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A sandwich "signal-off" type photoelectrochemical (PEC) immunosensor was fabricated based on a composite heterojunction of tungsten oxide/titanium oxide microspheres (WO3/TiO2) acting as signal amplification platform and carbon microspheres loaded by gold nanoparticles (Cs@Au NPs) utilized as the label for detecting antibody. WO3/TiO2 had excellent photoelectric performance, and the results of Mott-Schottky plots, open-circuit voltage, and electron spin resonance spectroscopy indicated that it belonged to the Z-scheme heterojunction transfer mechanism of photogenerated carriers. To achieve the sensitization of PEC immunosensor, Cs@Au NP–labeled immunocomplex can effectively reduce the photocurrent signal. The PEC immunosensors were fabricated under the optimal conditions of 1:1 WO3/TiO2 (molar ratio), 2.0 mg mL−1 WO3/TiO2, and 1.5 mg mL−1 Cs@Au NPs. Through comparison of the detection results of label-free and sandwich-type PEC immunosensors for nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we found that the sensitivity of the sandwich type was 2.53 times the label-free type, and the limit of detection was 0.006 ng mL−1, i.e., 3.17 times lower than the label-free type. This demonstrates that the developed sandwich-type PEC immunosensor will have a brighter application prospect. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) is rapidly growing and expanding globally, posing threats to ecological safety. Urban light pollution prevention and control are moving toward urban artificial light ecology construction. To clarify the need for light ecology construction, this work analyzes 1690 articles on ALAN and light pollution and 604 on ecological light pollution from 1998 to 2022. The development process and thematic evolution of light pollution research are combed through, the historical inevitability of artificial light ecology construction is excavated, and the ecological risks of light pollution to typical animals are summarized. The results show that international research has advanced to the ecological risk factors of light pollution and the related stress mechanisms, the quantification, prediction, and pre-warning by multiple technical means, and the translation of light pollution research outcomes to prevention and control practices. While Chinese scholars have begun to pay attention to the ecological risks of light pollution, the evaluation indicators and prevention and control measures remain primarily based on human-centered needs. Therefore, a more integrated demand-side framework of light ecology construction that comprehensively considers multiple risk receptors is further constructed. Given the development trend in China, we clarified the consistency of the ecological effect of landscape lighting with landsense ecology and the consistency of light ecological risk prevention and control with the concept of One Health. Ultimately, landsense light ecology is proposed based on the "One Health" concept. This work is expected to provide a reference and inspiration for future construction of urban artificial light ecology. [ABSTRACT FROM AUTHOR]

To overcome the inferior conductivity and ion transfer kinetics of MnO based on materials as lithium-ion batteries anode, microsized carbon coating MnO nanoparticles (HNC@MnO/NC) are designed by hard template and hydrothermal methods combined with the pyrolysis of polydopamine. The coating carbon layer and the presence of oxygen vacancies accelerate the electron transfer and promote the lithium storage performance of HNC@MnO/NC. The internal carbon of the HNC@MnO/NC nanoparticles is used to prevent MnO nanoparticles aggregation during the calcination process; the outer carbon layer not only effectively enhances the conductivity but also avoids the pulverization of MnO nanoparticles, decreasing the undesirable side reactions between the electrode and electrolyte. The HNC@MnO/NC manifests outstanding rate performance at 5 A g−1; its charge capacity and discharge capacity are 338.7 and 342.4mAh g−1. The excellent Li+ storage performance of HNC@MnO/NC indicates that it has potential feasibility in the practical application of good performance Li+ batteries. [ABSTRACT FROM AUTHOR]

Long-cycle stability and high-energy density are big challenges for developing high-performance hybrid supercapacitor (HSC) electrode materials. In this work, molybdenum-doped Co3O4 nanosheets arrays on nickel foam (noted as MoxCo1.5−xO/NF) are successfully prepared via facile one-step electrodeposition followed by annealing for hybrid supercapacitors. The experimental and calculated results indicate that the band gap modification and conductivity enhancement of MoxCo1.5−xO lead to excellent capacitive performance due to the doping of Mo into Co3O4. The as-prepared Mo0.25Co1.25/NF electrode demonstrates a high specific capacity of 128.2 mAh g−1 (923 F g−1) at 1 A g−1 (60% higher than the undoped Co3O4) and superior cycle stability with 95.2% capacity retention after 10,000 cycles at 10 A g−1. The assembled HSC delivers high-energy density of 64.3 Wh kg−1 at the power density of 794.1 W kg−1 and with 87.7% capacity retention after 10,000 cycles. This work can present a new strategy to fabricate the three-dimensional high-performance integrated electrode materials by a facile electrodeposition for heteroatom-doped transition metal oxide for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

The functionalized graphene/montmorillonite (FG/MTT) nanosheet was synthesized through chemical bonding by a simple, green method, which had remarkable dispersion stability in oil and its lubricating performance was evaluated by a four-ball tribometer. The test results showed that FG/MTT had a preeminent lubricant property when the concentration was 0.4 mg/ml. Compared with the bare oil sample, its average friction coefficient (FC) and wear scar diameter (WSD) decreased by 50.4% and 13.2%, respectively. The synergistic effect between FG and MTT was further explored by comparing the lubricant mechanism of the different additives. After synthetically analyzing worn surface by means of scanning electron microscopy and X-ray photoelectron spectroscopy, the lubrication mechanism of the FG/MTT nanocomposite as oil additive was discussed and postulated: the FG/MTT with weak interlayer adhesion was filled between the friction pairs to avoid contact and clinging of some asperities, and the sliding between the layers played a role in lubrication. Furthermore, FG/MTT would react with the surface of the friction pair to form a repair layer composed of Fe2O3, SiC, SiO2, and aluminosilicate, mending the grinding surface and promoting the hardness after friction. [ABSTRACT FROM AUTHOR]

Controlling the morphology of metal–organic frameworks to improve their application in energy storage remains a particular challenge. In this work, hollow porous Co-MOF-74 nanocuboids consisting of nanothorn (< 7 nm) are designed through the linker exchange method for the improved MOFs-based anode of the lithium-ion battery. The Co-MOF-74 inherits the shape of cobalt acetate hydroxide prism and translates into the hollow structure due to the Kirkendall effect. The evolutions of morphology depending on temperature have been investigated further together with the lithium storage performances. Due to the combined merits from the high surface area inheriting from the nanocuboids and the coordination defects originating from the ultrasmall nanothorns, the Co-MOF-74 with optimized morphology exhibits a high reversible capacity and excellent cycle stability (up to 900 mAh g−1 at 1000 mA g−1 after 600 cycles). This work demonstrates an effective way for rational design and synthesis of MOFs-based electrodes for energy storage. [ABSTRACT FROM AUTHOR]

A simple, novel electrochemical sensing platform based on porous g-C3N4 (PCN) and multi-walled carbon nanotubes (MWCNTs) for the sensitive detection of uric acid (UA) has been proposed. The obtained PCN possessed good biocompatibility and large specific surface area with good dispersion, which was beneficial to electrocatalysis. The introduction of MWCNT as the conducting matrix improved the poor conductivity of PCN. Due to synergistic effect, the redox peak currents of UA substantially enhanced at PCN/MWCNT-modified electrode. The oxidation peak current exhibited linear responses to the concentration of UA in the range from 0.2 to 4 μM and 4 to 20 μM, and the limit of detection was calculated as 0.139 μM (signal-to-noise ratio of 3 (S/N = 3)). The sensor based on PCN/MWCNT-modified electrode was also successfully applied in human serums and also showed excellent selectivity, reproducibility, and stability. This work illustrated that the fabricated electrochemical sensor was promising for analytical applications. [ABSTRACT FROM AUTHOR]

The authors describe a nonenzymatic glucose sensor that was obtained by electrochemical deposition and oxidization of metallic nickel on the surface of nitrogen-doped reduced graphene oxide (N-RGO) placed on a glassy carbon electrode (GCE). An analysis of the morphology and chemical structure indicated the composite to possess a well-defined vermicular Ni(OH) nanorods combined with N-RGO. The electrochemical performance of the modified GCE with respect to the detection of glucose in 0.1 M NaOH was investigated by cyclic voltammetry and amperometry. The wrinkle and protuberance of N-RGO for loading of nanostructured Ni(OH) are found to increase electrical conductivity, surface area, electrocatalytical activity and stability. The modified GCE displays a high electrocatalytic activity towards the oxidation of glucose in 0.1 M NaOH solution. The lower detection limit is 0.12 μM at an applied potential of +0.45 V (vs Ag/AgCl) (S/N=3), and the sensitivity is 3214 μA mM cm. The modified GCE possesses long-term stability, good reproducibility and high selectivity over fructose, sucrose and lactose. [ABSTRACT FROM AUTHOR]

We report on the hydrothermal synthesis of boron-doped carbon dots (B-CDs) starting from glucose and boric acid. Doping of the CDs with boron was confirmed by Fourier transform infrared and X-ray photoelectron spectroscopy. The B-CDs have an average diameter of about 4 nm and display blue fluorescence which is dynamically quenched by Fe(III) ions. This finding was exploited to design a method for the determination of Fe(III) in water. The relative fluorescence intensity at 359 nm in the presence and of absence ions is inversely proportional to the concentration of Fe(III) ions, and a Stern-Volmer calibration plot is linear in the concentration range of 0-16 μM, with a 242 nM detection limit. The assay is sensitive, robust and selective. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This review (with 79 references) summarizes the recent work on the development of chemical sensors and biosensors based on the use of composites made from conducting polymers (CPs) and graphene. Owing to the unique electrical, mechanical, optical, chemical and structural properties of CP and graphene, these kinds of composites have generated increasing interest in senor field. In this review, we first discuss methods for preparation of CP/GE composites by chemical, electrochemical, or physical methods including electrostatic interactions. We then cover aspects of the fabrication of modified electrodes and the performance of respective sensors with electrochemical, electronic or optical signal transduction. We then discuss sensors for the determination of inorganic and organic species, gases and vapors. We also review the state of the art in respective biosensors for hydrogen peroxide and glucose, for oligomers (DNA, RNA, and aptamers), for biogenic amines, NAD^+/NADH, cytochromes and the like, and in immunosensors. Finally, the perspective and current challenges of CP/GE composites for use in (bio)sensors are outlooked. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

novel morphology-controlled strategy has been developed to fabricate sulfonated graphene/polyaniline (SGEP) nanocomposites by liquid/liquid interfacial polymerization. Sulfonated graphene (SGE) sheets were synthesized and used as both a macromolecular acid dopant and substrate for the polymerization of polyaniline (PANI), affording the SGEP nanocomposites. The morphology of PANI in the nanocomposites can be controlled to be either nanorods or nanogranules by varying the synthesis conditions. The morphology of SGEP and the shape of PANI can be tuned by adding an additional dopant and varying the amount of SGE used, and this had a significant influence on the electrochemical performance of the nanocomposites as supercapacitor electrode materials. The SGEP nanocomposite with PANI nanorods exhibited a specific capacitance of 763 F/g with a capacity retention of 96% after 100 cycles and good rate properties. Composites obtained with HCl as an additional acid dopant with two different ratios of SGE to PANI showed higher specific capacitances of 793 and 931 F/g, but lower capacity retention after 100 cycles of 77% and 76%, respectively. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The influence of polymerization conditions on the morphology of thin films of poly-(N-methylaniline) (PNMA) was studied. The films were prepared by electropolymerization on gold and platinum electrodes and studied by optical and electron microscopy. It was demonstrated that the film morphology does not depend on the polymerization rate or on the electrode metal. However, it is sensitive to the kind of counter ion of PNMA. The polymers containing acetate or chloride do not form stable films. Polymer films containing phosphate or sulfate display inhomogeneous structures. A formation of sprouts and “nanotubes” was observed for PNMA sulfate. The films formed by PNMA perchlorate are smooth and transparent (glass-like structure). A sublayer of 4-aminothiophenol increases the adhesion of polymers to the gold surface. [ABSTRACT FROM AUTHOR]

The crystal and molecular structure of [Zn(phen)(S2P(OiPr)2)2] (Phen = 1,10-phenanthroline) has been determined by X-ray crystallography. It crystallizes in the Monoclinic system, space group C2/c, with lattice parameters a = 19.315(4), b = 10.438(2), c = 16.567(3)Å, β = 102.89 (3)°, and Z = 4. The complex has C2 symmetry. The coordination geometry of each Zn atom, by two S atoms from two (O,O′-diisopropyldithiophosphato) anions and by two N atoms from phenanthroline ligand, is that of a slightly distorted tetrahedron [Zn—S 2.2914(8)Å Zn—N 2.111(2)Å]. The Zn···S distances to the noncoordinated S atoms are long: 3.5276 Å, which are indicated that there are much weaker interactions between them. [ABSTRACT FROM AUTHOR]