Search

The development of AI for fluorescent materials design is technologically demanding due to the issue of accurately forecasting fluorescent properties.

Sc2VO5−δ/g-C3N4 heterojunctions (SVCs) with abundant oxygen vacancies (OVs) were synthesized by ultrasonic exfoliation combined with the thermal etching method.

For the composite catalyst, there existed synergetic catalytic effect between the hydroxyl groups and the metal center. All chain growth simultaneously proceeded between the layers or on the surface of HNTs, conducting the in situ ROP.

Sc

Aflatoxin B1 (AFB1) is a group of heterocyclic aromatic hydrocarbon secondary metabolites, which are the most toxic among the known fungal toxins. Therefore, it becomes particularly important to develop sensitive, accurate, rapid and simple methods for the detection of AFB1. In this work, a method of constructing aflatoxin aptasensor with black phosphorus nano sheet loaded with gold nanoparticles as electrode modification material, Ce-metal organic framework (MOF) material as signal label and prism DNA nano structure modified electrode as recognition interface is proposed. The hybridization between prism DNA and primer probe was used to trigger rolling circle amplification (RCA) on the electrode surface, and then the complementary chain modified with Au NPs@Ce-MOF is bound to the amplification chain to provide electrochemical signals. In the range of 0.024-100 ng mL

In this work, an aptasensor based on a portable U-disk electrochemical workstation in combination with a screen-printed electrode (SPE) is demonstrated for the quantitative determination of zearalenone (ZEN). The aptamer is immobilized on Au NPs@Ce-TpBpy COF (Covalent organic frameworks), which is modified on the surface of glassy carbon electrode. ZEN specifically binds to ZEN aptamer, which hinders the electron transfer and decreases the catalytic current of Au NPs@Ce-TpBpy COF for the reduction of hydrogen peroxide, measured by chronoamperometry (

Polycaprolactone (PCL) has been widely applied for its excellent physicochemical properties, but it also has common problems with biopolymers. It is important to investigate energy-efficient polymerization crafts and composite catalytic systems in the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) to prepare high-performance PCL matrix composites. In this study, a composite catalytic system of modified halloysite nanotubes loaded with stannous chloride (APTES-P-h-HNTs-SnCl

Casein was employed for the first time as a green carbon source to prepare water-soluble sulfur and nitrogen co-doped carbon dots (S,N-CDs). The as-synthesized S,N-CDs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy, and fluorescence spectroscopy. Results showed that the as-prepared S,N-CDs had excellent stabilities under various external conditions, such as high ionic strength, different pH levels, UV light irradiation, and long storage duration. More importantly, we found that doxycycline (Dox) could result in an effective fluorescence quenching of S,N-CDs via a static quenching process. Thus, a sensitive and selective sensing system for Dox detection was developed. The linear range was 1.0 × 10−7 M to 1.0 × 10−4 M, and the detection limit was 25 nm. Furthermore, the proposed sensing system successfully detected Dox in raw milk samples. This research will demonstrate the feasibility and potential applications of carbon nanomaterials in food and medical monitoring fields.

A series of UV-excitable α-Na2Ca4(PO4)2SiO4:Eu2+ green phosphors were synthesized by conventional solid-state reactions. The photoluminescence (PL) properties and concentration quenching of the as-prepared phosphors were investigated. All of the phosphors exhibited strong, broad absorption bands in the near-ultraviolet range and gave bright green emission upon excitation with 310 nm light. Eu2+ ions occupy 10-coordinated Ca(3) sites and 6-coordinated Ca(2) sites in α-Na2Ca4(PO4)2SiO4 and therefore generate two emission sub-bands at 497 and 557 nm. The electron–vibrational interaction (EVI) parameters, such as the Huang–Rhys factor, effective phonon energy and zero phonon line position, were calculated. With increasing Eu2+ concentration, the emission peak wavelength red-shifted from 510 to 530 nm, and the color hue can be tuned from green to yellowish green. The concentration quenching mechanism in α-Na2Ca4(PO4)2SiO4:Eu2+ consists of electric multipole–multipole interactions; these are most likely to be dipole–dipole and dipole–quadrupole interactions. These results indicate that α-NCPS:Eu2+ phosphors are promising candidates for application in NUV LEDs.

A simple and cheap method to fabricate a nanocrystal ring pattern was developed by utilization of a microemulsion in this study. The mixture of polystyrene and stabilizer dichloromethane solution that contained nanocrystal aqueous solution, prepared through shaking, was applied to fabricate a reverse microemulsion. After spreading and evaporating the solvent of microemulsion on a glass slide, an ordered honeycomb film was produced, accompanied by the formation of a nanocrystal ring pattern. The nanocrystal pattern could be readily applied for immunoassays and recognition of proteins. The pattern with antibody marked by a green colored nanocrystal specifically bound with antigen labeled by a red colored nanocrystal, leading to the enhancement in red fluorescent ring pattern and decrease in green fluorescent pattern. When the unlabeled antigen was added, the green fluorescent pattern was recovered. In addition, the ring pattern with immunocomplex could selectively recognize antigen and transferrin proteins. This strategy reveals that these patterns have potential applications in biochips, biosensors, imaging analysis and so forth.

Multicolor carbon dots (C-dots) have excellent performance characteristics, high photoluminescence efficiency, ease of fabrication and low toxicity. C-dots have been used in a wide variety of fields including bioimaging, biomedicine, photocatalysis and environmental monitoring. The mass production of multicolor CDs using low-cost, facile methods is an important issue for future industrial applications. In this article, we reported a simple and highly effective way to prepare the multicolor C-dots and use them to detect heavy metal iron ions. Hydrochar acquired from food waste processed with hydrothermal carbonization (HTC) was used as the carbonaceous material for this process. Four colors of C-dots were obtained and included blue, green, yellow and red. These multicolor C-dots could be used as fluorescence probes with unique selectivity to detect the Fe3+ ion. The luminescence response ranged from 1 to 50 μM with a correlation coefficient of 0.9968. This discovery not only shows the high value-added products which can be obtained from food waste but can also lead to new developments in carbonaceous materials which can be used as “green resources”.

Reduced graphene oxide–carbon nanotube (rGO–CNT) hybrids have been synthesized by electrodeposition of GO stabilized CNT using indium tin oxide (ITO) as working electrode, followed by electrochemical reduction of GO–CNT into rGO–CNT on the surface of ITO. The combined characterizations of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses have been used to examine the structure of rGO–CNT hybrids, indicating the successful preparation of hybrids. More importantly, compared with the bare ITO and rGO/ITO electrodes, the rGO–CNT/ITO electrode exhibits excellent sensing performance for electrochemical detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA), leading to a high-performance electrochemical sensor for simultaneous detection of AA, DA and UA. The linear detection ranges of the AA, DA and UA sensors based on rGO–CNT hybrids were estimated to be 10–200 μM, 0.2–8.0 μM and 0.2–16.0 μM, and the detection limits were 5.31 μM, 0.04 μM and 0.17 μM, respectively.

Semen Strychni has anti-tumor, analgesic and anti-inflammatory angiogenesis effects, but the clinical use of Semen Strychni is limited by its potential nephrotoxicity. To investigate Semen Strychni nephrotoxicity and the protective effect of Radix Glycyrrhizae, a stable, parallel and repeatable cell metabolomics strategy was developed in this study. After treatment with Semen Strychni, cell morphology was changed, cell viability was decreased and 8 biochemical indexes were altered. Then the developed cell models were successfully applied for a cell metabolomics study. The Semen Strychni group samples were completely separated from the blank group samples in the score plots of PCA and PLS-DA models. Finally, a total of 10 putative biomarkers and 24 related metabolic pathways were screened. Among the 24 metabolic pathways, the taurine and nitrogen metabolic pathways were believed to have the most importance and significance, respectively. Based on the results, the possible mechanisms of Semen Strychni nephrotoxicity might be cellular component disruption, oxidative damage, metabolic waste accumulation and the disturbance of energy and ion transport systems. Meanwhile, the Radix Glycyrrhizae treatment group showed similar behaviors to the blank group in all assays, indicating the great protective effect of Radix Glycyrrhizae against Semen Strychni nephrotoxicity. This cell metabolomics strategy might contribute to investigating the possible nephrotoxic mechanisms of herb medicines and clinical therapies of protective herbs.

1D Co3O4/α-Fe2O3 core–shell nanofibers were successfully fabricated by a facile and template-free coaxial electrospinning method, and developed for acetone gas detection. Morphology and component characterizations confirm that the as-prepared 1D heterostructures possess a well-defined core–shell structure with Co3O4 in the core and α-Fe2O3 in the shell. The unique 1D core–shell nanostructures, heterojunction effect at the Co3O4/α-Fe2O3 interfaces and the catalysis of Co3O4 endow the Co3O4/α-Fe2O3 core–shell nanofiber-based sensor with an enhanced gas sensing performance in terms of good sensing selectivity, high sensitivity (11.7), rapid response/recovery times (2 s/20 s) and better reproducibility for acetone gas. The gas sensing mechanism is proposed in detail. Overall, the 1D Co3O4/α-Fe2O3 core–shell heterostructure nanofibers synthesized through coaxial electrospinning make a promising and effective acetone sensor.

N-doped few-layer graphene-supported yolk–shell carbon hollow spheres (CHSs/N-G) have been prepared by confined nanospace pyrolysis of GO–polypyrrole (GO–PPy) hybrids obtained by self-assembly of GO and PPy particles. More importantly, such CHSs/N-G exhibits electrochemical catalytic activity for oxidation of L-cysteine, leading to a high performance L-cysteine sensor with detection limit and linear range of 0.2 μM and 2 μM to 80 μM, respectively.

In this paper, in pursuit of developing high-performance graphene-based gas sensors, a novel NO2 gas sensor has been successfully fabricated using ZnO nanoparticles and Au nanoparticles modified reduced graphene oxide (ZnO–rGO–Au) ternary hybrids as sensing materials. The ZnO–rGO–Au hybrids were prepared by deposition of Au nanoparticles on the surface of ZnO–rGO hybrids by the wet chemical method. The combined characterizations of X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive spectroscopy, as well as N2 sorption isotherm indicate the successful preparation of ZnO–rGO–Au hybrids. Most importantly, ZnO–rGO–Au hybrids exhibit good sensing performances for detection of NO2 at relatively low operating temperature (80 °C), such as high response, fast response and recovery rate, and good selectivity. Furthermore, the excellent sensing performances of sensor based on ZnO–rGO–Au hybrids also render it suitable for development of high performance gas sensors.

Naked-eye visible photoswitchable color change is achieved by storage of ultraviolet-induced oxidative energy (photogenerated holes) from TiO2 nanotubular arrays in the Ni(OH)2 layer. The stored oxidative energy can be taken out using reducing agents, which results in a reversible color switch.

A large-scale hierarchical flower-like platinum counter electrode was successfully prepared by a template-free route. The platinum flower is composed of numerous of petal-like platinum nanosheets with a thickness of 25–30 nm, with a significantly enhanced active surface-area and electrochemical performance in DSSCs. The DSSC based on the flower-like Pt counter electrode shows an efficiency of 7.94%, which is enhanced by 19.2% compared to that of a conventional Pt nanoparticle electrode.

A one-dimensional PANI nanofiber supported Pt nanoparticle film is prepared by a two-step electrochemical deposition method. The PANI/Pt film possesses high conductivity, surface area and catalytic activity. A dye-sensitized solar cell based on the PANI/Pt film achieves a high light-to-electric energy conversion efficiency of 7.69%.

Hierarchical ZnO microrods were successfully grown on the upward surface of a Si substrate by a low-temperature hydrothermal method. The morphology and size can be easily controlled by adjusting reaction temperature and reactant concentration. The photocatalytic activities were evaluated by the degradation of Rhodamine B (RB) dye under UV and visible irradiation. The resultant hierarchical ZnO microrods show better photocatalytic activities for the photodegradation of RB than traditional nanoparticles and aligned nanorods.

A macroporous silver network was facilely synthesized using eggshell membrane as template and explored for methanol oxidation reaction, showing a significantly enhanced electrocatalytic ability compared with a traditional silver mirror electrode. The scanning electron microscopy observation showed a hierarchically ordered macroporous silver network because of the Ag+-protein binding. Energy dispersive X-ray spectrum, X-ray diffraction patterns and X-ray photoelectron spectra were used to characterize the resultant macroporous Ag network. The cyclic voltammetric studies at room temperature showed an excellent electrocatalytic activity for a methanol oxidation reaction in an acidic medium. The macroporous silver network was also checked in the electro-oxidation of methanol at high temperatures. A much higher electrocatalytic activity at 250 °C than that at 50 °C made them potential candidates for high-temperature proton exchange membrane fuel cells. The research opens a new insight to design low-cost, highly active and stable catalysts for methanol oxidation. The facile synthesis, excellent properties, alterable supports and low cost allow this material to be used in high-temperature direct methanol fuel cells.