method, focusing on demonstrating its exceptional electrochemical (EC) properties on detecting low-density ascorbic acid (AA). The phase purity, crystallinity, structure, morphology, and chemical compositional properties were characterized by employing X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy techniques. EC impedance spectroscopy and cyclic voltammetry techniques were also adopted in order to assess the EC response of a FeVO₄-modified glassy carbon electrode for sensing AA at room temperature. The AA concentration range adopted in this experiment is 0.1-0.3 mM at a working electric potential of -0.13 V. The result showed functional excellence of this material for the EC determination of AA with good stability and reproducibility, promising its potentiality in connection with relevant sensing applications.

Photoactivatable senolysis with single-cell resolution delays aging

Strategies that can selectively eliminate senescent cells (SnCs), namely senolytics, have been shown to promote healthy lifespan. However, it is challenging to achieve precise, broad-spectrum and tractable senolysis. Here, we integrate multiple technologies that combine the enzyme substrate of senescence-associated β-galactosidase (SA-β-gal) with fluorescence tag for the precise tracking of SnCs, construction of a bioorthogonal receptor triggered by SA-β-gal to target and anchor SnCs with single-cell resolution and incorporation of a selenium atom to generate singlet oxygen and achieve precise senolysis through controllable photodynamic therapy (PDT). We generate KSL0608-Se, a photosensitive senolytic prodrug, which is selectively activated by SA-β-gal. In naturally-aged mice, KSL0608-Se-mediated PDT prevented upregulation of age-related SnCs markers and senescence-associated secretory phenotype factors. This treatment also countered age-induced losses in liver and renal function and inhibited the age-associated physical dysfunction in mice. We therefore provide a strategy to monitor and selectively eliminate SnCs to regulate aging.

Two-dimensional wide-bandgap GeSe2 vertical ultraviolet photodetectors with high responsivity and ultrafast response speed

Germanium selenide (GeSe₂), as a typical member of 2D wide bandgap semiconductors (WBSs), shows great potential in ultraviolet (UV) optoelectronics due to its excellent flexibility, superior environmental stability, competitive UV absorption coefficient, and significant spectral selectivity. However, the GeSe₂-based UV photodetector suffers from high operation voltages and low photocurrent, which prevents its practical imaging applications. In this work, we report an elevated photocurrent generation in a vertical stacking graphene/GeSe₂/graphene heterostructure with low operation voltage and low power consumption. Efficient collection of photoexcited carriers in GeSe₂ through graphene electrodes results in outstanding UV detection properties, including a pronounced responsivity of 37.1 A W^-1, a specific detectivity of 8.83 × 10¹¹ Jones, and an ultrahigh on/off ratio (∼10⁵) at 355 nm. In addition, building a Schottky barrier between GeSe₂ and graphene and reducing the channel length can increase the photoresponse speed to ∼300 μs. These accomplishments set the stage for future optoelectronic applications of vertical 2D WBS heterostructure UV photodetectors.

Alkoxysulfonyl radical species: acquisition and transformation towards sulfonate esters through electrochemistry

Sulfonyl radical mediated processes have been considered as a powerful strategy for the construction of sulfonyl compounds. However, an efficient and high atom-economical radical approach to the synthesis of sulfonate esters is still rare, owing to the limited tactics to achieve alkoxysulfonyl radicals. Herein, an electrochemical anodic oxidation of inorganic sulfites with alcohols is developed to afford alkoxysulfonyl radical species, which are utilized in subsequent alkene difunctionalization to provide various sulfonate esters. This transformation features excellent chemoselectivity and broad functional group tolerance. This new discovery presents the potential prospect for the construction of sulfonate esters, and enriches the electrochemical reaction type.

Imaging of hypochlorous acid in mitochondria using an asymmetric near-infrared fluorescent probe with large Stokes shift

Small-molecule near-infrared (NIR) imaging facilitates deep tissue penetration, low autofluorescence, non-invasive visualization, and a relatively simple operation. As such it has emerged as a popular technique for tracking biological species and events. However, the small Stokes shift of most NIR dyes often results in a low signal-to-noise ratio and self-quenching due to crosstalk between the excitation and emission spectra. With this research, we developed a NIR-based fluorescent probe WD-HOCl for hypochlorous acid (HOCl) detection using the NIR dye TJ730 as the fluorophore, which exhibits a large Stokes shift of 156 nm, with no crosstalk between the excitation and emission spectra. It contains acyl hydrazide as the responsive group and a pyridinium cation as the mitochondria-targeting group. The fluorescence intensity of WD-HOCl was enhanced by 30.1-fold after reacting with HOCl. Imaging studies performed using BV-2 cells indicated that WD-HOCl could be used for endogenous HOCl detection and imaging in living cells exposed to glucose and oxygen deprivation/reperfusion. Finally, we demonstrated that inhibiting the expression of NOX2 reduced the HOCl levels and the severity of oxidative stress during stroke in a mouse model.

Enantioselective Copper-Catalyzed sp2/sp3 Diborylation of 1-Chloro-1-Trifluoromethylalkenes

Fluorine-containing organoboron compounds have emerged as novel building blocks in chemical synthesis; among them, fluorinated sp²/sp³ diborylated compounds are particularly appealing, since they might undergo chemoselective and diversified transformations of different C-B bonds with fluorinated functionality, thus bringing versatility and complexity to the eventual products. However, expedient, synthetic strategies for the construction of such fluorinated diborylative compounds are very sparse. Herein, we disclose enantioselective Cu-catalyzed sp²/sp³ diborylations of 1-chloro-1-trifluoromethylalkenes, leading to diborylated compounds bearing a gem-difluoroalkenyl moiety; most intriguingly, the new formed C-B bonds include one stereoselective and optically pure Csp³-B bond. Further transformations on the eventual products demonstrated the values of our presented strategy.

Effects of 5-azaC on Iridoid Glycoside Accumulation and DNA Methylation in Rehmannia glutinosa

Iridoid glycoside is the important secondary metabolite and the main active component in Rehmannia glutinosa. However, the mechanisms that underlie the regulation of iridoid glycoside biosynthesis remain poorly understood in R. glutinosa. Herein, the analysis of RNA-seq data revealed that 3,394 unigenes related to the biosynthesis of secondary metabolites were identified in R. glutinosa. A total of 357 unigenes were involved in iridoid glycoside synthesis, in which the highly conservative genes, such as DXS, DXR, GPPS, G10H, and 10HGO, in organisms were overexpressed. The analysis of the above genes confirmed that the co-occurrence ratio of DXS, DXR, and GPPS was high in plants. Further, our results showed that under normal and 5-azacytidine (5-azaC) treatment, the expression levels of DXS, DXR, GPPS, G10H, and 10HGO were consistent with the iridoid glycoside accumulation in R. glutinosa, in which the application of the different concentrations of 5-azaC, especially 50 μM 5-azaC, could significantly upregulate the expression of five genes above and iridoid glycoside content. In addition, the changes in the spatiotemporal specificity of degree and levels of DNA methylation were observed in R. glutinosa, in which the hemi-methylation was the main reason for the change in DNA methylation levels. Similar to the changes in 5-methyl cytosine (5mC) content, the DNA demethylation could be induced by 5-azaC and responded in a dose-dependent manner to 15, 50, and 100 μM 5-azaC. Taken together, the expression of iridoid glycoside synthesis gene was upregulated by the demethylation in R. glutinosa, followed by triggering the iridoid glycoside accumulation. These findings not only identify the key genes of iridoid glycoside synthesis from R. glutinosa, but also expand our current knowledge of the function of methylation in iridoid glycoside accumulation.

Semi-Planar Non-Fullerene Molecules Enhance the Durability of Flexible Perovskite Solar Cells

Flexible perovskite solar cells (FPSCs) represent a promising technology in the development of next-generation photovoltaic and optoelectronic devices. SnO2 electron transport layers (ETL) typically undergo significant cracking during the bending process of FPSCs, which can significantly compromise their charge transport properties. Herein, the semi-planar non-fullerene acceptor molecule Y6 (BT-core-based fused-unit dithienothiophen [3,2-b]-pyrrolobenzothiadiazole derivative) is introduced as the buffer layer for SnO2 -based FPSCs. It is found that the Y6 buffer layer can enhance the ability of charge extraction and bending stability for SnO2 ETL. Moreover, the internal stress of perovskite films is also reduced. As a result, SnO2 /Y6-based FPSCs achieved a power conversion efficiency (PCE) of 20.09% and retained over 80% of their initial efficiency after 1000 bending cycles at a curvature radius of 8 mm, while SnO2 -based devices only retain 60% of their initial PCE (18.60%) upon the same bending cycles. In addition, the interfacial charge extraction is also effectively improved in conjunction with reduced defect density upon incorporation of Y6 on the SnO2 ETL, as revealed by femtosecond transient absorption (Fs-TA) measurements.

Transient Chelating Group-Controlled Stereoselective Rh(I)-Catalyzed Silylative Aminocarbonylation of 2-Alkynylanilines: Entry to (Z)-3-(Silylmethylene)indolin-2-ones

A new, mild acryl transient chelating group-controlled stereoselective Rh(I)-catalyzed silylative aminocarbonylation of 2-alkynylanilines with CO and silanes for producing (Z)-3-(silylmethylene)indolin-2-ones is presented. By using an acryl transient chelating group 2-alkynylanilines...

Graphene nanoribbon-based supramolecular ensembles with dual-receptor targeting function for targeted photothermal tumor therapy

Triple negative breast cancer (TNBC) is one of the most malignant subtypes of breast cancer. Here, we report the construction of graphene nanoribbon (GNR)-based supramolecular ensembles with dual-receptor (mannose and αvβ3 integrin receptors) targeting function, denoted as GNR-Man/PRGD, for targeted photothermal treatment (PTT) of TNBC. The GNR-Man/PRGD ensembles were constructed through the solution-based self-assembly of mannose-grafted GNRs (GNR-Man) with a pyrene-tagged αvβ3 integrin ligand (PRGD). Enhanced PTT efficacies were achieved both in vitro and in vivo compared to that of the non-targeting equivalents. Tumor-bearing live mice were administered (tail vein) with GNR-Man/PRGD and then each mice group was subjected to PTT. Remarkably, GNR-Man/PRGD induced complete ablation of the solid tumors, and no tumor regrowth was observed over a period of 15 days. This study demonstrates a new and promising platform for the development of photothermal nanomaterials for targeted tumor therapy.

High Proton-Conductivity in Covalently Linked Polyoxometalate-Organoboronic Acid-Polymers

The controlled bottom-up design of polymers with metal oxide backbones is a grand challenge in materials design, as it could give unique control over the resulting chemical properties. Herein, we report a 1D-organo-functionalized polyoxometalate polymer featuring a purely inorganic backbone. The polymer is self-assembled from two types of monomers, inorganic Wells-Dawson-type polyoxometalates, and aromatic organo-boronates. Their covalent linkage results in 1D polymer strands, which combine an inorganic oxide backbone (based on B-O and Nb-O linkages) with functional organic side-chains. The polymer shows high bulk proton conductivity of up to 1.59×10-1  S cm-1 at 90 °C and 98 % relative humidity. This synthetic approach could lead to a new class of organic-inorganic polymers where function can be designed by controlled tuning of the monomer units.

TCF-ALP: a fluorescent probe for the selective detection of Staphylococcus bacteria and application in "smart" wound dressings

Alkaline phosphatase (ALP) is an important enzyme-based biomarker present in several bacterial species; however, it is currently undervalued as a strategy to detect pathogenic bacteria. Here, we explore our ALP-responsive colorimetric and fluorescent probe (TCF-ALP) for such applications. TCF-ALP displayed a colorimetric and fluorescence response towards Staphylococcus aureus (S. aureus), with a limit of detection of 3.7 × 106 CFU mL-1 after 24 h incubation. To our surprise, TCF-ALP proved selective towards Staphylococcus bacteria when compared with Enterococcus faecalis (E. faecalis), and Gram-negative P. aeruginosa and E. coli. Selectivity was also seen in clinically relevant S. aureus biofilms. Owing to the high prevalence and surface location of S. aureus in chronic wounds, TCF-ALP was subsequently encapsulated in polyvinyl alcohol (PVA)-based hydrogels as a proof-of-concept "smart" wound dressing. TCF-ALP hydrogels were capable of detecting S. aureus in planktonic and biofilm assays, and displayed a clear colour change from yellow to purple after 24 h incubation using ex vivo porcine skin models. Overall, TCF-ALP is a simple tool that requires no prior knowledge, training, or specialist equipment, and has the potential to overcome issues related to invasive swabbing and tissue biopsy methods. Thus, TCF-ALP could be used as a tool to monitor the early development of infection in a wound and allow for the rapid provision of appropriate treatment for Staphylococcal bacterial infections.

Racemases and epimerases operating through a 1,1-proton transfer mechanism: reactivity, mechanism and inhibition

Racemases and epimerases catalyse changes in the stereochemical configurations of chiral centres and are of interest as model enzymes and as biotechnological tools. They also occupy pivotal positions within metabolic pathways and, hence, many of them are important drug targets. This review summarises the catalytic mechanisms of PLP-dependent, enolase family and cofactor-independent racemases and epimerases operating by a deprotonation/reprotonation (1,1-proton transfer) mechanism and methods for measuring their catalytic activity. Strategies for inhibiting these enzymes are reviewed, as are specific examples of inhibitors. Rational design of inhibitors based on substrates has been extensively explored but there is considerable scope for development of transition-state mimics and covalent inhibitors and for the identification of inhibitors by high-throughput, fragment and virtual screening approaches. The increasing availability of enzyme structures obtained using X-ray crystallography will facilitate development of inhibitors by rational design and fragment screening, whilst protein models will facilitate development of transition-state mimics.

Radical-based functionalization-oriented construction: rapid assembly of azaarene-substituted highly functionalized pyrroles

Totally different functionalization and construction as two fundamental synthetic protocols have long been applied to furnish azaarene variants. Here, a novel radical-based functionalization-oriented construction strategy by exploiting the electronic properties of azaarenes and the high reactivity of radicals is developed. Under a photoredox catalysis platform, the robust ability of such an artful combination of functionalization with construction is disclosed in the synthesis of valuable 3-azaarene-substituted densely functionalized pyrroles. In addition to the ability to use the readily accessible feedstocks, the high synthetic efficiency and the good functional group tolerance, the substrate scope is broad (81 examples) resulting from the capability to flexibly replace the types of azaarenes and other substituents. Control experiments and density functional theory (DFT) calculations elucidate the plausible mechanism involving the reaction pathways and the important role of NaH2PO4 as an additive in the reaction.

Synthesis and biological evaluation of fluorinated 3,4-dihydroquinolin-2(1H)-ones and 2-oxindoles for anti-hepatic fibrosis

(Z)-4-(Iodomethylene)-3-(2,2,2-trifluoroethyl)-3,4-dihydroquinolin-2(1H)-ones and fluorinated 3,3-disubstituted 2-oxindoles are synthesized and evaluated for anti-hepatic fibrosis. CCK-8 assay indicates that most of the compounds have no obvious cytotoxicity on the human hepatic stellate cells (HSC) cell line. Collagen I and fibrosin expression levels are tested by ELISA, and the results show that several compounds can inhibit the expression of collagen I and fibrosin. Additionally, results from real time-PCR reveal that only one compound can inhibit the expression level of α-SMA, suggesting that this compound can inhibit the activation of the HSC cell line. These studies demonstrate that this compound may be a potential novel drug candidate for anti-hepatic fibrosis (approximately 5-6 lines).

Fluorescent small organic probes for biosensing

Small-molecule based fluorescent probes are increasingly important for the detection and imaging of biological signaling molecules due to their simplicity, high selectivity and sensitivity, whilst being non-invasive, and suitable for real-time analysis of living systems. With this perspective we highlight sensing mechanisms including Förster resonance energy transfer (FRET), intramolecular charge transfer (ICT), photoinduced electron transfer (PeT), excited state intramolecular proton transfer (ESIPT), aggregation induced emission (AIE) and multiple modality fluorescence approaches including dual/triple sensing mechanisms (DSM or TSM). Throughout the perspective we highlight the remaining challenges and suggest potential directions for development towards improved small-molecule fluorescent probes suitable for biosensing.