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Organic photothermal materials can effectively convert solar energy into thermal energy in an environmentally friendly manner and have great potential for applications such as desalination and thermoelectric power generation. However, some organic photothermal materials have low photothermal conversion efficiency and a narrow range of solar absorption, limiting the improvement of photothermal performance. In this contribution, to achieve a lower energy gap and high photothermal conversion efficiency, a strong acceptor benzo[1,2-c:4,5-c′]bis([1,2,5]thiadiazole) (BBT) and the electron donor thiophene unit were introduced to synthesize a donor–acceptor (D–A) type organic conjugated molecule 4,8-bis(3-(2-ethylhexyl)-[2,2′-bithiophen]-5-yl)benzo[1,2-c:4,5-c′]bis([1,2,5]thiadiazole) (2TP-BBT). The atoms of C, N and S in BBT are essentially coplanar, attributed to the N atoms with higher electronegativity and C＝N groups with a lower-energy π-orbital, and benzothiadiazole exhibits strong electron-withdrawing properties. The 2TP-BBT solid shows a broad absorption spectrum ranging from 300 to 1400 nm. The 2TP-BBT solid has a high photothermal conversion efficiency of 22.38% under 1.0 kW m−2 simulated solar irradiation, and under laser irradiation at 980 nm, the solid photothermal conversion efficiency of the 2TP-BBT molecule reached 43.32%. Additionally, the 2TP-BBT/non-woven fabric is applied in solar-driven water evaporation with a water evaporation rate up to 1.35 kg m−2 h−1 under 1.0 kW m−2 simulated solar irradiation and a vapour conversion efficiency of 94.3%, which show superior water evaporation performance. The waste heat generated during solar water evaporation can be effectively used for synergistic thermoelectric power generation. This study demonstrates the application of photothermal D–A organic molecules in water purification and water–electric cogeneration application, therefore providing a valuable prospect of utilization in efficient solar thermal energy conversion. [ABSTRACT FROM AUTHOR]

Defects in metal oxides can significantly improve their physical and chemical properties. However, the conventional methods to generate defects often require complex procedures and harsh conditions. In this study, we design a simple and room-temperature preparation route to prepare defective metal oxide nanoparticles with high yield. The formation of defects is attributed to the generation of oxygen vacancies (VO) and hydrogenation caused by charge transfer at a Mg–metal oxide junction structure. Defective TiO2 exhibits excellent performance toward wastewater cleaning and water splitting. The proposed route is promising in terms of convenience, low cost, and large-scale production. [ABSTRACT FROM AUTHOR]

The melt polycondensation of glycolic acid based copolymers with high molecular weights remains a big challenge. In this work, poly(butylene furandicarboxylate-co-glycolate) (PBFGA) and poly(butylene furandicarboxylate)-b-poly(glycolic acid) (PBF-b-GA) copolyesters were synthesized via melt oligomer polycondensation and melt bulk transesterification, respectively. Herein, melt oligomer polycondensation is a better method with mild preparation conditions and products with higher molecular weights (Mw). The analysis of GPC demonstrated that PBFGAs possessed a Mw of up to 8.95 × 104 g mol−1. The PBFGAs also possessed excellent thermal stability (＞320 °C), which endowed the copolymers with a wider processing window than thermolabile PGA. DSC analyses displayed that PBFGA40–PBFGA10 were semi-crystalline materials that melted between 84.5 and 156 °C, while PBFGA50–60 were amorphous. Tensile tests indicated a high elastic modulus of 524–1262 MPa, tensile strength of 16–44 MPa and good elongation at break over 220% of PBFGAs, exceeding most biodegradable packaging materials. The increase of GA units slightly impacted the barrier properties, with reduced CO2 (53×) and O2 (15×) permeability coefficients than those of commercial PBAT films, and also better than those of PET. The hydrolysis of the glycolate was restrained by steric hindrance of furan rings, while in enzymatic degradation PBFGAs displayed obvious weight loss with GA units ＞20 mol%. With superior thermal, tensile, barrier and degradable properties, PBFGAs have the potential to serve as promising and innovative bio-based polymers for eco-friendly and sustainable plastic packaging. [ABSTRACT FROM AUTHOR]

CdS quantum dots deposited on carbon nitride (g-C3N4) nanosheets have been synthesized by ultra-low temperature (−60 °C) liquid phase precipitation reactions. The obtained CdS quantum dots were uniformly distributed on the surface of the g-C3N4 nanosheets with an average diameter of 5 nm. Correspondingly, CdS/g-C3N4 exhibits a highly enhanced photocatalytic performance. [ABSTRACT FROM AUTHOR]

We report a fluorogenic probe for naked-eye sensing of hydrazine in solution and in the gaseous phase. The probe based on tetraphenylethylene (TPE) with aggregation-induced emission (AIE) characteristics shows OFF–ON fluorescence as observed by thin-layer chromatography (TLC) upon treatment with hydrazine. Specifically, the fluorescence of the probe was quenched due to the attached N=N group, which can be reduced to –NH–NH– in the presence of hydrazine to turn on the fluorescence. The reduced intermediate can be easily oxidized in air to regenerate the original probe for recyclable usage. Both fluorometric and colorimetric readings were achieved by TLC with high sensitivity and excellent selectivity. This study thus represents a simple example of a reusable and naked-eye molecular probe for monitoring environmental hazards. Finally, the probe has also been applied to detect hydrazine in live cells. [ABSTRACT FROM AUTHOR]

This article presents the Closing Remarks of the Faraday Discussion on aggregation induced emission (AIE) held in Guangzhou, China in November 2016. The history of the AIE phenomenon is summarized, from its discovery and mechanistic studies to real-life applications in optoelectronics, environmental monitoring and biomedical research. The paper concludes with comments on the future perspectives of the field. [ABSTRACT FROM AUTHOR]

Toxins and bacteria in water or food pose a threat to human life and could potentially be exploited for bioterrorism. Real-time naked-eye detection of these contaminants is highly desirable to provide a direct and simple analytical method and address the challenges of the existing strategies. Using the detection of ricin and B. subtilis as an example, a naked-eye multiplex detection model is established. In this work, a green fluorogen with aggregation-induced emission (AIE) characteristics was encapsulated in silica nanoshells. The resulting green AIE nanoparticles (NPs) were further functionalized with ricin binding aptamers (RBA), which were used together with graphene oxide (GO) to provide a fluorescence turn-on approach recognizable by naked eye for the specific sensing of ricin. The platform is compatible with a red emissive fluorescent light-up probe (AIE-2Van) for B. subtilis detection. The success of the multiplex is validated by different colours, that is, green for ricin and red for B. subtilis, which are clearly recognizable by naked eye in the same solution. [ABSTRACT FROM AUTHOR]

Paper-based assay is a promising alternative sensing technology due to its portability, low cost and ease of operation compared to the solution sensing method. Most of current fluorophores suffer from aggregation-caused quenching, which affects their signal output in the solid state. Although fluorogens with aggregation-induced emission (AIEgens) have attracted intense research interest for solution assays, they have been rarely employed for solid phase detection due to their high emissivity in the aggregated state. In this work, three fluorogens TPE-DCV, MTPE-DCV and NTPE-DCV were designed and synthesized by the integration of intramolecular charge transfer and AIE characteristics to fine-tune their absorption and emission maxima. Among the three AIEgens, NTPE-DCV gives the best response to hydrazine, with a detection limit of 143 ppb in solution. In addition, the NTPE-DCV stained paper strip offers fluorescence turn-on from dark to yellow for 1 mM hydrazine solution or 1% hydrazine vapor for naked-eye sensing. It was also found that the fluorogen with a stronger electron donor (e.g.NTPE-DCV) showed better selectivity to hydrazine over glutathione. The practical example of hydrazine detection elucidates a general strategy for the design of AIE probes that are compatible with both solution and paper-based assays with a high sensitivity and rapid signal readout. [ABSTRACT FROM AUTHOR]

The currently available photosensitizers (PSs) for photodynamic therapy (PDT) can easily lead to undesirable normal cell death due to their intrinsic photo-toxicity and lack of selectivity for cancer cells. Activatable PSs with high therapeutic efficiency towards cancer cells but minimized side effects on normal cells are thus highly desirable. In this work, we developed a probe with dual-targeted activatable PSs that can recognize and ablate cancer cells with high selectivity. The probe is composed of a fluorophore with aggregation-induced emission (AIE) characteristics which can be used as an imaging agent as well as a PS, a quencher moiety that can be cleaved upon encountering biothiols, and a cyclic arginine–glycine–aspartic acid (cRGD) tripeptide for targeting cancer cells with overexpressed αvβ3 integrin. The probe itself is non-fluorescent and its ability to generate reactive oxygen species (ROS) is prohibited. However, it could be selectively activated to offer specific fluorescence turn-on with efficient ROS generation in the aggregated state, which was used to ablate cancer cells overexpressing both αvβ3 integrin receptors and glutathione. As compared to conventional activatable PSs which show quenched fluorescence and reduced ROS generation in the aggregated state, the dual-selection process with enhanced fluorescence and efficient ROS generation of the activated AIE probe in aggregated state offers a high signal-to-background ratio for MDA-MB-231 cancer cell imaging and ablation. This strategy thus opens up new opportunities for designing activatable PSs with high selectivity and low intrinsic photo-toxicity for photodynamic cancer cell ablation. [ABSTRACT FROM AUTHOR]

A novel fluorescent probe SA-βGal is reported here with light-up response to β-galactosidase. SA-βGal possesses the β-galactopyranoside group to react with β-galactosidase and releases the fluorescent salicylaldehyde azine with both aggregation induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT) characteristics. The linear fluorescent response enables the in vitro quantification of β-galactosidase activity in a range of 0–0.1 U mL−1 with a detection limit of 0.014 U mL−1. The probe exhibits significant advantages, such as no self-quenching at high concentrations, a large Stokes shift (190 nm) and high specificity to β-galactosidase with an excellent light-up ratio of 820 fold. Moreover, thanks to its good retention in living cells, the application of SA-βGal for the imaging of cellular β-galactosidase was also achieved with high contrast. [ABSTRACT FROM AUTHOR]

We report the design and synthesis of a red fluorescent AIE light-up probe for selective recognition, naked-eye detection, and image-guided photodynamic killing of Gram-positive bacteria, including vancomycin-resistant Enterococcus strains. [ABSTRACT FROM AUTHOR]

A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PBC). PBC with 71% cis-CHRM exhibits good elasticity with shape recovery rates of 64% at 200% strain and 92% at break, tensile modulus, strength and elongation at break at 111 and 18 MPa and 1230%, respectively. [ABSTRACT FROM AUTHOR]

We report a fluorescent light-up platform for multi-target detection in aqueous solution and on paper strip. The platform is based on a salicylaldazine fluorogen with aggregation-induced emission (AIE) and excited state intramolecular proton transfer (ESIPT) characteristics, which shows distinct advantages including ease of chemical modifications, free of self-quenching effect, excellent light-up ratio and large Stokes shift. To demonstrate the versatility of the platform, palladium cation and perborate anion, as well as UV light, were selected as the targets. The three representative probes, AIE-Pd, AIE-perborate and AIE-UV, light up specifically in the presence of the target both in aqueous solution and on paper strip. The immediate naked-eye response makes the probes ideal for instrument-free and power-free detection. [ABSTRACT FROM AUTHOR]

In this work, SMPUs with non-planar ring structures in the hard segments display a low degree of phase separation but excellent shape recoverability (shape recovery rate ∼99% with 500% strain). The accepted wisdom is that there are two criteria for SMPUs possessing good shape recoverability: (i) high degree of phase separation forming physical crosslinks; (ii) strong physical interactions between hard segments which keep physical crosslinks stable under external stress. However, our results are completely against the accepted wisdom since the asymmetrical non-planar ring structures will depress the micro-phase separation and physical interactions in the hard phase. Thus, the excellent shape recovery could not be attributed to the phase morphology. Based on such results, single molecule force spectroscopy was adopted to study the properties of single polymer chains with non-planar ring structures. We found that the single chain elasticity was largely improved by non-planar rings. It is highly possible that the excellent shape recovery property originates from the elastic non-planar ring structures absorbing the external stress which stabilizes the physical crosslinks. Much work needs to be done in the near future to confirm this assumption. [ABSTRACT FROM AUTHOR]

One of the obvious shortcomings of bio-based shape memory polyurethanes (Bio-SMPUs), which usually use natural oil based polyols as the soft segment, is their low mechanical strength because the long dangling chains (six to eight carbons) in these polyols prevent the Bio-SMPUs from deep micro-phase separation, and consequently deteriorate their mechanical properties. In this work, we prepared a bio-based polyester diol for the soft segment, in which short side chains (C=C) were used to tune the transition temperature and the morphology of the Bio-SMPUs. The moderate concentration of short branch chains barely affects the micro-phase separation, and the mechanical properties of the Bio-SMPUs are quite satisfactory. With the same 70 wt% soft segment content, the tensile strength in this work is 13.2 MPa, while the one using ricinoleate-based soft segments reported 2.8 MPa. Through proper shape memory programming, the synthesized Bio-SMPUs show good shape memory properties with a shape fixing rate of greater than 98% and a shape recovery rate of 85% in the first cycle and greater than 90% in the following cycles. This study provides a framework for developing bio-based SMPUs with high mechanical and good shape memory properties at the same time. [ABSTRACT FROM AUTHOR]

Two kinds of rosin acid derivatives were synthesized to serve as the rigid monomers to copolymerize with acrylated epoxidized soybean oil (AESO). Full bio-based thermosetting resins with satisfactory properties were then prepared. For comparison, petroleum-based divinylbenzene (DVB) was also used to copolymerize with the same AESO. The chemical structures of the synthesized rosin derivatives were confirmed by 1H NMR, 13C NMR and FT-IR before polymerization. The mechanical and thermal properties of the resulting thermosets were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). Results demonstrated that the glass transition temperatures, tensile strength and modulus of the cured AESO were significantly improved after copolymerization with the rosin derivatives. The rosin acid derivatives showed great potential to replace petroleum-based rigid compounds for preparing soybean oil-based thermosets. The important information about how to design and synthesize more renewable thermosets with satisfactory properties was provided in this study. [ABSTRACT FROM AUTHOR]

Electrodynamic therapy (EDT) has recently emerged as an alternative approach for tumor therapy via the generation of ROS by platinum (Pt) nanoparticles under electric field. An interesting phenomenon observed during EDT is that the increased on-site concentration of chloride ions is highly beneficial for ROS generation and inhibition efficacy. Here, in this study, nanoclusters (KCC), consisting of potassium chloride (KCl) nanocrystals and amorphous calcium carbonate (CaCO 3 ), were synthesized and integrated with platinum nanoparticles (KCCP). In this system, KCC can dissolve and release calcium and chloride ions within tumor cells. The intracellular chloride ions considerably facilitated ROS generation by Pt nanoparticles under an electric field. More importantly, the excessive calcium ions and ROS formed a cycle of mutual promotion and self-amplification in cells, leading to agitated tumor inhibition, both in vitro and in vivo .

Defects in metal oxides can significantly improve their physical and chemical properties. However, the conventional methods to generate defects often require complex procedures and harsh conditions. In this study, we design a simple and room-temperature preparation route to prepare defective metal oxide nanoparticles with high yield. The formation of defects is attributed to the generation of oxygen vacancies (V O ) and hydrogenation caused by charge transfer at a Mg-metal oxide junction structure. Defective TiO 2 exhibits excellent performance toward wastewater cleaning and water splitting. The proposed route is promising in terms of convenience, low cost, and large-scale production.

CdS quantum dots deposited on carbon nitride (g-C 3 N 4 ) nanosheets have been synthesized by ultra-low temperature (-60 °C) liquid phase precipitation reactions. The obtained CdS quantum dots were uniformly distributed on the surface of the g-C 3 N 4 nanosheets with an average diameter of 5 nm. Correspondingly, CdS/g-C 3 N 4 exhibits a highly enhanced photocatalytic performance.

A targeted theranostic delivery system containing two prodrugs with drug tracking and activation monitoring functions was developed for visualizing cancer cell ablation with synergistic anticancer effects.

We report a general strategy to design and synthesize red fluorescent light-up probes for cellular imaging based on a fluorogen with intramolecular charge transfer characteristics.

Dissociation enhanced lanthanide fluoroimmunoassay (DELFIA) technique based on EDTA-Eu(3+) derivative biolabels is the most widely used time-resolved luminescence bioassay technique for clinical diagnosis, but its major drawback is that the conventional luminescence enhancement solution of EDTA-Eu(3+) requires UV excitation (<360 nm). In this work, three new visible-light-excited luminescence enhancement solutions are developed and their luminescence response behaviors to EDTA-Eu(3+) are systematically investigated. The new solutions were prepared by co-dissolving a newly synthesized tetradentate β-diketone, 1,2-bis[8'-(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)-naphth-2'-yl]-benzene (BHHNB), and one of three derivatives of triazine, 2-(N,N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine (DPBT), 2-(N,N-diethylanilin-4-yl)-4,6-bis(3-methylpyrazol-1-yl)-1,3,5-triazine (MPBT) or 2-(N,N-diethylanilin-4-yl)-4,6-bis(pyrazol-1-yl)-1,3,5-triazine (BPT), in a weakly acidic aqueous buffer at pH 3.2 containing 0.1% Triton X-100. These solutions showed sensitive and rapid luminescence responses to non-luminescent EDTA-Eu(3+) by the formation of the ternary Eu(3+) complexes, BHHNB-Eu(3+)-DPBT, BHHNB-Eu(3+)-MPBT and BHHNB-Eu(3+)-BPT. These complexes have long luminescence lifetimes (>500 μs) and a wide excitation wavelength range from UV to visible light with the excitation peaks at 390, 400 and 420 nm, respectively, which enabled the solutions to be used as visible-light-excited luminescence enhancement solutions for the highly sensitive time-resolved luminescence detection of EDTA-Eu(3+).