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Trace analyte detection in a complex environment such as in seawater is usually challenging for classic redox-based electrochemical sensors since the matrix effect of high salinity and various interfering species with similar redox properties can generate false positive/negative signals, thus impacting the sensitivity and specificity of the sensors. In this work, unlike redox-based approaches, we propose a novel sensing mode that relies on dual-modulated interfacial energy barriers of heterojunctions. By constructing the hierarchical structure of Ni/TiO

1,2-Diaza-4-phospholide alkali metal complexes showed stair-shaped chain structures, where P(iii) could be oxidized by S8 and Se. The 1H DOSY NMR spectroscopy analysis suggested that they dissociated into monomers in the solution.

A sensitive procedure was developed for trace Cr determination by ICP MS with a DDTC enhanced nebulized film dielectric barrier discharge (NFDBD) vapor generation sampling system.

Analyte-triggered nanoparticle (NP) assemblies in bulk colloidal suspension have been extensively utilized in various optical sensors. Nevertheless, the assembling process is still limited by the slow diffusion dynamics of NPs and the low concentration of analytes in trace detections, which hinders further improvement of the sensitivity and repeatability of the sensors. In this work, by functionalizing the gold NPs with specific ligands, we constructed a dual-mode optical sensing platform for multianalytes based on the plasmonic NP array at the liquid-liquid interface. Through emulsification, the NP diffusion kinetics are boosted for several orders, and the NPs are condensed from the bulk aqueous phase to the liquid-liquid interface as a plasmonic array. The as-formed metasurface generates major reflectance and surface-enhanced Raman scattering changes in response to analytes, providing two optical sensing modes. As prototypes, cysteine and glucose are selected as the target molecules, achieving the limit of detection as 193 ± 2 and 297 ± 12 pM, respectively.

The analyte-induced aggregation of plasmonic nanoparticles (NPs) in the bulk solution have been widely employed in optical sensors. However, in trace detection, the slow diffusion kinetics of NPs and the ultralow concentration of analytes significantly limit the binding opportunity of the analytes, thus impose penalties on the sensitivity, reproducibility and response time of the sensors. Herein, we propose a novel sensing method with two working modes that based on the construction/destruction of NP arrays at the liquid-liquid interface (LLI). For the turning-on mode, the emulsion state of the two immiscible liquid phases and specific binding between Cd

Solar steam generation has been considered one of the most promising approaches for dealing with the energy and freshwater resource crises in recent years. However, achieving high efficiency in photo-thermal conversion remains a considerable challenge. Here, a series of hierarchical Ti3C2/MoS2 nanocomposites were designed for steam generation by a hydrothermal method. When the mass fraction of MoS2 reached 65 wt% (TM-3), the Ti3C2/MoS2 nanocomposite presented a strong broad-band light absorption of 92.4% from the UV to NIR region because of the accordion-like layered structure. The evaporation rate and solar-thermal conversion efficiency of the TM-3 with as-fabricated evaporator could reach 1.36 kg·m−2·h−1 and 87.2% under 1 kW/m2, due to the excellent light absorption ability of TM-3 and the low thermal energy loss (8.8%) of the evaporator. Meanwhile, TM-3 permits the evaporator to have remarkable cycle stability because of its hydrophobic properties. Moreover, TM-3 showed excellent seawater desalination and wastewater treatment abilities. Thus, the excellent light absorption ability, photo-thermal conversion efficiency, and stability of the overall system suggested that these nanocomposites show great potential applications in synergetic solar desalination and sewage treatment.

Copper ions (Cu2+) pollution in the water environment poses a great threat to the health function of life-sustaining metabolic activities. However, the current detection methods need relatively expensive instruments, complex operation procedures and long time, so a facile and direct detection method is desired to be developed. In this work, the Ni-based composite wires with p-n junction (the Ni/NiO/ZnO/Chitosan wire) and Schottky junction (the Ni/NiO/Au/Chitosan wire) were fabricated, and the barrier driven electrochemical sensing mechanism was studied. The direct and facile detection of Cu2+ was achieved with a wide linear range (0–6000 nM) and a low LOD (0.81 nM). The excellent stability and recovery in real water samples made the Ni-based composite wires a promising candidate for the practical application. The interfacial barriers of semiconductor can be used as a special sensing factor to develop novel sensors.

The accurate electrochemical detection of dopamine (DA) is hard to achieve due to the serious interference of a substance with similar redox properties. The 3D Ni/NiO/MoS2/rGO hierarchical foam was prepared for use as an electrochemical electrode for biosensing, and the highly sensitive detection of DA with excellent selectivity was achieved. The enhanced performance resulted from the synergistic effect of Schottky interfaces between MoS2 and rGO according to the contrast test (Fig. 4a, b and Fig. S2, ESI†). It was found that the presence of a Schottky barrier could be used for adjusting electrochemical response by inducing the change of barrier height, which was employed for enhancing the sensitivity to DA and depressing the interference. It is a general strategy to adjust electrochemical response by employing a Schottky barrier to achieve anti-interference and can be expanded to other detection methods.

A novel type of electrochemical sensor for detection of phosphate in water environment was developed by combining the interfacial barrier of p–n junction with the adsorption of phosphate. The electrochemical response was produced by the induced change of the barrier height, which was only caused by the specific adsorption of phosphate. Two linear concentration ranges (0–0.045 mg L−1 and 0.045–0.090 mg L−1) with two sensitivities (4.98 μA (μg L−1)−1 and 1.28 μA (μg L−1)−1) were found. The good performance made the sensor meet the requirements of the World Health Organization for drinking water (1 mg L−1 of phosphate). It is an approach to develop electrochemical sensors by employing the interfacial barrier effects on electrochemistry.

The Ni foam decorated with ZnO/BiOI core-shell p-n junction nanorods was prepared and employed as an enzyme loading matrix to detect glucose. The detection potential was decreased significantly (0.3 V) and the sensitivity was enhanced largely (115.2 μA mM−1 cm−2). The metal-semiconductor foam can afford the porous surface for loading enzymes and achieving the multiple catalysis. More important, the built-in electric field and electron well in the p-n junction interface provide the driving force for electron transport. It was an effective strategy to enhance the biosensing performance by the rational design of p-n junction.

Bismuth(III) oxidation of 3,5-di-substituted-1,2,4-triazolato anions afforded a paddlewheel 1,2,4-triazolato dibismuth complex [L2(Bi–Bi)L2] (L = η1,η1-3,5-R2tz, R = Ph (3), iPr (4)) with very short Bi(II)–Bi(II) bonds (2.8650(4)−2.8721(3) A). The reaction involved the intermediates of the organobismuth radical [Bi(R2tz)2]˙ and neutral N-1,2,4-triazolyl radical [3,5-R2tz]˙. The dimerization of the former produced the corresponding dibismuth complex while the latter was trapped by using spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) to give the radical adduct of {(3,5-R2tz)(DMPO)}˙ which was unambiguously evidenced by EPR analysis.

Hg2+ pollution poses a major threat to human health and the ecological environment, but there is still a lack of direct and sensitive Hg2+ detection technology. In this study, Cu/CuO/ZnO wires were prepared by alkaline oxidation and hydrothermal methods. Polypyrrole (PPy) was covered on the surface of the material by electrochemical polymerization. Using the principle of electrochemical signal response driven by p-n junction barrier, the material was used for the direct electrochemical detection of Hg2+ and was tested by differential pulse voltammetry. The composite has a good linear relationship in the Hg2+ concentration range of 200–1600 nmol/L, and has ultra-high sensitivity (1,010.82 μA∙L/(nmol∙cm2)) and ultra-low detection limit (2.1 pmol/L). The new sensing mode based on the interface barrier eliminates the interference of other ions. The recovery rate of Hg2+ in tap water, river water and sea water is 97.3%–105.0%, and the RSD is 1.8%–5.6%. This method using p-n junction barrier can be extended to the development and research of other sensors for detecting heavy metal ions.

We proposed a new method for regulating the electrochemical signal by using Schottky barrier. The results show that the height of Schottky barrier can be altered by adsorbing charged substance to control the enhancement and attenuation of electrochemical signal. The Schottky interface formed by MoS2 and CQDs (carbon quantum dots) can achieve the selective detection of dopamine and overcome the distraction of ascorbic acid and uric acid with similar redox signal. The combination of Schottky barrier and electrochemical detection enhance the sensitivity and selectivity of electrochemical sensor significantly. It is a new strategy for improving electrochemical detection by introducing Schottky barrier into electrochemical process.

The multi-walled carbon nanotubes decorated with Co3O4 nanoparticles (Co3O4/MWCNTs) were successfully prepared by the hydrothermal method. A facile and practical electrochemical sensor based on Co3O4/MWCNTs was established for simultaneous detection of hydroquinone (HQ) and catechol (CC) by differential pulse voltammetry (DPV). The defined and separated oxidation peaks of a mixture of HQ and CC were obtained at pH 8.0, owing to the catalytic stability of Co3O4 in alkaline conditions as well as the high conductivity and excellent adsorption of MWCNTs. The proposed sensor exhibited the wide linear range from 10 to 800 μM (HQ) and 10–700 μM (CC), as well as the low detection limit of 5.6 μM (HQ) and 8.5 μM (CC). Meaningfully, in local seawater sample testing, the explored sensing platform achieved an excellent recovery for the simultaneous detection of CC (97.5–104.2%) and HQ (96.4–109.1%). According to the investigation, this is the first successful application of HQ and CC in direct seawater detection. This work demonstrated the Co3O4/MWCNTs nanocomposite was a promising material for electro-catalysis and electro-analyst in the marine environment.

Development and use of metamaterials have been gaining prominence in large part due to the possibility of creating platforms with "disruptive" and unique optical properties. However, to date, the majority of such systems produced using micro or nanotechnology are static and can only perform certain target functions. Next-generation multifunctional smart optical metamaterials are expected to have tunable elements with the possibility of controlling the optical properties in real time via variation in parameters such as pressure, mechanical stress, and voltage or through nonlinear optical effects. Here, we address this challenge by developing a thermally controlled optical switch, based on the self-assembly of poly( N-isopropylacrylamide)-functionalized gold nanoparticles on a planar macroscale gold substrate. We show that such meta-surfaces can be tuned to exhibit substantial changes in the optical properties in terms of both wavelength and intensity, through the temperature-controlled variation of the interparticle distance within the nanoparticle monolayer as well as its separation from the substrate. This change is based on temperature-induced auxetic expansion and contraction of the functional ligands. Such a system has potential for numerous applications, ranging from thermal sensors to regulated light harnessing.

Seawater detection faces the serious interference that causes sensors lose effectiveness. ZnO/NiO core-shell p-n junction nanorods decorated metal foam was successfully fabricated and used as enzymes loading matrix to immobilize acetylcholinesterase for detection of Methyl Parathion (MP) in seawater. The lowest detection limit to MP in seawater was reduced more than an order of magnitude and the anti-interference ability was enhanced significantly by introducing the p-n junction interface. The results were attributed to the formed electrons well and the built-in electric field that provided a driving force for electrons signal transform. It is a promising strategy to solve the problem of the serious interference and the high detection limit in seawater detection.

The 3D ZnO/ZnFe2O4/graphene foam (ZZFO/GF) was successfully prepared by template method and hydrothermal process as a sensing platform for colorimetric detection of hydroquinone (HQ). It is found that the foam exhibited improved peroxidase-like activity that could quickly catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 and produced a blue color, which can be observed by naked eyes. And the HQ was detected by means of fading the color of the oxTMB, which is a sensitive and simple colorimetric method that is rarely used for detection of HQ. Therefore, a simple, sensitive and selective sensing platform was established. A good linear range from 0 to 150 μM and low detection limit of 3.75 μM was achieved. Furthermore, the materials could be easily recollected by applying a magnetic field. This method exhibited practical potential in environmental pollutant analysis and actual detection of HQ in local river water was achieved.

Detection of pollutants in seawater faces a great challenge of strong interference, and the facile detection method is lacked. The CoMn

Recently, photoelectrochemical (PEC) sensing based on light-induce electrochemical redox has emerged as a promising technique for trace heavy metal detection, due to its sensitivity and simplicity. However, the interfering species with similar redox potentials impose a challenge when such technique is to applied to complex detection scenarios such in seawater. In this work, by constructing a three-dimensional Ni/Co3O4/MnO2/chitosan (CS) heterostructure, we propose an alternative PEC method for detecting Cu2+. Instead of relying on redox, this method focuses on utilizing the change of the interfacial energy barriers. When light and the specifically absorbed Cu2+ interact with the heterojunctions, such two factors synergistically lower the energy barriers at the interface through electrostatic interaction, exponentially magnify the sensing signal of Cu2+ without involving redox, thus significantly improve both the sensitivity and specificity. The Ni/Co3O4/MnO2/CS sensor performs well in measuring real-life samples such as seawater, suggesting future applications of in-field detection of Cu2+ pollution.

Analytes with similar redox properties are normally difficult to distinguish through classic electrochemical methods. This becomes especially true for the on‐site detection in seawater where the high salinity and complex chemical components can impose severe interference. Hereby introducing numerous nanoscale heterojunctions in the Cu/CuO/reduced graphene oxide (rGO)/polypyrrole (PPy) and Cu/CuO/rGO/chitosan electrochemical sensors, tunable interfacial energy barriers to exponentially regulate the electrochemical signal can be constructed. Importantly, these energy barriers are independent to redox but closely related to the electrostatic interaction from absorbed charged analytes such as Hg2+ and Cu2+. Moreover, the similar sensing principle is also valid for the energy barriers in p‐n junctions as demonstrated in the Ni/NiO/ZnO/PPy sensor. The good anti‐interference properties and ultrahigh sensitivity of this sensing mode offers new opportunities in trace analyte detection in harsh environments such as seawater.

Solar steam generation has been considered one of the most promising approaches for dealing with the energy and freshwater resource crises in recent years. However, achieving high efficiency in photo-thermal conversion remains a considerable challenge. Here, a series of hierarchical Ti

The NiMn

The sensitive online detection technique for heavy metal ions present in ocean, while effectively eliminating the interference of other chemicals, has been lacking at the present time. We found that the interfacial barrier of ZnO/rGO/PPy heterostructure had powerful physical effects on electrochemistry, and the Schottky barrier driven electrochemical detection was further developed. As based on the interfacial physical barrier, it could avoid the existing problem of the traditional electrochemical sensing mechanism and apply in more interfering environment. The sensitive detection of trace mercury ion (Hg2+) in actual seawater was achieved by employing the ZnO/rGO/PPy heterostructure. The interfacial barrier effect provides a chance to develop sensors used in more interfering environment.

Improper addition of melamine in milk powder poses a threat to human health, but the interference of complex components makes the trace detection hard. The cerium dioxide@carbon quasi-aerogels (CeO2@C-QAs) with Schottky barrier was successfully prepared to detect melamine in milk powder. The interfacial effects of Schottky barrier on electrochemical detection are studied and find energy barrier can be used as a novel electrochemical driving factor to achieve anti-interference sensing. The highly sensitive detection of melamine was achieved at acidic and alkaline environments. It obtained the good recovery rate and exhibited anti-interference in real milk powder detection. The lowest detection limit (2.19 nM) was much lower than the international safety threshold of melamine content. It affords an inspiring chance to achieve anti-interference electrochemical detection by using the interfacial energy barrier effects.

Neutral N-pyrazolyl radicals [3,5-R2pz]• as reactive intermediates were generated by one-electron oxidization of the corresponding 3,5-disubstituted pyrazolato anions [3,5-R2pz]− (R = tBu, Ph) with BiCl3 and trapped by the use of 5,5-dimethyl-1-pyrroline-N-oxide as a spin trap, which was confirmed by electron paramagnetic resonance spectral analysis. With dimerization of the postulated pyrazolato low-valent BiII radical species, two novel paddlewheel pyrazolatodibismuthanes [L2(Bi–Bi)L2] [L = η1,η1-3,5-R2pz; R = tBu (5α, 5β, and 5γ), Ph (6)] were isolated and structurally characterized.

We present a new track reconstruction algorithm based on cellular automaton for AMS-02 experiment. This algorithm has already become one of the standard method in AMS-02 Monte Carlo simulation and data production. The performance of new track finding is shown in terms of CPU time, track efficiency, fake rate and charge confusion. With the new track finding algorithm, track reconstruction efficiency of 99% is achieved for both electron Monte Carlo simulation and ISS data. A comparison of new track finding and previous track finding for nuclei and γ event sample is shown as well.

Constructing schottky junction with zero-bandgap graphene was innovatively achieved by electrochemical reduction and deposition of GO on NiO foam directly. The fabricated 3D graphene/NiO foam exhibited highly efficient sensing performance towards positively charged dopamine molecules. The main mechanism is that the adsorbate-induced charges could change the schottky barrier height, following by selectively enhancing or depressing the electrochemical responses of different charged analytes. The proposed self-adjusting effects of schottky barrier on electrochemical signals were theoretically and experimentally explored in depth. As a result, it can help to break the limitation that analytes with similar redox properties are difficult to distinguish by electrochemical methods

A novel nonenzymatic glucose sensor based on Schottky interface was successfully fabricated by facile annealed and sputtering methods. The multiple catalysis effect of NiO, Au and 3D architecture improved the catalytic activity towards glucose. In addition, the biosensing performance was enhanced significantly due to the introducing of Schottky interface. Consequently, the fabricated biosensor demonstrated excellent performance in sensing glucose with a high sensitivity (6302.25 μA mM1 cm2), low detection limit (1.16 μM), good repeatability and long-term stability. The results indicated that introducing Schottky interface can be a promising strategy in the development of nonenzymatic glucose biosensors.

A novel strategy of using Schottky barrier as a controllable tuning factor for electrochemical detection was proposed. Our results showed that the Schottky barrier height could be tuned purposely by the charged characteristics of adsorbed molecules so that the electrochemical response could be controllably enhanced or weakened. The fabricated 3D Ni/ZnO/CQDs (carbon quantum dots) foam with Schottky interfaces was successfully employed for selective electrochemical detection of dopamine. It is an effective approach to overcome the limit of selective detection of targets with similar redox properties by using electrochemical method. Rational design of Schottky barrier is promising to develop new-type and more effective electrochemical sensors.

P -Type NiO foam with rough nanostructured surface was prepared by the surface treatment of Ni foam, and then it was decorated with n -type ZnO nanopyramids to construct a 3D p – n junction foam. The p–n junction foam was used for electrochemical detection of dopamine and the sensing performance was improved significantly compared with the single NiO and ZnO. High sensitivity (171 μA/mmol/L), fast response (2 s), excellent selectivity and stability were achieved. It was attributed to the introduction of numerous p – n junction interfaces, the interfacial potential barrier played as a tuning factor for the electrochemical determination of dopamine. The results demonstrated it would be an important way to improve the biosensing performance by introducing the p – n junction interfaces.