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Since there are several limitations in cancer treatment for traditional chemotherapy, such as side effects, poor prognosis and drug resistance, developing new combined therapy is urgently needed. In this work, a biocompatible, simple and tumor microenvironment-responsive nanotheranostics (PCN-Oxpt/PEG) was built to favor the chemotherapy/ferroptosis/immunomodulation synergism in cancer. This nanotheranostics is constructed by modifying oxaliplatin prodrug and PEG on Fe(III) − porphyrin metal-organic frameworks (PCN(Fe) MOFs). After intravenous injection, the cloak of PEG leads to long circulation, and the Fe(III)-porphyrin MOFs enables dual-model guidance with fluorescence (FL) and magnetic resonance imaging (MRI). Inside the tumor, the intracellular H 2 O 2 would be transferred into hydroxyl radicals (•OH) by iron ions released from MOFs, which could trigger the lethal ferroptosis to cancer cells. Meanwhile, oxaliplatin(II) transformed from the loaded oxaliplatin prodrug would result in the chemotherapy, as well as immunogenic cell death (ICD), and the prodrug strategy could also avoid the occurring of liver damage by the direct administration of oxaliplatin(II). It was noticed that the ferroptosis effect was enhanced by triple-assistance during the combined therapy, as followed: (1) glutathione (GSH) would be consumed in the process of oxaliplatin(II) generation from oxaliplatin prodrug; (2) the increased CD8+ T cells induced by ICD were able to produce interferon-γ (IFN-γ), which could inhibit the transport of cystine by tumor cells, and impair the activation of glutathione peroxidase 4 (GPX4); (3) the amount of H 2 O 2 could be increased by the internalized oxaliplatin and thus further promote the Fenton reaction and ferroptosis. Both in vivo and in vitro results revealed that tumor growing was significantly inhibited by PCN-Oxpt/PEG, taken together, the concomitant of oxaliplatin-mediated chemotherapy and ICD with triple-enhanced ferroptosis offer great prospect in the clinical treatment of cancer. [Display omitted] • A novel nanoplatform (PCN-Oxpt/PEG) was designed for eliminating tumor with combined therapy. • The designed nanoplatform enables dual-model imaging (FL and MRI) to guide antitumor therapy. • Immunosuppressive tumor micro-environment could be remodeled by PCN-Oxpt/PEG, which would enhance ferroptosis efficiently. [ABSTRACT FROM AUTHOR]

Intumescent fire-retardants (IFR) are widely applied in fire protection coatings of steel and wooden structures. The addition of inorganic fillers, such as layered ionic clays, can improve the fireproof performance of IFR coatings. However, a fundamental insight of how these filler materials synergistically interact with the IFR materials remains elusive. In this study, we address this fundamental knowledge gap by systematically investigating the synergy between the IFR fire protection coatings and the CaAlCO 3 -layer double hydroxide (LDH) or montmorillonite (MMT) fillers, which render substantially longer fire resistance (>20 min), reduced specific extinction area (by 54.7 and 44.1 m2 kg−2, respectively), and reduced heat release (by 0.9 and 0.7 MJ m−2, respectively). Combining experimental results and density functional theory calculations, we show for the first time that the superior fireproof performance of the MMT-IFR fire coating originates from the chemical modifications of the char layer by Si-doping. The chemical stabilisation of the silicon- and nitrogen-doped graphene (Si–N-G) structures improves the oxidation resistance of the char layer. Additionally, the formation of the Si–N-G structures with limited lattice deformation stabilised the porous morphology of the char layer, thereby promoting its heat-shielding performance. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the perovskite fluorescent nanocrystals (CsPbBr 3) were successfully synthesized and wrapped with SiO 2 shell, utilized for the assembly of solid-state detection strip capable of conveniently and specifically detection of aflatoxin B 1 (AFB 1). The SiO 2 coating aimed to enhance the stability of CsPbBr 3 nanocrystals. The resulting CsPbBr 3 @SiO 2 material exhibited remarkable fluorescence properties, and further self-assembled onto solid-state plate, generating AFB 1 -specific quenched fluorescence at a specific wavelength of 515 nm. When combined with the capture of AFB 1 by magnetic nanoparticles conjugated with aptamers (MNPs-Apt), it was achieved the good separation and specific detection of AFB 1 toxin in food matrices. The constructed fluorescent solid-state detection strip based on CsPbBr 3 @SiO 2 exhibited good response to AFB 1 toxin within a linear range of 0.1–100 ng mL−1 and an impressive detection limit as low as 0.053 ng mL−1. This presents a new strategy for the rapid screening and convenient detection of highly toxic AFB 1. • Fluorescent CsPbBr 3 nanocrystals coated with SiO 2 to improve the stability. • Self-assembly CsPbBr 3 @SiO 2 -based fluorescent solid-state strip for detecting AFB 1. • Remarkable linear response and sensitivity to AFB 1 with portable solid-state strip. • Good recovery and precision for magnetic aptasensing detection of AFB 1 in foods. [ABSTRACT FROM AUTHOR]

• A method of human key-point coordinate representation based on probability distribution perception. • Addressing issues :key-point representation quantization error, algorithm inconsistency. • This method gives a high level of precision in the experiment. Existing human pose estimation methods have some problems, such as key-point representation quantization error, algorithm inconsistency, and easy-to-introduce unequal quantization error. Addressing these issues, this paper proposes a method of human key-point coordinate representation based on probability distribution perception on a depth convolution neural network. In this method, the perceived probability of the key-point coordinate distribution is extracted by a convolutional neural network, and the cross entropy is formed with the prediction probability distribution as the loss function. Under the constraint of minimizing the Kullback-Leibler (KL) distance between the prediction and the ground truth, the convolution neural network is optimized, and the coordinates of the heat map are finally located. The experimental results show that compared with the traditional method based on a heat map, the proposed method can accelerate the reasoning speed of the model in the COCO training set, and at the same time, it can improve the map by 1.7 [ABSTRACT FROM AUTHOR]

[Display omitted] • An IFR containing acid, carbon, and gas sources was prepared by in-situ calcination. • HRR, EHC, THR, and TOC of fabric with IFR were less than those without IFR. • Carbonization process and fireproof mechanism of IFR on fabric were studied. A novel macromolecular carbon-nitrogen-phosphorous (C-N-P) intumescent flame retardant (IFR) containing acid, carbon, and gas sources was prepared by calcining polyphosphate (APP), pentaerythritol (PER), and melamine (MEL) through the direct heating method. The carbonization and expansion behaviors of IFR were investigated by testing the products of IFR, using nuclear magnetic resonance, X-ray photoelectron spectroscopy, transmission electron microscope, and scanning electron microscopy, at 360 °C, 450 °C, and 600 °C. Conjugated double bonds polymerized the nitrogenous polyaromatic structures as polyphosphate decomposed into phosphoric acid and diphosphate. Noncombustible gases released by MEL increased the internal pressure of the viscoelastic materials to make it expand. At temperatures below 450 °C, MEL promotes the formation of nitrogenous polyaromatic structures in the material, thereby optimizing the IFR char layer structure. The heat release rate, effective heat combustion, total heat release, and total oxygen consume of the IFR coated fabric were less than those of an uncoated fabric by 18%, 5%, 16%, and 13%, respectively, reducing the risk of fire hazard. The foam char formed during the burning of an IFR coated fabric controls the fabric's oxidation process and prevents its shrinking. [ABSTRACT FROM AUTHOR]

• The addition of MgAlCO 3 -LDHs to the IFR coating effectively reduced the TSP and SPR from the cone calorimetry. • Thermal decomposition of MgAlCO3-LDHs could promote and catalyze esterification between APP and PER. • The C-N-P-MgAl coating could improve the thermal insulation performance of the char layer. MgAlCO 3 -layered double hydroxides (MgAlCO 3 -LDHs) were introduced in a waterborne intumescent fire retardant (IFR) with nano-coating containing ammonium polyphosphate (APP), pentaerythritol (PER), and melamine (MEL). The effects of MgAlCO 3 -LDHs were evaluated based on thermogravimetry (TG), differential thermal analysis (DTA), Fourier transform infrared spectroscopic analyses (FT-IR), X-ray power spectroscopy (XPS), scanning electron microscopy (SEM), fire performance test, and cone calorimetry. The 1.8 wt% of MgAlCO 3 -LDHs added to the IFR coating promoted the expansion of the char layer to improve its thermal insulation performance during the fire performance test. The results characterized by TG, DTA, XPS, and FT-IR revealed that MgAlCO 3 -LDHs enhanced the residual weight, the thermal stability and the oxidation resistance of the IFR coating. There was statistical evidence that the heat-shielding performance was reinforced by adding an appropriate amount of MgAlCO 3 -LDHs to the IFR coating to form uniform and compact foams in the char layer by using the digital image to process SEM images. The cone calorimetry revealed that a 46% reduction in total smoke production (or total smoke release) and a 25% decrease in the smoke production ratio were achieved in the coating with added MgAlCO 3 -LDHs compared with that without. It can be concluded that the addition of MgAlCO 3 -LDHs to IFR coating actively interacts with APP, PER, and MEL, thus improving the fire retardant properties of the coating. [ABSTRACT FROM AUTHOR]

A water-based fire resistive nano-coating was prepared via adding CaAlCO 3 -layered double hydroxides (CaAlCO 3 -LDHs) as an inorganic filler to intumescent fire retardant coating. The influence of CaAlCO 3 -LDHs on the coatings properties was investigated by thermogravimetry (TG), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), cone calorimeter (CONE) and fire performance test. The results showed that CaAlCO 3 -LDHs could improve the quality of the residual char layer, increase the degree of the cross-linking and the carbon accumulation, and enhance the oxidation resistance of the char layer. The addition of 5 mass% CaAlCO 3 -LDHs to the coating could reduce the fire hazards of the coating itself, lower the rate of flame propagation and thermal degradation, and improve the char structure and fire resistance of the coating, which was attributed to the synergistic effect of CaAlCO 3 -LDHs and the intumescent fire retardant (APP/PER/MEL). [ABSTRACT FROM AUTHOR]

Abstract: An efficient method for the synthesis of α-aminonitriles via one-pot three-component condensation of ketones, amines and potassium hexacyanoferrate(II) using benzoyl chloride as a promoter and PEG-400 as a reaction medium was described. This protocol has the features of use of eco-friendly cyanide source, green reaction medium, high yield, and simple work-up procedure. [Copyright &y& Elsevier]

A unit cell-based design support system (UCBDSS) for composite structural design is introduced. A unit cell is defined as the smallest representative volumetric element to carry the information of composite constituent materials, heterogeneous structures, homogenized mechanical properties, and appropriate manufacturing processes. The database of various composite unit cells is organized to form a unit cell library (UCL). The UCBDSS can intelligently use the information from the UCL to simplify and automate the composite design process, to increase the design efficiency, and to facilitate the tailored composite structure design. The framework of the UCBDSS, its modules, the development of the UCL, the blackboard architecture for design control, and the UCBDSS working environment for Internet-based design are presented. [Copyright &y& Elsevier]

Development of effective methods for quantificationally characterizing the thermal resistance of the intumescent char layer of fired fire-retardant coating is of interest in many academic researches and industrial applications. In this work, a novel approach is proposed to calculate the thermal resistance of the intumescent char layer produced after the ultra-thin fire-retardant coating exposed to fire. A correlation was established based on the relative thermal resistance of the char layer to that of steel plate and the surface temperature at the back of the coated steel plate under steady-state heat transfer. The thermal resistance of the steel plate was obtained about 0.009 K·m2·W−1 by calculating the heat flux based on the radiation heat exchange involving three-surface enclosure model (flame, steel, and wall). The thermal resistances of the char layers without and with the layered double hydroxide (LDH) were 0.011 K·m2·W−1 and 0.013 K·m2·W−1, respectively. The results show that the external roughness and internal honeycomb structure can increase both the conductivity and the convective thermal resistances of the char layer to protect the steel structures. The porosity of the char layer is between 0.15 and 0.18, and its thermal conductivity is between 0.4 and 0.8 W·m−1·K−1 in the process of fire. Unlabelled Image • A novel method is proposed to calculate thermal resistance of intumescent char layer. • Thermal resistance is used to evaluate heat-shielding performance of char layer. • LDH improves external roughness and internal honeycomb structure of char layer. • Porosity of char layers is obtained to be 0.15–0.18 via SEM images processing. • Thermal conductivity of char layers is 0.4–0.8 W·m−1·K−1 in the process fire. [ABSTRACT FROM AUTHOR]

• Addition of MgAlCO 3 -LDHs and CaAlCO 3 -LDHs improved thermal insulation of IFR coating. • Metal ions from LDHs were chelated with carbon materials to form 3D reticular char. • LDHs can delay oxidation and improve degradation performance of char layers. MgAlCO 3 -layered double hydroxides (LDHs) and CaAlCO 3 -LDHs were respectively added as a synergistic agent to intumescent fire retardant (IFR) coatings. The 2.4 wt% of MgAlCO 3 -LDHs and the 6.7 wt% of CaAlCO 3 -LDHs were found to possess the best thermal insulation according to the fire performance tests. Further characterization by a cone calorimeter shows that the MgAlCO 3 -LDHs are superior to decreasing the specific extinction area of IFR coating, and the CaAlCO 3 -LDHs are advantageous in some other properties such as heat release rate, effective heat combustion and total heat release. Moreover, the X-ray diffraction (XRD) results infer that the flame retardant of char layer is primarily dependent on the amorphous structure formed after exposure to fire, the X-ray photoelectron spectroscopy (XPS) measurements of O 1s , C 1s , P 2p and N 1s reveal that the LDHs fillers suppress the oxidation of the IFR coating, and the Fourier transform infrared spectroscopy (FTIR) tests demonstrate that the LDHs protect the bridge frame structures. It is concluded that the LDHs can prevent the degradation and improve the thermal insulation of IFR coatings. [ABSTRACT FROM AUTHOR]

• An analysis method for SEM images of intumescent fire retardant char layers is proposed. • Foams in an intumescent fire retardant char layer are characterized quantificationally. • Appropriate addition of CaAlCO 3 -LDHs makes the char layer compact and uniform. • Unsatisfactory result image after color transformation is returned to object segmentation. A new characterization method is proposed to investigate the microscopic morphology of intumescent fire retardant (IFR) char layer observed under a scanning electron microscope (SEM). The method consists of object segmentation extracting the object, color transformation improving the recognition of subtle details, and statistical analysis obtaining the features (area, average, and standard deviation) of the object in the SEM images. There is a descending trend in the standard deviation of the foams with the increase of CaAlCO 3 -LDHs (layered double hydroxides) added to the coatings. Specifically, the number of the foams in the IFR coating with 5 wt% of CaAlCO 3 -LDHs addition is increased from 102 (that of the char layer without CaAlCO 3 -LDHs) to 123. Meanwhile, the standard deviation of the foams in the char layer is decreased from 6383.6 to 4304.5, demonstrating that an appropriate addition of CaAlCO 3 -LDHs can improve the foam quality of the IFR coating by making it more compact and uniform, and enhance the thermal insulation of the char layer covered on the substrate surface. [ABSTRACT FROM AUTHOR]

Robust antifogging films have significant potential for a wide range of applications on the surfaces of transparent materials. Nevertheless, currently either their preparation methods are complex or their mechanical properties such as hardness, wear, scrub and water resistance are yet to be improved before they can be applied in practical applications. In this work, we have developed a facile room temperature approach to fabricating free-standing films of excellent antifogging properties and mechanical robustness. Glutaraldehyde (GA) was used to cross-link polyvinyl alcohol (PVA) and ultraviolet (UV) light was applied to initiate polymerization of poly (ethylene glycol) diacrylate (PEGDA), leading to robust interpenetrating networks (IPN). The films also had excellent mechanical properties with pencil hardness up to 8H, Taber wear-resistance up to 10,000 cycles, and sponge scrub resistance up to 300 cycles. The tensile strength and tearing strength of films reached as high as 100 MPa and 700 kN/m, respectively, much higher than those of free-standing films reported so far. This approach may hold great potential for broad application on various substrates, particularly those with low glass transition temperatures (e.g., transparent plastic films). It may expand the possibilities for future applications of free-standing antifogging films for screens, optical lenses and so on. [Display omitted] • A facile approach to fabricating free-standing films of excellent antifogging properties and mechanical robustness. • Pencil hardness up to 8H, Taber wear-resistance up to 10,000 cycles, and sponge scrub resistance up to 300 cycles. • The tensile strength and tearing strength of films reached as high as 100 MPa and 700 kN/m, respectively. • The current work is the first report of freestanding interpenetrating films with excellent mechanical robustness. [ABSTRACT FROM AUTHOR]

• A smartphone-assisted fluorescence-colorimetric immunosensing platform was proposed. • NH 2 -UiO-66@PtNPs was exploited to construct a fluorescence-colorimetric signal probe. • The multi-mode immunosensing microarray showed satisfactory results of AMD detection. • The efficient, visual and portable method showed great potential in food analysis. Amantadine (AMD) is an antiviral drug used to treat animal-based infectious diseases such as avian influenza. However, its illegal use in animal-derived food industries endangers human health. Therefore, an efficient, portable, and visual sensor to detect AMD in food is crucial for ensuring food safety. A multifunctional nanocomposite NH 2 -UiO-66@PtNPs was exploited to design a smartphone-assisted fluorescence-colorimetric immunosensing microarray for multidimensional detection of AMD in animal-derived foods. Platinum nanoparticles (NPs) were immobilized on a Zr-based metal–organic framework (NH 2 -UiO-66). Pt NPs exhibited peroxidase-like activity, whereas NH 2 -UiO-66 stabilized Pt NPs and improved the colorimetric signal of the sensor. Moreover, the fluorescence ligand NH 2 -BDC in NH 2 -UiO-66 was released via alkaline hydrolysis, amplifying the fluorescence signal and improving detection sensitivity. The smartphone-assisted color recognition system accurately identified the color changes of the microarray. The immunocompetitive reaction of AMD and the antibody (Ab) in the microarray NH 2 -UiO-66@PtNPs@Ab 2 allowed the quantitative and visual detection of AMD in a wide concentration range (0.1–1000 ng/mL) with high sensitivity [limit of detection = 0.0022 ng/mL (fluorescence), 0.069 ng/mL (colorimetric), and 0.68 ng/mL (smartphone)]. This detection strategy was verified in AMD-spiked food samples with satisfactory recoveries (82.0–103.0%) and stability (RSD: ≤7.1%, n = 3), showing its great potential for visual screening and portable detection of other food contaminants. [ABSTRACT FROM AUTHOR]

The therapeutic application of chemodynamic therapy (CDT) is severely limited by the insufficient intracellular H 2 O 2 and acidity in tumor. Herein, an acid-sensitive nanoplatform (ZIF67-ICG/TAM@GOx) to promote H 2 O 2 and acidity enhancement through intracellular cyclic amplification for enhanced CDT is rationally designed. Notably, the acidic conditions of the tumor microenvironment (TME) can turn on the switch of the nanoplatform, setting free the loaded tamoxifen (TAM) and indocyanine green (ICG). The mitochondrial respiration inhibitor TAM and the superoxide dismutase-mimicking ZIF67 synergistically lead to an increase in the content of O 2 and H 2 O 2 , accelerating the depletion of β- d -glucose by GOx to generate gluconate and H 2 O 2. The gluconate in turn boosts the acidity to facilitate the collapse of nanoparticles, further significantly promoting the accumulation of intracellular H 2 O 2 through a positive circulation. Consequently, the amplificated endogenous H 2 O 2 is catalyzed by Co2+ to liberate hydroxyl radicals (•OH). Besides, ICG-mediated photothermal therapy (PTT) and GOx-induced starvation therapy along with CDT realize the synergistic cancer treatment. Importantly, in vitro and in vivo experiments verified that the nanoplatform performed superior specificity and excellent therapeutic responses. The smart nanoplatform overcomes H 2 O 2 and acidity deficiency simultaneously for intensive CDT, providing new prospects for the development of biocompatible cancer synergistic therapy strategies. In the tumor microenvironment, the released TAM, GOx and ZIF67 synergistically lead to a positive circulation for self-amplified CDT, cooperating with PTT and starvation to realize the synergistic cancer treatment. [Display omitted] • An acidic sensitive nanoplatform (ZIF67-ICG/TAM@GOx) is constructed for specific tumor therapy. • The combination of TAM, ZIF67 and GOx enabled positive circulation to accumulate H 2 O 2 and acidity for boosting CDT. • The disruption of H 2 O 2 homeostasis made the approach of "expanding source and cost-saving" for the increase of H 2 O 2. • The self-amplified CDT along with PTT, GOx-induced starvation realized a novel synergistic cancer therapy strategy. [ABSTRACT FROM AUTHOR]

Abstract: In the current work, CuO nanoparticles were synthesized in a facile way, and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetry. Using these CuO nanoparticles, CuO functionalized QCM resonators were fabricated and explored for HCN sensing. The sensing properties were studied by a sensor characterization system coupled with a mass spectrometer. The sensor response to HCN (+347Hz) was found to be in an opposite direction as compared with other common volatile substances (ether: −1230Hz; water: −1815Hz; n-hexane: −2100Hz; benzene: −3410Hz; acetic acid: −4840Hz; ethanol: −6270Hz), offering excellent selectivity for HCN detection. In addition, the sensitivity (15.1Hz/μg) was very high, and the response (30s) and recovery (750s) were very fast. A sensing mechanism was proposed based on experimental results, in which a surface redox reaction occurs between CuO and Cu2O on the nanoparticle reversibly upon contact with HCN and air, respectively. The current results would provide an exciting alternative to fast, sensitive and selective detection of trace HCN, which would be of particular benefit in the area of public security and environmental applications. [Copyright &y& Elsevier]

CO 2 capture and utilisation (CCU) is a promising strategy to effectively mitigate the adverse greenhouse effects caused by CO 2 emissions at an industrial scale. Through a process intensification strategy known as integrated CO 2 capture and utilisation (ICCU), CO 2 capture and catalytic CO 2 conversion can be achieved in a single process with the use of dual function materials (DFMs), which are both CO 2 sorbents and CO 2 conversion catalysts. Given the significantly different operating conditions of ICCU from conventional catalytic CO 2 hydrogenation, the catalytic mechanism of DFMs, especially during CO 2 hydrogenation, needs to be thoroughly investigated. In this study, the relationship between the nature of the Ni/carbonate interfaces and the performance of Ni-based DFMs over ICCU cycles is systematically investigated. A series of Ni/alkaline earth carbonate DFMs were synthesised with varying Ca:Mg ratios to simulate different metal-carbonate model interfaces. At 400 °C, CH 4 formation with nearly 100% CH 4 selectivity was achieved on Ni/CaCO 3 over 15 ICCU cycles. In general, Ni/CaCO 3 interfaces correspond to higher CO 2 conversion and higher CH 4 selectivity than Ni/MgCO 3 interfaces. Such trend may be attributed to the higher surface basicity of CaO and the higher thermal stability of CaCO 3. As a consequence, the hydrogenation of the Ni/CaCO 3 interface proceed via the formate pathway, in which carbonates are consecutively converted to surface formates, methoxyl, methyl species and eventually desorb as methane. This reaction model is applicable to the hydrogenation of both surface carbonate and bulk carbonates, although the former proceeds with much faster kinetics. On the weakly alkaline Ni/MgCO 3 interface, MgCO 3 preferentially decomposes to form gaseous CO 2 , which is subsequently hydrogenated via the reverse-water-gas-shift pathway, with CO as the key reaction intermediate. Interestingly, in situ infrared spectroscopy shows similar surface significant species during the direct hydrogenation of DFMs and during the conventional catalytic hydrogenation of molecular CO 2 , suggesting that the catalytic mechanisms during the two operating regimes are highly correlated. [Display omitted] • Novel Ni/carbonate dual function materials for CO 2 capture and hydrogenation. • Different hydrogenation behaviour and pathway on Ni/CaCO 3 and Ni/MgCO 3 interfaces. • Two reaction regimes proposed during hydrogenation of Ni/CaCO 3. • Suitable basic sites and metal-support interaction favours the hydrogenation. • Correlation between ICCU cycles and those of conventional CO 2 hydrogenation. [ABSTRACT FROM AUTHOR]

Amyloid-β oligomers (AβO) have been identified as core biomarkers for early diagnosis of Alzheimer's disease (AD). For the first time, a "turn-on" unlabeled colorimetric aptasensor based on aptamer-polythymine (polyT)-polyadenine (polyA)-gold nanoparticles (pA-pT-apt@AuNPs) was developed for highly sensitive and specific detection of amyloid-β 1-40 oligomers (Aβ40-O). In this system, polyA sequence could preferentially anchor onto AuNPs surface as well as reduce the non-specific adsorption, and the aptamer could form upright conformation for the specific recognition of Aβ40-O. The aggregation of pA-pT-apt@AuNPs was induced by MgCl 2. However, the addition of Aβ40-O enabled the aptamer fold adaptively upon recognition and aptamer-Aβ40-O complex formed surrounding AuNPs, effectively stabilizing pA-pT-apt@AuNPs against salt-induced aggregation, therefore the color of pA-pT-apt@AuNPs solution still retained red. Based on this principle, the proposed aptasensor exhibited high sensitivity with the limit of detection of 3.03 nM and a linear detectable range from 10.00 nM to 100.0 nM. The superb sensitivity was achieved via the optimization of the length of polyA and polyT spacer. This pA-pT-apt@AuNPs based colorimetric aptasensor provides a rapid, cost-effective, highly sensitive detection method for Aβ40-O, which is valuable for the early diagnosis of AD. [Display omitted] • A pA-pT-apt@AuNPs-based colorimetric aptasensor was developed for Aβ40-O detection. • The proposed aptasensor avoided the non-specific adsorption on AuNPs surface. • The upright conformation of aptamers benefited the specific recognition of Aβ40-O. • Superb sensitivity was achieved with the limit of detection of 3.03 nM. • The aptasensor is simple, rapid (response time of 1.5 h) and cost-effective. [ABSTRACT FROM AUTHOR]

Copper oxide nanoparticles were prepared by the solvothermal method, and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption measurements. The as-prepared CuO nanoparticles functionalized QCM resonators were fabricated and explored for HCN sensing under varied humidity conditions. When the humidity of air containing HCN is the same as that of environmental air, a characteristic positive frequency shift of CuO nanoparticles functionalized QCM resonator is always observed towards HCN because of a reversible surface redox reaction between CuO and HCN. The sensitivity of CuO nanoparticles functionalized QCM resonators increases with increase of relative humidity in the range of 9-51%. These results provide an important guidance for further developing HCN gas sensors towards practical applications. [ABSTRACT FROM AUTHOR]

Abstract: A novel biosensor is developed based on immobilization of proteins on nanoflake-like SnS2 modified glass carbon electrode (GCE). With glucose oxidase (GOD) as a model, direct electrochemistry of the GOD/nanoflake-like SnS2 is studied. The prepared SnS2 has large surface area and can offer favorable microenvironment for facilitating the electron transfer between protein and electrode surface. The properties of GOD/SnS2 are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV), respectively. The immobilized enzyme on nanoflake-like SnS2 retains its native structure and bioactivity and exhibits a surface-controlled, reversible two-proton and two-electron transfer reaction with the apparent electron transfer rate constant (k s) of 3.68s−1. The proposed biosensor shows fast amperometric response (8s) to glucose with a wide linear range from 2.5×10−5 M to 1.1×10−3 M, a low detection limit of 1.0×10−5 M at signal-to-noise of 3 and good sensitivity (7.6±0.5mAM−1 cm−2). The resulting biosensor has acceptable operational stability, good reproducibility and excellent selectivity and can be successfully applied in the reagentless glucose sensing at −0.45V. It should be worthwhile noting that it opens a new avenue for fabricating excellent electrochemical biosensor. [Copyright &y& Elsevier]

Abstract: An energetic coordination compound [Cd(DAT)6](ClO4)2 has been synthesized by using 1,5-diaminotetrazole (DAT) as ligand and its structure has been characterized by applying X-ray single crystal diffraction, elemental analysis and FT-IR spectroscopy. The central cadmium(II) cation is coordinated by six N atoms from six DAT molecules to form a six-coordinated and distorted octahedral structure. Di-dimension layer structure was formed and the layers were linked together by the extensive intermolecular hydrogen bonds between DAT ligands and ClO4 − anions. Thermal decomposition mechanism of the title compound was predicted based on DSC, TG-DTG and FT-IR analyses results. The kinetic parameters of the first exothermic process of the title compound were studied by applying the Kissinger''s and Ozawa–Doyle''s methods. Sensitivity tests reveal that the title compound has sensitive nature. [Copyright &y& Elsevier]

A rhodamine B-based sensor (RS) was designed and synthesized by a combination of the spirolacton rhodamine B (fluorophore) and multidentate chelates (ionophore) with high affinity towards Hg2+. In the presence of Hg2+, the resulting red-orange fluorescence (under UV light) and naked eye red color of RS are supposed to be used for quantitative and qualitative measurement of Hg2+. Further fluorescent titration and analysis demonstrate that RS can selectively detect Hg2+ within 1 s with a low limit of detection (LOD) of 16 nM in acetonitrile media, meanwhile, the association constant (K a) was calculated to be 0.32 × 105 M−1. More importantly, the resultant complex (RSHg) of RS and Hg2+ has also been successfully applied to detect limited water content in acetonitrile solution. Unlabelled Image • A rhodamine-based sensor (RS) can be applied in detection of mercury (II) and water content in acetonitrile media. • RS displays a high selectivity towards mercury (II) and can react immediately with mercury (II) within 1 s. • RS can quantitatively determine mercury (II) with a low limit of detection (LOD) of 16 nM. [ABSTRACT FROM AUTHOR]