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Highlights: A strategy that combines multi-mode scanning probe microscopy-based electrical characterization and nano-infrared spectroscopy is developed. A series of samples with different coupling agents and nanoparticles are characterized to unveil the local structure-property correlation of the interface in ferroelectric polymer nanocomposites. The formation of hydrogen bond between the surface modifiers and the ferroelectric polymer enhances the β-phase content and reduces the domain size of the interface, and hence promotes the local piezoelectric effect and breakdown strength. Ferroelectric polymer nanocomposites possess exceptional electric properties with respect to the two otherwise uniform phases, which is commonly attributed to the critical role of the matrix–particle interfacial region. However, the structure–property correlation of the interface remains unestablished, and thus, the design of ferroelectric polymer nanocomposite has largely relied on the trial-and-error method. Here, a strategy that combines multi-mode scanning probe microscopy-based electrical characterization and nano-infrared spectroscopy is developed to unveil the local structure–property correlation of the interface in ferroelectric polymer nanocomposites. The results show that the type of surface modifiers decorated on the nanoparticles can significantly influence the local polar-phase content and the piezoelectric effect of the polymer matrix surrounding the nanoparticles. The strongly coupled polar-phase content and piezoelectric effect measured directly in the interfacial region as well as the computed bonding energy suggest that the property enhancement originates from the formation of hydrogen bond between the surface modifiers and the ferroelectric polymer. It is also directly detected that the local domain size of the ferroelectric polymer can impact the energy level and distribution of charge traps in the interfacial region and eventually influence the local dielectric strength. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel fluorogenic RNA aptamer output sensor via in vitro transcription (IVT) activated by RPA (ROSAR) was developed. • The proposed ROSAR for pathogens nucleic acid (DNA or RNA) testing displayed outstanding performance. • A paper-based ROSAR was developed for improving the stability of reagents and facilitate POC testing. • An integrated, low-cost, and user-friendly device was designed for paper-based ROSAR readout using mobile phone. • The proposed ROSAR and paper-based ROSAR were validated using clinical samples, showed the potential of clinical application. Sensitive, simple, and rapid nucleic acid testing used for pathogen detection are crucial for preventing outbreaks and transmission of infectious diseases. In this study, we present a fluorogenic RNA aptamer Output Sensors via transcription Activated by Recombinase polymerase amplification (RPA), termed ROSAR, for highly sensitive detection of DNA and RNA from pathogenic bacteria or viruses in clinical samples. The promoter primer and reporter primer facilitate the integration of the transcriptional promoter with the fluorogenic RNA aptamer transcription templates through the RPA of target DNA. Subsequently, the amplification products are transcribed by T7 RNA polymerase, producing RNA aptamer that binds to a fluorogenic dye. The assay, which can be completed within 50 min and can allow a limit of detection of level aM nucleic acid concentration, owning to the dual amplification effects of RPA and in vitro transcription. Furthermore, we develop a paper-based ROSAR by freeze-drying the reaction components, which is compatible with visual detection based on mobile phone fluorescent reader and suitable for point-of-care (POC) applications. The assay can detect various viral and bacterial nucleic acids, making it a highly promising tool for large-scale epidemic screening and rapid POC testing in home healthcare settings. [ABSTRACT FROM AUTHOR]

The control of contagious or refractory diseases requires early, rapid diagnostic assays that are simple, fast, and easy-to-use. Here, easy-to-implement CRISPR/Cas12a-based diagnostic platform through Raman transducer generated by Raman enhancement effect, term as SERS-CRISPR (S-CRISPR), are described. The S-CRISPR uses high-activity noble metallic nanoscopic materials to increase the sensitivity in the detection of nucleic acids, without amplification. This amplification-free platform, which can be performed within 30–40 min of incubation time, is then used for detection of SARS-CoV-2 derived nucleic acids in RNA extracts obtained from nasopharyngeal swab specimens (n = 112). Compared with the quantitative reverse transcription polymerase chain reaction (RT-qPCR), the sensitivity and specificity of S-CRISPR reaches 87.50% and 100%, respectively. In general, the S-CRISPR can rapidly identify the RNA of SARS-CoV-2 RNA without amplification and is a potential strategy for nucleic acid point of care test (POCT). [ABSTRACT FROM AUTHOR]

Lateral flow immunoassay (LFIA) is one of the most common analytical platforms for point-of-care testing (POCT), which is capable of large-scale primary screening and home self-testing of infectious diseases. However, the sensitivity of conventional AuNPs-based LFIA is relatively low and more prone to false negatives. Herein, we report a novel LFIA based on gold-core-silver-shell bimetallic nanoparticles (Au4-ATP@Ag NPs) emitting Surface-enhanced Raman scatting (SERS) and Photothermal (PT) effect, named SERS/PT-based dual-modal LFIA (SERS/PT-dmLFIA), for the antigen detection of infectious diseases pathogens, which displayed an excellent performance. For influenza A virus (IAV), influenza B virus (IBV), and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) N protein detection, the limit of detections (LoD) with Raman as signal were 31.25, 93.75, and 31.25 pg mL-1 respectively, and the LoDs with temperature difference (∆ T) as signal were as low as 15.63, 187.5, and 15.63 pg mL-1 respectively, which were over 4-fold more sensitive than visual-based LFIA. The proposed SERS/PT-dmLFIA was used for detecting virus antigen in pharyngeal swabs and showed ideal coincidence rate of over 95% compared to the commercialized assays. In addition, we explored the development of multiplex SERS/PT-dmLFIA that can detect IAV, IBV, and SARS-CoV-2 antigens simultaneously without cross reactivity. Overall, the SERS/PT-dmLFIA for antigen detection not only exhibits high sensitivity, accuracy and specificity, but also have characteristics of rapidity and simplicity, which holds high potential for rapid diagnosis of infectious diseases in laboratory testing, mass screening, and home self-testing. • SERS/photothermal (PT)-based dual-modal lateral flow immunoassay was developed. • Bimetallic nanomaterials were used as probes displayed excellent PT and SERS effect. • The proposed LFIA for virus antigen detection displayed outstanding performance. • The dual-modal LFIAs were validated using clinical pharyngeal swab samples. • The multiplex LFIA achieved IAV, IBV, and SARS-CoV-2 antigens simultaneous detection. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) have established their promising application as infrared photodetector and the photothermoelectric (PTE) effect is demonstrated to play a critical role. While extensive studies are focused on the optoelectronic behaviors, the thermoelectric conversion involved in the PTE has been pursued to less extent probably due to the overall low thermopower under infrared (IR) illumination. Herein, to trigger a stronger PTE response, Au/CNT heterojunctions are formed by Au nanoparticles (NPs) decoration of CNT films to facilitate both light absorption and carrier transportation, so that thermoelectric property is enhanced simultaneously. Significant boost on infrared radiation energy conversion capability is therefore enabled in Au NPs decorated CNT film, delivering maximum output voltage of 26.1 mV and power of 27.3 µW, outperforming the state‐of‐the art photodetectors based on PTE effect. The transport mechanism is revealed via combining in situ Kelvin Probe Force Microscope mapping of the surface potential and macroscopic transport and output performances under IR illumination. Finally, the IR detection function is validated via an 8‐channel IR detector prototype, presenting sensitive responsivity and long‐term cyclic stability. The study thus demonstrates the PTE effect as a promising platform toward high‐performance optoelectronic applications such as IR detection and solar energy harvesting. [ABSTRACT FROM AUTHOR]

Group A Streptococcus (GAS), a major pathogen, causes various respiratory diseases with substantial morbidity and mortality worldwide. In this study, we develop an immunoassay for the early screening and diagnosis of GAS infections. A latex beads-based lateral flow immunoassay (LBs-LFIA) and a fluorescent beads-based LFIA (FBs-LFIA) using an antibody cocktail that was coated on the test line (T line), the limit of detection (LoD) of LBs-LFIA was 105 CFU mL−1 and FBs-LFIA was 103 CFU mL−1. Furthermore, the use of the antibody cocktail led to the detection of the various epidemic clinical types of GAS with high sensitivity (100%) and specificity (＞95%). To devise a point-of-care testing (POCT) platform for mass screening in low-resource areas, a mobile phone-based portable strip reader capable of visually interpreting the results was developed and the LoD of LBs-LFIA and FBs-LFIA were calculated as 104 CFU mL−1 and 102 CFU mL−1, respectively. Taken together, we suggest that the developed LBs-LFIA and FBs-LFIA using the antibody cocktail can be used for the clinical emergency detection of GAS infections. [Display omitted] • The strategy of antibody cocktail was firstly used to immunodetection of GAS. • A mobile phone-based portable device was designed for reading GAS LFIA. • The two LFIAs can be used to detect different subtypes of GAS. • The two LFIAs were able to detect the presence of GAS in throat swab samples. [ABSTRACT FROM AUTHOR]

Early rapid screening diagnostic assay is essential for the identification, prevention, and evaluation of many contagious or refractory diseases. The optical density transducer created by platinum nanoparticles (PtNPs) (OD-CRISPR) is reported in the present research as a cheap and easy-to-execute CRISPR/Cas12a-based diagnostic platform. The OD-CRISPR uses PtNPs, with ultra-high peroxidase-mimicking activity, to increase the detection sensitivity, thereby enabling the reduction of detection time and cost. The OD-CRISPR can be utilized to identify nucleic acid or protein biomarkers within an incubation time of 30–40min in clinical specimens. In the case of taking severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) N gene as an instance, when compared to a quantitative reverse transcription-polymerase chain reaction (RT-qPCR), the OD-CRISPR test attains a sensitivity of 79.17% and a specificity of 100%. In terms of detecting prostate-specific antigen (PSA), aptamer-based OD-CRISPR assay achieves the least discoverable concentration of 0.01 ng mL−1. In general, the OD-CRISPR can detect nucleic acid and protein biomarkers, and is a potential strategy for early rapid screening diagnostic tools. [Display omitted] • A noble metal nanocatalysts-based CRISPR/Cas12a assay (OD-CRISPR) is reported. • The OD-CRISPR is used for the detection of nucleic acid in clinical samples. • The aptamer-based OD-CRISPR is used for the detection of protein in clinical samples. [ABSTRACT FROM AUTHOR]

The performance of a flexible transparent conductive electrode with extremely smooth topography capable of withstanding thermal processing at 300 °C for at least 6 h with little change in sheet resistance and optical clarity is reported. In depth investigation is performed on atomic layer deposition (ALD) deposited ZnO on Ag nanowires (NWs) with regard to thermal and atmospheric corrosion stability. The ZnO coated nanowire networks are embedded within the surface of a polyimide matrix, and the <2 nm roughness freestanding ­electrode is used to fabricate a white polymer light emitting diode (PLED). PLEDs obtained using the ZnO-AgNW-polyimide substrate exhibit comparable performance to indium tin oxide (ITO)/glass based devices, verifying its efficacy for use in optoelectronic devices requiring high processing temperatures. [ABSTRACT FROM AUTHOR]

Ultrasensitive and quantitative detection using simple and low-cost assays is critical in clinical diagnostics. In this report, we developed a triangular silver nanoprism (AgNPRs) etching-based plasmonic biosensor for the detection of cancer biomarkers. The triangular AgNPRs-based plasmonic biosensor is an enzyme-linked immunosorbent assay combined with the enzyme-mediated surface plasmon resonance (SPR) of triangular AgNPRs. Triangular AgNPRs uses the immune response of prostate-specific antigen (PSA) to trigger the glucose oxidase (GOx)-catalysed oxidation of glucose (Glu), producing hydrogen peroxide. Hydrogen peroxide acts as an oxidant to etch the triangular AgNPRs into smaller spherical silver nanoparticles, which is accompanied by a substantial blueshift of the SPR peak and a colourimetric blue-to-purple change that can be observed by the naked eye. The SPR peak shift enables the quantitative assessment of PSA due to the remarkable colour change. The triangular AgNPRs-based plasmonic ELISA approach exhibited a quasilinear response to logarithmic PSA concentrations in the range of 10 fg/mL to 100 pg/mL with a limit of detection (LOD) of 4.1 fg/mL. In addition, the LOD of PSA in this approach exceeds that of the conventional HRP-based ELISA (1.25 ng/mL) approach by more than 5 orders of magnitude. Patient serum samples from 16 donors were assayed with triangular AgNPRs-based plasmonic ELISA. The results from the triangular AgNPRs-based immunoassay and the time-resolved fluorescence immunoassay showed excellent correlation, and there were no significant differences in the quantified amounts of PSA. The triangular AgNPRs-based plasmonic ELISA approach has advantages (ultrasensitive, cost-effective, ease of operation) that are expected to be of great interest in diagnostics and to be suitable for a point-of-care test. [ABSTRACT FROM AUTHOR]

It has been a challenge to develop a new transparent conductor to replace the brittle and expensive indium tin oxide (ITO) film to make film heater with high transmittance in the visible wavelength range, high surface conductivity and mechanical flexibility. Here, we report the synthesis of a transparent composite film comprising a silver nanowire (AgNW) percolation network inlaid in the surface of a heat-resistant polymer film. This composite conductor has a figure-of-merit sheet resistance of 25 Ω · sq−1 with 86.4% transmittance at 550 nm. The composite film possesses outstanding heat-resistant property and can generate high temperature up to 230 °C at low operation voltages as an efficient thin film heater. Compared with the film heaters previously reported, the composite film heater shows faster heating response and higher saturation temperature under the same input voltage. The film heater could be bent to 10 mm diameter and the generated temperature decreased by less than 3 °C after 3 000 bending cycles. [ABSTRACT FROM AUTHOR]

The emergence of devices that combine elasticity with electronic or optoelectronic properties offers exciting new opportunities for applications, but brings significant materials challenges. Here, we report the fabrication of an elastomeric polymer light-emitting device (EPLED) using a simple, all-solution-based process. The EPLED features a pair of transparent composite electrodes comprising a thin percolation network of silver nanowires inlaid in the surface layer. The resulting EPLED, which exhibits rubbery elasticity at room temperature, is collapsible, and can emit light when exposed to strains as large as 120%. It can also survive repeated continuous stretching cycles, and small stretching is shown to significantly enhance its light-emitting efficiency. The fabrication process is scalable and was readily adapted for the demonstration of a simple passive matrix monochrome display featuring a 5 × 5 pixel array. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis of graphene oxide (GO) sheets with controlled size on a large scale was developed using chemical exfoliation by simply controlling the oxidation and exfoliation procedure. The GO samples prepared under different conditions, which all have excellent water dispersion, are characterized by thermal gravimetric analysis, Ultraviolet–visible spectroscopy, X-ray diffraction and atomic force microscopy. It is found that as longer oxidation times and more oxidants are used, the mean size of the GO sheets, which has a Gaussian distribution, decreases from ∼59,000 to ∼550nm2. [Copyright &y& Elsevier]

Abstract: Composites based on graphene-based sheets have been fabricated by incorporating solution-processable functionalized graphene into an epoxy matrix, and their electromagnetic interference (EMI) shielding studies were studied. The composites show a low percolation threshold of 0.52vol.%. EMI shielding effectiveness was tested over a frequency range of 8.2–12.4GHz (X-band), and 21dB shielding efficiency was obtained for 15wt% (8.8vol.%) loading, indicating that they may be used as lightweight, effective EMI shielding materials. [Copyright &y& Elsevier]

The number of CD8+ T lymphocytes (CD8 cells) in peripheral blood can directly reflect the immune status of the body and is widely used for auxiliary diagnosis and prognostic evaluation of diseases. There is an urgent need to develop a simple CD8 cell-counting platform to meet clinical needs. Our group designed a paper-based cell-counting method based on a blocking competition strategy. In addition, we developed a time-resolved fluorescence-blocking competitive lateral flow immunoassay (TRF-BCLFIA) for point-of-care CD8 cell counting that functions by measuring europium nanoparticle (EuNP)-labeled CD8 antibody probes that are not captured by CD8 cells, and we indirectly calculated the concentration of CD8 cells in samples. Within 30 min, four operation steps can provide an accurate CD8 cell count for a 75-μL whole-blood sample, and this approach can be implemented on a handheld device. The TRF-BCLFIA reliably quantified CD8 cells in whole-blood samples, in which the assay exhibited a linear correlation (R2 = 0.989) readout for CD8 cell concentrations ranging from 137 to 821 cells/μL. To validate this approach, our newly developed CD8 cell-counting tool was used to assess 33 tumor patient blood samples. The results showed a high consistency with a flow cytometry-based absolute count. This analysis approach is a promising alternative for the costly standard flow cytometry-based tools for CD8 cell counting in tumor patients in community clinics, small hospitals, and low medical resource regions. This technology would deliver simple diagnostics to patients anywhere in the world, regardless of geography or socioeconomic status. [Display omitted] • We developed a CD8 cell-counting tool that called time-resolved fluorescence-blocking competitive lateral flow immunoassay. • The probes labeled CD8 antibody was europium nanoparticle (EuNP). • Within 30 min, the TRF-BCLFIA reliably quantified CD8 cells in whole-blood samples with a good a linear correlation. • The TRF-BCLFIA showed a high consistency with a flow cytometry-based absolute count. [ABSTRACT FROM AUTHOR]

Designing autonomously oscillating materials is highly desirable for emerging smart material fields but challenging. Herein, a type of hypercrosslinked metal–organic polyhedra (HCMOPs) membranes formed by covalent crosslinking of boronic acid‐modified Zr‐based MOPs with polyvinyl alcohol (PVA) are rationally designed. In these membranes, MOPs serve as high‐connectivity nodes and provide dynamic borate bonds with PVA in hypercrosslinked networks, which can be broken/formed reversibly upon the stimulus of water vapor. The humidity response characteristic of HCMOPs promotes their self‐oscillating and self‐healing properties. HCMOP membranes can realize a self‐oscillating property above the water surface even after loading a cargo that is 1.5 times the weight of the membrane due to the fast adsorption and desorption kinetics. Finally, the HCMOP actuator can realize energy conversion from mechanical energy into electricity when coupled with a piezoelectric membrane. This work not only paves a new avenue to construct MOP‐polymer hybrid materials but also expands the application scopes of MOPs for smart actuation devices. [ABSTRACT FROM AUTHOR]

In this study, twenty-nine coumarin-3-sulfonamide derivatives, twenty-seven of which are original were designed and synthesized. Cytotoxicity assay indicated that most of these derivatives exhibited moderated to good potency against A549 cells. Among them, compound 8q showed potent inhibition against the four tested cancer cell lines, especially A549 cells with IC 50 value of 6.01 ± 0.81 μM, and much lower cytotoxicity on the normal cells was observed compared to the reference compounds. Bioinformatics analysis revealed human carbonic anhydrase IX (CAIX) was highly expressed in lung adenocarcinoma (LUAD) and associated with poor prognosis. The inhibitory activity of compound 8q against CAIX was assessed by using molecular docking and molecular dynamics simulations, which revealed prominent interactions of both compound 8q and CAIX at the active site and their high affinity. The results of ELISA assays verified that compound 8q possessed strong inhibitory activity against CAIX and high subtype selectivity, and could also down-regulate the expression of CAIX in A549 cells. Furthermore, the significant inhibitory effects of compound 8q on the migration and invasion of A549 cells were also found. After treatment with compound 8q , intracellular reactive oxygen species (ROS) levels increased and mitochondrial membrane potential (MMP) decreased. Mechanistic investigation using western blotting revealed compound 8q exerted the anti-migrative and anti-invasive effects probably through mitochondria-mediated PI3K/AKT pathway by targeting CAIX. In summary, coumarin-3-sulfonamide derivatives were developed as potential and effective CAIX inhibitors, which were worthy of further investigation. • Twenty-nine coumarin-sulfonamide derivatives were designed and synthesized. • Compound 8q had potent anticancer activity against A549 cells with good safety. • Compound 8q exhibited strong inhibition against CAIX and high subtype selectivity. • Compound 8q could also down-regulate the expression of CAIX in A549 cells. • The mechanism of action of compound 8q by targeting CAIX was elucidated. [ABSTRACT FROM AUTHOR]

Compact solid‐state refrigeration systems that offer a high specific cooling power and a high coefficient of performance (COP) are desirable in a wide range of applications where efficient and localized heat transfer is required. Here, a double‐unit electrocaloric (EC) polymer‐based refrigeration device with high intrinsic thermodynamic efficiency is demonstrated using a flexible EC polymer film with improved performance by doping plasticizer and an electrostatic actuation mechanism. The double‐unit refrigeration device achieves a large temperature span of 4.8 K, which is 71% higher than that of the single‐unit device. A specific cooling power of 3.6 W g−1 and a maximum COP of 8.3 for the cooling device are produced. The surface temperature of a central processing unit (CPU) cooled by an active EC device is 22.4 K lower than that of the CPU cooled in air. The highly efficient and compact EC cooling device demonstrated here not only leapfrogs the performance of existing solid‐state cooling technologies, but also brings solid state cooling closer to reality for a variety of practical applications that require compact or mechanically flexible refrigeration. [ABSTRACT FROM AUTHOR]

The applications of lithium metal anode are limited by uncontrollable lithium dendrite growth and infinite volume changes during cycling. These fundamental issues are exacerbated at high cycling current densities and capacities. Herein, a mechanically stable and resilient lithium metal host is fabricated by covalently cross‐linking a highly‐conductive and lithiophilic MXene/silver nanowire scaffold through a silylation reaction between MXene nanosheets and polysiloxane. Compared with the control sample (an MXene scaffold assembled by weak van der Waals forces), the covalently cross‐linked MXene scaffold displays excellent mechanical strength and resilience, which is conducive to buffer the large internal stress fluctuations generated during rapid and deep lithium plating‐stripping and guaranteed that the integrated framework structure is maintained during long‐term charging‐discharging cycles. When used in a symmetric cell, the lithium composite anode based on the covalently cross‐linked MXene host affords an unprecedented cyclic lithium plating‐stripping stability of a record‐high 3000 h lifespan at an ultrahigh current density (20 mA cm−2) and areal capacity (10 mAh cm−2). When this composite anode is coupled with a LiNi0.5Co0.2Mn0.3O2 cathode, the full cell delivers an ultrahigh rate of 10 C for up to 1000 cycles, with an average capacity decay of 0.043% per cycle and a stable Coulombic efficiency of 98.7%. [ABSTRACT FROM AUTHOR]

Highlights: Shape memory self-soldering tape used as conductive interconnecting material. Perfect shape and conductivity memory performance and anti-fatigue performance. Reversible strong-to-weak adhesion switched by temperature. With practical interest in the future applications of next-generation electronic devices, it is imperative to develop new conductive interconnecting materials appropriate for modern electronic devices to replace traditional rigid solder tin and silver paste of high melting temperature or corrosive solvent requirements. Herein, we design highly stretchable shape memory self-soldering conductive (SMSC) tape with reversible adhesion switched by temperature, which is composed of silver particles encapsulated by shape memory polymer. SMSC tape has perfect shape and conductivity memory property and anti-fatigue ability even under the strain of 90%. It also exhibits an initial conductivity of 2772 S cm−1 and a maximum tensile strain of ~ 100%. The maximum conductivity could be increased to 5446 S cm−1 by decreasing the strain to 17%. Meanwhile, SMSC tape can easily realize a heating induced reversible strong-to-weak adhesion transition for self-soldering circuit. The combination of stable conductivity, excellent shape memory performance, and temperature-switching reversible adhesion enables SMSC tape to serve two functions of electrode and solder simultaneously. This provides a new way for conductive interconnecting materials to meet requirements of modern electronic devices in the future. [ABSTRACT FROM AUTHOR]

A solar‐thermal water evaporation structure that can continuously generate clean water with high efficiency and good salt rejection ability under sunlight is highly desirable for water desalination, but its realization remains challenging. Here, a hierarchical solar‐absorbing architecture is designed and fabricated, which comprises a 3D MXene microporous skeleton with vertically aligned MXene nanosheets, decorated with vertical arrays of metal–organic framework‐derived 2D carbon nanoplates embedded with cobalt nanoparticles. The rational integration of three categories of photothermal materials enables broadband light absorption, efficient light to heat conversion, low heat loss, rapid water transportation behavior, and much‐improved corrosion and oxidation resistance. Moreover, when assembling with a hydrophobic insulating layer with hydrophilic channel, the MXene‐based solar absorber can exhibit effective inhibition of salt crystallization due to the ability to advect and diffuse concentrated salt back into the water. As a result, when irradiating under one sun, the solar‐vapor conversion efficiency of the MXene‐based hierarchical design can achieve up to ≈93.4%, and can remain over 91% over 100 h to generate clean vapor for stable and continuous water desalination. This strategy opens an avenue for the development of MXene‐based solar absorbers for sustainable solar‐driven desalination. [ABSTRACT FROM AUTHOR]

While stretchable micro‐supercapacitors (MSCs) have been realized, they have suffered from limited areal electrochemical performance, thus greatly restricting their practical electronic application. Herein, a facile strategy of 3D printing and unidirectional freezing of a pseudoplastic nanocomposite gel composed of Ti3C2Tx MXene nanosheets, manganese dioxide nanowire, silver nanowires, and fullerene to construct intrinsically stretchable MSCs with thick and honeycomb‐like porous interdigitated electrodes is introduced. The unique architecture utilizes thick electrodes and a 3D porous conductive scaffold in conjunction with interacting material properties to achieve higher loading of active materials, larger interfacial area, and faster ion transport for significantly improved areal energy and power density. Moreover, the oriented cellular scaffold with fullerene‐induced slippage cell wall structure prompts the printed electrode to withstand large deformations without breaking or exhibiting obvious performance degradation. When imbued with a polymer gel electrolyte, the 3D‐printed MSC achieves an unprecedented areal capacitance of 216.2 mF cm−2 at a scan rate of 10 mV s−1, and remains stable when stretched up to 50% and after 1000 stretch/release cycles. This intrinsically stretchable MSC also exhibits high rate capability and outstanding areal energy density of 19.2 µWh cm−2 and power density of 58.3 mW cm−2, outperforming all reported stretchable MSCs. [ABSTRACT FROM AUTHOR]

The fabrication of fully printable, flexible micro‐supercapacitors (MSCs) with high energy and power density remains a significant technological hurdle. To overcome this grand challenge, the 2D material MXene has garnered significant attention for its application, among others, as a printable electrode material for high performing electrochemical energy storage devices. Herein, a facile and in situ process is proposed to homogeneously anchor hydrous ruthenium oxide (RuO2) nanoparticles on Ti3C2Tx MXene nanosheets. The resulting RuO2@MXene nanosheets can associate with silver nanowires (AgNWs) to serve as a printable electrode with micrometer‐scale resolution for high performing, fully printed MSCs. In this printed nanocomposite electrode, the RuO2 nanoparticles contribute high pseudocapacitance while preventing the MXene nanosheets from restacking, ensuring an effective ion highway for electrolyte ions. The AgNWs coordinate with the RuO2@MXene to guarantee the rheological property of the electrode ink, and provide a highly conductive network architecture for rapid charge transport. As a result, MSCs printed from the nanocomposite inks demonstrate volumetric capacitances of 864.2 F cm−3 at 1 mV s−1, long‐term cycling performance (90% retention after 10 000 cycles), good rate capability (304.0 F cm−3 at 2000 mV s−1), outstanding flexibility, remarkable energy (13.5 mWh cm−3) and power density (48.5 W cm−3). [ABSTRACT FROM AUTHOR]

To promote silver nanowire (AgNW) as a viable commercial alternative for transparent electrodes, it is necessary to further develop industrially scalable, high‐performance yielding and cost‐efficient methods of purifying large quantities of as‐prepared AgNW suspensions. In this work, a facile, effective, and mass scalable purification method that employs a novel dynamic agitation‐induced centrifugal filtration concept to obtain highly purified and printable AgNW solutions. This unique dynamic filtration system, which amalgamates the advantages of membrane filtration, centrifugal filtration and "cross‐flow" filtration, is effective at (1) removing nanoparticles, short nanorods and organic additives from as‐prepared AgNW suspensions without producing aggregation; (2) concentrating purified AgNW suspensions to a desirable concentration; and (3) formulating printable AgNW suspensions with suitable solvents. The resulting purified, polyol‐method synthesized AgNW with a modest aspect ratio of ≈1000 and narrowed length distribution, can be coated into flexible transparent electrodes to yield a transmittance of 99.2% and 95.2% at 230 and 29.6 ohm sq‐1 respectively. These performance metrics are comparable or exceed that of most transparent electrodes made from AgNW with larger aspect ratio (>2000) but purified through conventional purification methods. To maximize the dynamic purification efficiency, a model is also developed to describe and predict this dynamic filtration process. A facile, effective, and mass scalable purification method that employs a novel dynamic agitation‐induced centrifugal filtration concept to obtain highly purified and printable silver nanowire solutions, which can be directly coated into flexible transparent electrodes to yield a transmittance of 99.2% and 95.2% at 230 and 29.6 ohm sq−1, respectively, is introduced. [ABSTRACT FROM AUTHOR]

Abstract: The future of electronics is expected to include healable and wearable devices and systems. To realize this futuristic perspective, several smart conductive materials possessing the characteristics of being healable, flexible, and/or stretchable, are introduced. Silver nanowire (AgNW) healable polymer composite is one of the more promising candidates for this class of material. This ability of AgNW polymer composite to be healable under practical operating conditions is demonstrated. Specifically cracks induced by both mechanical and electrical loading are demonstrated to be healed by thermal treatment. Furthermore, a fatigue test of the AgNW healable conductor is conducted to investigate its mechanical behavior, an important prerequisite for the deployment of new materials. As a proof of concept, a healable touch panel is fabricated to demonstrate its feasibility, laying a stepping stone for future healable electronics. [ABSTRACT FROM AUTHOR]

Abstract: The development of strain sensors with both large strain range (>50%) and high gauge factor (>100) is a grand challenge. High sensitivity requires material to perform considerable structural deformation under tiny strain, whereas high stretchability demands structural connection or morphological integrity for materials upon large deformation, yet both features are hard to be achieved in one thin film. A new 0D–1D–2D ternary nanocomposite–based strain sensor is developed that possesses high sensitivity in broad working strain range (gauge factor 2392.9 at 62%), low hysteresis, good linearity, and long‐term durability. The skin‐mountable strain sensor, fabricated through one‐step screen‐printing process, is made of 1D silver nanowire offering high electrical conductivity, 2D graphene oxide offering brittle layered structure, and 0D fullerene offering lubricity. The fullerene constitutes a critical component that lowers the friction between graphene oxide–based layers and facilitates the sliding between adjacent layers without hurting the brittle nature of the nanocomposite film. When stretching, layer slippage induced by fullerene can accommodate partial applied stress and boost the strain, while cracks originating and propagating in the brittle nanocomposite film ensure large resistance change over the whole working strain range. Such high comprehensive performance renders the strain sensor applicable to full‐spectrum human motion detection. [ABSTRACT FROM AUTHOR]

Abstract: As a next generation of detection technology, terahertz technology is very promising. In this work, a highly efficient terahertz wave absorber based on 3D graphene foam (3DG) is first reported. Excellent terahertz absorption property at frequency ranging from 0.1 to 1.2 THz is obtained owing to faint surface reflection and enormous internal absorption. By precise control of the constant properties for 3DG, the reflection loss (RL) value of 19 dB is acquired and the qualified frequency bandwidth (with RL value over 10 dB) covers 95% of the entire measured bandwidth at normal incidence, which far surpasses most reported materials. More importantly, the terahertz absorption performance of 3DG enhances obviously with increasing the incidence while majority of materials become invalid at oblique incidence, instead. At the incidence of 45°, the maximum RL value increases 50% from 19 to 28.6 dB and the qualified frequency bandwidth covers 100% of the measured bandwidth. After considering all core indicators involving density, qualified bandwidth, and RL values, the specific average terahertz absorption (SATA) property is investigated. The SATA value of 3DG is over 3000 times higher than those of other materials in open literatures. [ABSTRACT FROM AUTHOR]

Vaccination is an effective strategy to fight COVID-19. However, the effectiveness of the vaccine varies among different populations in varying immune effects. Neutralizing antibody (NAb) level is an important indicator to evaluate the protective effect of immune response after vaccination. Lateral flow immunoassay (LFIA) is a rapid, safe and sensitivity detection method, which has great potential in the detection of SARS-CoV-2 NAb. In this study, a fluorescent beads-based lateral flow immunoassay (FBs-LFIA) and a latex beads-based LFIA (LBs-LFIA) using double antigen sandwich (DAS) strategy were established to detect NAbs in the serum of vaccinated people. The limit of detection (LoD) of the FBs-LFIA was 1.13 ng mL− 1 and the LBs-LFIA was 7.11 ng mL− 1. The two LFIAs were no cross-reactive with sera infected by other pathogenic bacteria. Furthermore, the two LFIAs showed a good performance in testing clinical samples. The sensitivity of FBs-LFIA and LBs-LFIA were 97.44% (95%CI: 93.15%–99.18%) and 98.29% (95%CI: 95.84%–99.37%), and the specificity were 98.28% (95%CI: 95.37%–99.45%) and 97.70% (95%CI: 94.82%–99.06%) compared with the conventional virus neutralization test (cVNT), respectively. Notably, the LBs-LFIA was also suitable for whole blood sample, requiring only 3 μL of whole blood, which provided the possibility to detect NAbs at home. To sum up, the two LFIAs based on double antigen sandwich established by us can rapidly, safely, sensitively and accurately detect SARS-CoV-2 NAb in human serum. [Display omitted] • LFIAs based on double antigen sandwich (DAS) have high sensitivity and specificity compared with cVNT. • The FBs-LFIA achieves a sensitivity of 97.44% and specificity of 98.28% in testing clinical serum samples (n = 389). • The LBs-LFIA achieves a sensitivity of 98.29% and a specificity of 97.70% in testing clinical serum samples (n = 554). • The LBs-LFIA can be used to plasma, serum and whole blood samples so it's suitable for home self-test and community hospital. [ABSTRACT FROM AUTHOR]

Here, we describe the development of a triangular silver nanoprism (AgNPR) etching-based plasmonic ELISA for the colorimetric determination of Cr(III) levels in environmental water samples. This involved the creation of a novel signal generation system (substrate reaction solution) for a competitive ELISA in which hydrogen peroxide (HO) is used to etch triangular AgNPRs, inducing a change in color. This is achieved by controlling the HO concentration that remains after degradation by catalase, which is conjugated to the secondary antibody of the ELISA. Because the degree of color change and the shift in the absorption spectrum of the substrate reaction solution are closely correlated with the Cr(III) concentration, this plasmonic ELISA can be used not only for the quantification of Cr(III) concentrations ranging from 3.13 to 50 ng/mL, with a limit of detection (LOD) of 3.13 ng/mL, but also for the visual detection (indicated by a color change from blue to mauve) of Cr(III) with a sensitivity of 6.25 ng/mL by the naked eye. Therefore, the plasmonic ELISA developed in this work represents a new strategy for heavy metal ion detection and has high potential applicability in resource-constrained areas. [ABSTRACT FROM AUTHOR]

The availability and the high-efficiency of the device for cooling the central processing unit provides a unique option for thermal management of microcircuits in the future. Electrocaloric effect, electrostatic actuating, high efficiencies, microelectronics cooling, solid-state cooling Keywords: electrocaloric effect; electrostatic actuating; high efficiencies; microelectronics cooling; solid-state cooling EN electrocaloric effect electrostatic actuating high efficiencies microelectronics cooling solid-state cooling 1 1 1 04/10/21 20210408 NES 210408 In article number 2003771, Rujun Ma and co-workers report a highly efficient double-unit solid-state refrigeration device based on two-layer modified electrocaloric polymer stacks actuated by electrostatic forces. [Extracted from the article]

A novel time-resolved fluorescence blocking lateral flow immunoassay (TRF-BLFIA) was developed for on-site differential diagnosis of pseudorabies virus (PRV)-infected and vaccinated pigs using europium nanoparticles (EuNPs)-labeled virion antigens and high titer PRV gE monoclonal antibodies (PRV gE-mAb). Upon application of a positive serum sample, the specific epitopes of gE protein on the EuNPs-PRV probe were blocked, inhibiting binding to the PRV gE-mAb on the T line, resulting in low or negligible fluorescence signal, whereas when a negative sample was applied, EuNPs-PRV probes would be able to bind the antibody at the T line, leading to high fluorescence signal. Under optimized conditions, TRF-BLFIA provided excellent sensitivity and selectivity. When testing swine clinical samples (n = 356), there was 96.1% agreement between this method and a most widely used commercial gE-ELISA kit. Moreover, our method was rapid (15 min), cost-efficient and easy to operate with simple training, allowing for on-site detection. Thus, TRF-BLFIA could be a practical tool to differentially diagnose PRV-infected and vaccinated pigs. • A time-resolved fluorescence blocking lateral flow immunoassay based on EuNPs-virus antigen probe was first developed. • TRF-BLFIA has excellent clinical applicability in the on-site differential diagnosis of PRV-infected and vaccinated pigs. • The TRF-BLFIA has advantages of simplicity, sensitivity, specificity and rapidity. [ABSTRACT FROM AUTHOR]

Keywords: 3D printing; MXene; stretchable micro-supercapacitor; thick electrode; wearable electronics EN 3D printing MXene stretchable micro-supercapacitor thick electrode wearable electronics 1 1 1 04/16/20 20200414 NES 200414 In article number 1903794, Jiajie Liang and co-workers present a strategy for the 3D-printing and unidirectional freezing of a nanocomposite gel composed of MXene, MnO SB 2 sb nanowires (NWs), AgNWs, and C60 to construct intrinsically stretchable micro-supercapacitors (MSCs) with thick and honeycomb-like porous interdigitated electrodes. The 3D-printed MSC exhibits high areal capacitance of 216.2 mF cm SP -2 sp at 10 mV s SP -1 sp , and remains stable when stretched up to 50%. 3D printing, MXene, stretchable micro-supercapacitor, thick electrode, wearable electronics. [Extracted from the article]

• 3D porous and highly conductive thick electrodes were designed by 3D printing. • 3D-printed thick electrodes were constructed by using nanocomponents-based hybrid ink. • 3D-printed electrodes show both high areal capacity and rate performance. • This strategy represents a simple process for the preparation of thick electrodes. The development of robust performing lithium-ion batteries (LIBs) with high areal capacity is a challenge that persists to date. One commonly used strategy to increase areal capacity is increasing the thickness of the battery electrodes. However, the practical application of these thick electrodes is hindered thanks to the fundamental issues of incomplete electrolyte infiltration, poor mechanical properties, and slow charge and ion transport. Herein, a new method is presented wherein a thick electrode is constructed by 3D printing a highly-conductive and hierarchical network of silver nanowires (AgNWs), graphene and Li 4 Ti 5 O 12 together as a mixed functional ink. The amalgamation of highly conductive AgNW network, interconnected 3D graphene scaffold, and hierarchical porous structure can allow the 3D-printed electrode to demonstrate much improved charge and ion transport, and to alleviate internal stresses during the charging and discharging process even under ultrahigh thickness state. As a result, the LIBs utilizing these thick electrodes have a rate capability of 121 mAh g−1 at 10C, high areal capacities up to 4.74 mAh cm−2, and stable cycling performance (capacity retention of ~95.5% after 100 cycles). These performance metrics provide a route for a new design strategy using thick electrodes for high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal anodes have garnered increasing interest in recent years as its high theoretical capacity and low electrochemical potential promises a myriad of opportunities for various applications. However, one critical issue to overcome is the inhomogeneous deposition of Li+ during the plating and stripping process. This inhomogeneous deposition could result in uncontrollable dendrite growth, further leading to poor coulombic efficiency, shorter lifecycles, and safety concerns due to internal short circuit and thermal runaways. To address these issues, a 3D porous core–shell fiber scaffold is presented, comprising of well‐dispersed SiO2, TiO2, and carbon, as superlithiophilic host materials for lithium anodes. The amorphous SiO2 and TiO2 allow for controllable nucleation and deposition of metal Li inside the porous core–shell fiber even at ultrahigh current densities of 10 mA cm−2. In addition, the interconnected conductive fiber with high porosity enables good electrical conductivity with fast ion transport and excellent mechanical strength to withstand massive Li loading during repeated cycles of stripping and plating. As a result, excellent cycling performance and high rate capability are observed in both symmetric cells and full cells, highlighting the feasibility of the proposed Li anode composite. [ABSTRACT FROM AUTHOR]

Strong terahertz‐response material which exhibits both excellent terahertz shielding and stealth performance is promising in practical applications of terahertz technology. Here, ultralight graphene foam (GF) and multiwalled carbon nanotubes/multiwalled graphene foam (MGF) have been first demonstrated to achieve both superior terahertz shielding and stealth performance due to the dominant absorption loss with negligible reflection. The terahertz shielding effectiveness values of GF and MGF, both 3 mm thick, reach up to 74 and 61 dB. Meanwhile, their average terahertz reflection loss values are achieved up to 23 and 30 dB, respectively, which are the best results in existing broadband terahertz shielding/stealth materials. Importantly, their qualified absorption bandwidths (reflection loss value larger than 10 dB) cover the entire measured frequency band of 0.1–1.6 THz. Furthermore, the quantitative relationships between the terahertz shielding effectiveness, reflection loss, and material parameters are accurately established, which should facilitate the material design for terahertz shielding and stealth. Comprehensively considering the important indicators of density, bandwidth, and intensity, the specific average terahertz shielding coefficient and the specific average terahertz absorption performance are achieved up to 1.1 × 105 and 3.6 × 104 dB cm3 g−1, respectively, which is over thousands of times larger than other kinds of materials reported previously. Graphene‐based composites combining both outstanding terahertz shielding and stealth performance are first demonstrated. The composites present maximum average shielding effectiveness of 74 dB and reflection loss value of 30 dB in the whole measured band due to the dominant absorption loss with negligible reflection (<0.05 dB). Quantitative relationships between terahertz shielding/stealth properties and material parameters are also accurately established. [ABSTRACT FROM AUTHOR]