Efficient Solar-Driven Interfacial Water Evaporator using Hydrogel Modified Carbon-Based Biomass with Abundant Microchannels.

The conventional sea water desalination technologies are not yet adopted worldwide, especially in the third world countries due to their high capital cost as well as large energy requirement. To solve this issue in a sustainable way an interfacial solar water evaporation device is designed and proposed in this article using the branches of Prunus serrulata (PB). The PB has abundant microchannels and shows excellent photothermal conversion capability after carbonization. Moreover, the easy access to raw materials and the facile fabrication process makes the solar water evaporating device very cost effective for seawater desalination application. Experiments show that in the presence of the fabricated evaporator the evaporation rate of water can reach 3.5 kg m-2  h-1 under 1 sun, which is superior to many similar experimental devices. In addition, its advantages, such as effective sewage purification capability, low cost, and environmental friendliness, make this evaporator highly competitive in the extensive promotion of this technology and can be considered as a new sustainable solution for seawater desalination with great application potential and prospects.

Parkin regulates IGF2BP3 through ubiquitination in the tumourigenesis of cervical cancer.

BACKGROUND: Insulin-like growth Factor 2 mRNA-binding protein 3 (IGF2BP3) is a highly conserved RNA-binding protein and plays a critical role in regulating posttranscriptional modifications. METHODS: Immunoprecipitation was used to examine the interaction of Parkin and IGF2BP3. Mass spectrometry was performed to identify the ubiquitination sites of IGF2BP3. RNA-immunoprecipitation was conducted to examine the target genes of IGF2BP3. Xenograft mouse model was constructed to determine the tumorigenesis of IGF2BP3. RESULTS: IGF2BP3 expression is negatively correlated with Parkin expression in human cervical cancer cells and tissues. Parkin directly interacts with IGF2BP3, and overexpression of Parkin causes the proteasomal degradation of IGF2BP3, while knockdown of PARK2 increases the protein levels of IGF2BP3. Mechanistically, in vivo and in vitro ubiquitination assays demonstrated that Parkin is able to ubiquitinate IGF2BP3. Moreover, the ubiquitination site of IGF2BP3 was identified at K213 in the first KH domain of IGF2BP3. IGF2BP3 mutation results in the loss of its oncogenic function as an m6A reader, resulting in the inactivation of the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signalling pathways. In addition, IGF2BP3 mutation results in the attenuation of Parkin-mediated mitophagy, indicating its inverse role in regulating Parkin. Consequently, the tumourigenesis of cervical cancer is also inhibited by IGF2BP3 mutation. CONCLUSION: IGF2BP3 is ubiquitinated and regulated by the E3 ubiquitin ligase Parkin in human cervical cancer and ubiquitination modification plays an important role in modulating IGF2BP3 function. Thus, understanding the role of IGF2BP3 in tumourigenesis could provide new insights into cervical cancer therapy.

Multimodal energy harvesting and catalysis of piezoelectric nanosheets for efficient and round-the-clock wastewater treatment.

Solar-driven pollutants degradation is an important way for green wastewater treatment, but it is still limited by the intermittent solar flux. Here, we have prepared piezoelectric Bi4Ti3O12 (BTO) nanosheets with abundant physical properties, which can convert extensive solar energy, mechanical energy and temperature variation energy into electrical and chemical energy. It can be used for round-the-clock wastewater treatment by harvesting multi-modal energy. More importantly, the degradation rate of piezoelectric nanosheets can reach 153.4 × 10-3 min-1, and nanosheets can degrade many organic pollutants. In addition, we fabricate porous foam catalysts based on BTO-polydimethylsiloxane (PDMS) composite to prevent secondary contamination. Our results suggest that BTO nanosheets with photoelectric, piezoelectric and pyroelectric catalysis offer a potential approach for round-the-clock wastewater degradation by harvesting solar energy, ambient mechanical energy, and cyclic thermal energy.

Flexible multi-color electroluminescent devices with a high transmission conducting hydrogel and an organic dielectric.

Flexible electroluminescent devices have sparked widespread interest due to their tremendous applications in bioinspired electronics, smart wearables, and human-machine interfaces. In these applications, it is important to reduce the operating electrical frequency and realize color modulation. Herein, flexible electroluminescent devices have been fabricated with phosphor layers by a solution method. Using polyvinylidene difluoride as a dielectric layer and ionic hydrogels as electrodes, the devices can be effectively driven even when the operating frequency is 0.1 kHz. More importantly, the devices can exhibit multi-color emission, including blue, green, red and white. The results show that the developed devices are promising for flexible optoelectronics.

Selenide Heterostructure Nanosheets with Efficient Near-Infrared Photothermal Conversion for Therapy.

Photothermal therapy has been regarded as one of promising ways for tumor treatment. However, nanoagents with highly efficient thermal conversion and good bio-compatibility are still needed to be developed in biomedicine. In this work, we prepared two-dimensional heterostructures with bismuth selenide and tungsten selenide nanosheets as photothermal nanoagents. Near-infrared photothermal conversion of selenide heterostructure nanosheets can reach up to 40.75% under 808 nm excitation. It is known that selenium is a critical element to human health. More importantly, our experiments with mice show that the heterostructure nanosheets have low toxicity and high biocompatibility both in vitro and in vivo. The nanoagents based on heterostructures can effectively realize photothermal tumor ablation. It is suggested that the developed selenide nanosheets have great potential application in cancer therapy.

Multi-Mode Lanthanide-Doped Ratiometric Luminescent Nanothermometer for Near-Infrared Imaging within Biological Windows.

Owing to its high reliability and accuracy, the ratiometric luminescent thermometer can provide non-contact and fast temperature measurements. In particular, the nanomaterials doped with lanthanide ions can achieve multi-mode luminescence and temperature measurement by modifying the type of doped ions and excitation light source. The better penetration of the near-infrared (NIR) photons can assist bio-imaging and replace thermal vision cameras for photothermal imaging. In this work, we prepared core-shell cubic phase nanomaterials doped with lanthanide ions, with Ba2LuF7 doped with Er3+/Yb3+/Nd3+ as the core and Ba2LaF7 as the coating shell. The nanoparticles were designed according to the passivation layer to reduce the surface energy loss and enhance the emission intensity. Green upconversion luminescence can be observed under both 980 nm and 808 nm excitation. A single and strong emission band can be obtained under 980 nm excitation, while abundant and weak emission bands appear under 808 nm excitation. Meanwhile, multi-mode ratiometric optical thermometers were achieved by selecting different emission peaks in the NIR window under 808 nm excitation for non-contact temperature measurement at different tissue depths. The results suggest that our core-shell NIR nanoparticles can be used to assist bio-imaging and record temperature for biomedicine.

Multi-Responsive Sensor Based on Porous Hydrogen-Bonded Organic Frameworks for Selective Sensing of Ions and Dopamine Molecules.

Hydrogen-bonded organic frameworks (HOFs), as an emerging porous material, have attracted increasing research interest in fluorescence sensing due to their inherent fluorescence emission units with unique physicochemical properties. Herein, based on the organic building block 3,3',5,5'-tetrakis-(4-carboxyphenyl)-1,1'-biphenyl (H4TCBP), the porous material HOF-TCBP was successfully synthesized using hydrogen bond self-assembly in a DMF solution. The fluorescence properties of the HOF-TCBP solution showed that when the concentration was high, excimers were easily formed, the PL emission was red-shifted, and the fluorescence intensity became weaker. HOF-TCBP showed good sensitivity and selectivity to metal ions Fe3+, Cr3+, and anion Cr2O72-. In addition, HOF-TCBP can serve as a label-free fluorescent sensor material for the sensitive and selective detection of dopamine (DA). HOF-based DA sensing is actually easy, low-cost, simple to operate, and highly selective for many potential interfering substances, and it has been successfully applied to the detection of DA in biological samples with satisfactory recoveries (101.1-104.9%). To our knowledge, this is the first report of HOF materials for efficient detection of the neurotransmitter dopamine in biological fluids. In short, this work widely broadens the application of HOF materials as fluorescent sensors for the sensing of ions and biological disease markers.

Ratiometric thermometry using single Er3+-doped CaWO4phosphors.

Single doped CaWO4:Er3+phosphors were synthesized and studied for application of optical thermal sensing within a wide range of 98-773 K. Ratiometric strategy utilizing two luminescence intensity ratios, one between host and Er3+band (LIR1) and second between different Er3+transitions (LIR2), results in self-referencing temperature readouts. The presence of two temperature-dependent parameters could improve thermometric characteristics and broaden the working temperature range compared to a usual single-parameter thermometer. Thermometric performances of prepared samples were evaluated in terms of thermal sensitivities, temperature resolution and repeatability. The highest sensitivity of 2.09% K-1@300 K was found for LIR1, whereas LIR2provided more accurate thermal sensing with a temperature resolution of 0.06-0.1 K. Effect of Er3+doping concentration on sensing properties were studied. The presented findings indicate that CaWO4:Er3+phosphors are perspective in dual-mode thermal sensing with high sensitivity and sub-degree resolution.

Bio-Derived Photothermal Materials and Evaporators for Sustainable Solar Energy-Driven Water Process.

Interfacial solar steam generation (ISSG) is considered as an excellent seawater desalination technology because of its electricity-independent nature, low cost, and portability. However, improving the water evaporation efficiency, simplifying the fabrication process, and reducing the overall cost of the evaporator are still challenging. Here, an efficient and sustainable solar water evaporator is fabricated with carbonized ginkgo biloba leaves as the structural basis of photothermal materials. The combination of the abundant capillary channels in ginkgo leaves paired with polyacrylamide (PAM) hydrogel accelerates water transportation and solar-driven evaporation. The fabricated evaporator shows excellent photothermal conversion capability and evaporates water at 2.39 kg m-2 h-1 under 1 sun irradiation. In addition, the device exhibits remarkable stability in simulated seawater and can effectively realize seawater desalination or sewage treatment. As a result, the system is promising for future highly efficient solar evaporation due to its environmental protection and low cost.

Dual-mode nanophotonic upconversion oxygen sensors.

Nanophotonic biosensors capable of being excited in the NIR spectrum have applications in various sectors. Here, we develop a 980 nm-excitable nanophotonic sensor for real-time oxygen detection in both water and air by analyzing the photoluminescence lifetime and intensity using a nanocomposite of lanthanide-doped NaYF4:Yb3+,Tm3+ upconversion nanoparticles and a PtTFPP platinum porphyrin complex in a polystyrene matrix. Excellent overlap between the emission of the upconversion nanoparticles and the excitation band of the PtTFPP guarantees 68% efficient excitation of the PtTFPP molecules with a 980 nm NIR laser. For the first time, the oxygen sensitivity of the upconversion nanoparticles alone was reported, and it was demonstrated that the PL lifetime-based sensitivity slope was boosted more than 10 times by adding PtTFPP oxygen-sensitive molecules due to the energy transfer from the upconversion nano-emitters. In addition, the functionality of the upconversion-based sensor was investigated by analyzing its sensitivity, stability, reversibility, and temperature-dependent lifetime in both water and air, and its performance was compared with that of the sensor exposed to direct excitation at 410 nm. More importantly, the sensor was implanted under the skin of a chicken, and it was demonstrated that the PL intensity was amplified more than 12 times by employing the 980 nm excitation laser instead of 410 nm laser light. Therefore, excellent emission of the sensor under the skin paves the way for the development of implantable oxygen sensor platforms.

Double-doped YVO4 nanoparticles as optical dual-center ratiometric thermometers.

Crystalline inorganic nanoparticles doped with rare earth ions are widely used in a variety of scientific and industry applications due to the unique spectroscopic properties. The temperature dependence of their luminescence parameters makes them promising candidates for self-referencing thermal sensing. Here we report single phase YVO4 nanoparticles doped with different pairs of rare earth ions (Nd3+/Er3+, Tm3+/Er3+ and Nd3+/Tm3+) for contactless ratiometric thermometry within a wide temperature range of 298-573 K. The presence of dual luminescence centers in the optical thermometer allows one to circumvent the fundamental limitation of sensitivity inherent to thermometers based on thermally coupled levels. Important parameters for temperature sensing, such as relative thermal sensitivity and temperature resolution, were calculated for all synthesized samples and compared with the literature data. The YVO4:Tm3+,Er3+ sample displayed a relative sensitivity of 0.28% K-1 at room temperature, and the YVO4:Nd3+,Er3+ phosphor exhibited a high sensitivity of 0.56% K-1 at 573 K, while YVO4:Nd3+,Tm3+ demonstrated sub-degree thermal resolution. These findings demonstrate the good potential of dual-center ratiometric YVO4 thermometers and open the way toward future enhancement of their thermometric performances through variation of the doping concentration.

Nonvolatile modulation of luminescence in perovskite oxide thin films by ferroelectric gating.

Nonvolatile and giant modulation of luminescence can be realized by the ferroelectric gating effect in a Ga3+/Pr3+ co-doped BaTiO3 ultra-thin film epitaxially grown on a [Pb(Mg1/3Nb2/3)O3]0.7-[PbTiO3]0.3 single-crystallized substrate. The change behavior of the emission intensity matches that of the ferroelectric polarization hysteresis loop with a giant enhancement of over 13 times with negative polarization orientation. The interaction of O2- at the O2p orbital in the valence band and Pr3+ with injected holes by the ferroelectric gating effect promotes the formation of excited state O-, Pr4+, or Pr3+q. This ferroelectric gating method can promote the development of controllable photo-, electroluminescent, and other optoelectronic devices for display, sensing, communication, and so on.

Reconfigurable hybrid silicon waveguide Bragg filter using ultralow-loss phase-change material.

Reconfigurable silicon photonic devices attract much research attention, and hybrid integration with tunable phase-change materials (PCMs) exhibiting large refractive index contrast between amorphous (Am) and crystalline (Cr) states is a promising way to achieve this goal. Here, we propose and numerically investigate a Sb2Se3-Si hybrid waveguide Bragg filter operating in the telecom C-band on the silicon-on-insulator (SOI) platform. The proposed device consists of a Bragg grating (BG) with a thin top layer of ultralow-loss Sb2Se3 PCM interacting with evanescent field of the silicon waveguide mode. By harnessing the ultralow-loss and reversible index change of Sb2Se3 film, the spectral response of the hybrid BGs could be dynamically tuned. We also theoretically investigate the reversible phase transitions between Am and Cr states of Sb2Se3 film that could be attained by applying voltage pulses on the indium-tin-oxide (ITO) strip heater covered on Sb2Se3 film. Thermal simulations show that a 2 V (4.5 V) pulse with a duration of 400 ns (55 ns) applied to electric contacts would produce crystallization (or amorphization). The proposed structure may find great potential for on-chip phase tunable devices on a silicon platform.

Blue and white light modulation of a flexible electroluminescent device based on phosphors.

Flexibility, certain mechanical strength, and color modulation are significant elements for flexible optoelectronic devices. However, it is laborious to fabricate a flexible electroluminescent device with balanceable flexibility and color modulation. Here, we mix a conductive nonopaque hydrogel and phosphors to fabricate a flexible alternating current electroluminescence (ACEL) device with color modulation ability. This device realizes flexible strain based on polydimethylsiloxane and carboxymethyl cellulose/polyvinyl alcohol ionic conductive hydrogel. The color modulation ability is achieved by varying the voltage frequency applied on the electroluminescent phosphors. The color modulation could realize blue and white light modulation. Our electroluminescent device exhibits great potential in artificial flexible optoelectronics.

Lanthanide-Doped Topological Nanosheets with Enhanced Near-Infrared Photothermal Performance for Energy Conversion.

Two-dimensional inorganic semiconductor materials have aroused tremendous research interest and found their potential in resolving the present urgent global issues, such as cancer therapy and fresh water shortage. Particularly, the near-infrared (NIR) photothermal conversion efficiency is a significant parameter in photothermal therapy. However, lack of an effective improvement strategy and their relatively low NIR phothermal conversion efficiency would restrict their wide and further application. Here, this work reports that enhanced NIR photothermal conversion is achieved in topological Bi2Se3 nanosheets by introducing a lanthanide dopant. Specifically, lanthanide Pr-doped Bi2Se3 nanosheets possess a photothermal conversion efficiency of 49.5%, which is higher than those of undoped Bi2Se3 nanosheets (31.0%) and numerous reported photothermal materials. The electronic structure of Pr-doped Bi2Se3 nanosheets was also analyzed by first-principles simulation. Furthermore, an interfacial evaporation system based on the developed nanosheets has been established, demonstrating a superior solar-thermal conversion efficiency of 91.5% and a water evaporation rate of 1.669 kg m-2 h-1 under 1 sun irradiation. The present work would provide new insights for the increase in the efficiency of photothermal materials.

Fabrication of large size individual octahedral tungsten oxide hydrate and Au NPs as SERS platforms for sensitive detection of cytochrome C.

Surface-enhanced Raman scattering (SERS) has attracted much attention with its powerful trace detection and analysis capabilities, especially biological and environmental molecules. However, building a protein SERS detection platform based on semiconductor devices is a huge challenge. Herein, through the synergy of NH3 and nickel foam, a large-sized semiconductor tungsten oxide hydrate platform (WOHP) was synthesized. The crystal plane of a single WOHP particle is larger than the excitation spot. As a SERS substrate, WOHP can make full use of the excitation light without destroying the structure during the protein molecules detection process. Through the synergy of WOHP and Au NPs, the enhancement factor is 1.5 × 104. Raman peaks of WOHP can be used as references for the detection of typical protein cytochrome C (Cyt C). As the Cyt C concentration decreases, the ICyt C/IWOHP ratio decreases, and the signal can still be obtained when the concentration is as low as 5 × 10-9 mol L-1. More importantly, the method does not affect the catalytic activity of Cyt C and can be applied to the detection of Cyt C concentration in serum.

Ultrabroadband Tuning and Fine Structure of Emission Spectra in Lanthanide Er-Doped ZnSe Nanosheets for Display and Temperature Sensing.

Realizing multicolored luminescence in two-dimensional (2D) nanomaterials would afford potential for a range of next-generation nanoscale optoelectronic devices. Moreover, combining fine structured spectral line emission and detection may further enrich the studies and applications of functional nanomaterials. Herein, a lanthanide doping strategy has been utilized for the synthesis of 2D ZnSe:Er3+ nanosheets to achieve fine-structured, multicolor luminescence spectra. Simultaneous upconversion and downconversion emission is realized, which can cover an ultrabroadband optical range, from ultraviolet through visible to the near-infrared region. By investigating the low-temperature fine structure of emission spectra at 4 K, we have observed an abundance of sublevel electronic energy transitions, elucidating the electronic structure of Er3+ ions in the 2D ZnSe nanosheet. As the temperature is varied, these nanosheets exhibit tunable multicolored luminescence under 980 and 365 nm excitation. Utilizing the distinct sublevel transitions of Er3+ ions, the developed 2D ZnSe:Er3+ optical temperature sensor shows high absolute (15.23% K-1) and relative sensitivity (8.61% K-1), which is superior to conventional Er3+-activated upconversion luminescent nanothermometers. These findings imply that Er3+-doped ZnSe nanomaterials with direct and wide band gap have the potential for applications in future low-dimensional photonic and sensing devices at the 2D limit.

Reversible modification of ultra-broadband luminescence in transparent photonic materials through field-induced nanoscale structural transformation.

The development of integrated multifunctional materials with transparent characteristics meets the requirements of optoelectronics and communication. The coupling of stimuli-responsive materials has become a frequently considered strategy. Experimentalists not only search for photonic materials with excellent physical and chemical properties, but also pursue precise and reversible spectral modification. In this study, the luminescent center Ni2+ is artificially introduced into the transparent LiNbO3 nanoferroelectric photonic materials. The Ni2+ ion-based transparent photonic materials exhibit novel complete ultra-broadband emission in the whole near-infrared region. Until now, the ultra-broadband emission was realized by codoping of several active doping ions. In addition, the emission intensity and wavelength of the luminescent center are modified accurately and reversibly by field-induced nanoscale structural transformation. The Ni2+ ion-based transparent nanoferroelectric photonic materials provide an easy way to develop tunable lasers and ultra-broadband optical amplifiers.

Yb/Ho Codoped Layered Perovskite Bismuth Titanate Microcrystals with Upconversion Luminescence: Fabrication, Characterization, and Application in Optical Fiber Ratiometric Thermometry.

Optical thermometry has attracted great interest owing to its noncontact and fast responsive properties in practical applications. However, some sensing errors may occur in many optical ratiometric thermometers due to the overlap of emission peaks, suggesting the necessity of developing excellent luminescent materials. Here, we report the fabrication and characterization of Bi4Ti3O12:Yb/Ho for ratiometric thermometry. Bismuth titanate was selected as the matrix due to its low phonon energy, high machinability, and satisfactory thermal stability. The temperature sensing was constructed on the intensity ratio of the two upconversion emission bands with wide separation in Bi4Ti3O12:Yb/Ho under 980 nm excitation. The wide separation endows the materials with high signal discrimination for temperature detection. The developed materials were characterized in terms of crystal structure, reflectance, and emission spectra for thermometry application. The maximum relative sensitivity was shown to be as high as 2.11% K-1. More importantly, an optical fiber thermometry was developed based on the fabricated microcrystals, which can find its potential applications in harsh environments.

Exceptional modulation of upconversion and downconversion near-infrared luminescence in Tm/Yb-codoped ferroelectric nanocomposite by nanoscale engineering.

The emission properties of lanthanide ions have been extensively investigated for their interesting physical processes and enormous applications. Conventional strategies have been used to modify luminescence properties such as temperature, pressure, and modifying components. However, the traditional methods are volatile and irreversible, which is unconducive for some optoelectronic applications. In this article, the electromechanical softness of the ferroelectric lattice is employed, which makes the strong coupling relationship between the electric field and the photonic properties of lanthanide ions. The emission intensity of the Tm3+:3H4-4H6 and 3F4-4H6 transitions was exceptionally enhanced by 2.6 and 3.2 times via ferroelectric polarization, respectively. Meanwhile, the luminescence response presents excellent reversibility and nonvolatility. This study provides a unique proposal for designing highly integrated stimuli-responsive photonic materials toward a variety of applications.