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2,5-Furandicarboxylic acid (FDCA) has the potential to replace terephthalic acid (TPA) as a building block in the preparation of bio-based and degradable polyester materials. However, the lack of efficient and stable catalysts limits the commercial viability of FDCA production. In this work, metalloporphyrins were immobilized on mesoporous SiO2 and used as a novel oxidase to convert 5-hydroxymethylfurfural (HMF) to FDCA. As the catalytic active center of P450 monooxygenases and horseradish peroxidase, supported palladium, manganese, ferri, and cobalt porphyrins via ionic-liquid-functionalized SiO2 (PdPOP-SiO2, MgPOP-SiO2, FePOP-SiO2 and CoPOP-SiO2) were able to simulate oxidase alone under mild conditions. 100% HMF (0.02 M) conversion and 94.94% FDCA yield were achieved using PdPOP-SiO2 as a biomimetic oxidase after a 12 h reaction at 373 K in water at atmospheric pressure. This type of mimetic oxidase is stable, inexpensive, and readily available, and the method developed in this work can potentially be used to oxidize HMF to FDCA in an industrial setting.

Quartz phenocrysts are common in many granites, volcanic rocks, metamorphic rocks and hydrothermal deposits. The Dongping porphyritic granite contains large amounts of rounded to sub-rounded quartz phenocrysts. Minerals in this porphyritic granite show weak but distinct orientation. Dense clusters of fluid inclusions and albite crystals exist in the quartz, showing snowball texture. Two types of snowball quartz are recognized: (1) large snowball quartz phenocrysts containing large albite grains distributed in the core and small albite grains distributed in the mantle, and (2) small snowball quartz crystals containing small albite grains. The granite is characterized by high SiO2 (7.15–73.44 wt%), K2O (4.70–5.10 wt%) and Na2O (4.93–5.21 wt%) contents, low CaO (0.41–0.71 wt%), MgO (0.03–0.05 wt%), Fe2O3 (0.87–0.94 wt%), TiO2 (0.02–0.03 wt%) and ΣREE (7.10–9.80 ppm) contents. The granite has similar mineral and chemical composition with the aplite in the area, and they were derived from the residual melt of the Shuiquangou magma that suffered assimilation fractional crystallization process. Fluid inclusions in the quartz phenocrysts have homogenization temperatures of 260–380 °C and salinities of 1.4–12.4 wt% NaCl equiv. for liquid + vapor type inclusions and 34.1–44.3 wt% NaCl equiv. for brine ones. The quartz phenocrysts exhibit homogeneous cathodoluminescence without growth bands or zoning. The trace element contents in the quartz phenocrysts are extremely low (Ti 3.4–5.1 ppm, Al 13–118 ppm, Li

Research of purely organic room-temperature phosphorescence (RTP) materials has been a hot topic, especially for those with stimulus response character. Herein, an abnormal stimulus-responsive RTP effect is reported, in which, purely organic luminogen of Czs-ph-3F shows turn-on persistent phosphorescence under grinding. Careful analyses of experimental results, coupled with the theoretical calculations, show that the transition of molecular conformation from quasi-axial to quasi-equatorial of the phenothiazine group should be mainly responsible for this exciting result. Furthermore, the applications of stylus printing and thermal printing are both successfully realized, based on the unique RTP effect of Czs-ph-3F.

In this study, a novel P2-type sodium manganese oxide is presented using a facile preparation method. With the help of titanium doping, and introduction of interstitial water, the electrochemical p...

With the desire to realize both high capacity and high voltage, a series of materials xLi2MnO3·(1-x)NaNi1/3Co1/3Mn1/3O2 (0.5 ≥ x ≥ 0.2) are designed and prepared, which is inspired by the idea from Li-excess materials (the addition of extra lithium, manganese and charge-compensating oxygen lead to formation of structurally integrated xLi2M′O3·(1-x)LiMO2, M′ = Mn or Ti and M = Mn, Co or Ni typically). The addition of Li2MnO3 is intended to enhance the high voltage operation of sodium ternary system NaNi1/3Co1/3Mn1/3O2. X-ray diffraction patterns show that the materials are prone to form P2-type structure with the increment of Li2MnO3. Rate capability and cycle performance indicate that a more stable structure tends to be distinguishable when the content of Li2MnO3 exceeds 0.3. It is manifested that the introduction of Li2MnO3 not only plays important role in enhancing interface stability but also prevents from dramatic side reaction with electrolyte during high voltage operation.

The Dongping gold deposit is located near the center of the northern margin of the North China Craton. It is hosted in the Shuiquangou syenite and characterized by large amounts of tellurides. Numerous studies have addressed this deposit; the mineral paragenesis and ore-forming processes, however, are still poorly studied. In this contribution, a new mineral paragenesis has been evaluated to further understand ore formation, including sulfides (pyrite, chalcopyrite, galena, sphalerite, molybdenite, and bornite), tellurides (altaite, calaverite, hessite, muthmannite, petzite, rucklidgeite, sylvanite, tellurobismuthite, tetradymite, and volynskite), and native elements (tellurium and gold). Molybdenite, muthmannite, rucklidgeite, and volynskite are reported for the first time in this deposit. We consider the Dongping gold deposit mainly formed in the Devonian, and the ore-forming processes and the physicochemical conditions for ore formation can be reconstructed based on our newly identified ore paragenesis, that is, iron oxides -> (CO₂ effervescence) -> sulfides -> (fTe₂/fS₂ ratio increase) -> Pb-Bi-tellurides -> (condensation of H₂Te vapor) -> Au-Ag-tellurides -> (mixing with oxidizing water) -> carbonate and microporous gold -> secondary minerals -> secondary minerals. The logfO₂ values increase from the early to late stages, while the fH₂S and logfS₂ values increase initially and then decrease. CO₂ effervescence is the main mechanism of sulfides precipitation; this sulfidation and condensation of H₂Te vapor lead to deposition of tellurides. The development of microporous gold indicates that the deposit might experience overprint after mineralization. The Dongping gold deposit has a close genetic relationship with the Shuiquangou syenite, and tellurium likely originated from Shuiquangou alkaline magmatic degassing.

In this work, a ratiometric fluorescent probe (RF-probe) for highly sensitive and selective detection of uric acid was reported for the first time toward H2O2 based on inner filter effect (IFE) between bimetallic gold/silver nanoclusters (Au/Ag NCs) and 2,3-diaminophenazine (DAP). For this RF-probe, uric acid was degraded to allantoin and H2O2. Upon the addition of HRP, o-phenylenediamine (OPD) could be catalytically oxidized to DAP in the presence of H2O2, then the fluorescence intensity corresponding to DAP at 580 nm increased dramatically with a fluorescence quenching of BSA-Au/Ag NCs at 690 nm, resulting in a RF-probe toward uric acid. This RF-probe allowed for the sensitive detection of uric acid in range of 5.0 × 10−6 M to 5.0 × 10−5 M with a detection limit (S/N = 3) as low as 5.1 × 10−6 M. At the same time, it has been successfully used for uric acid levels detection in human serum, and the results are consistent with those of the hospital. RF-probe built may provide a ratiometric fluorescence universal platform for detection of various species involving in the production of H2O2 in other biological systems.

The Yinachang Fe-Cu-Au-U-REE deposit is located in the Kangdian region at the southwestern margin of the Yangtze Block. This contribution presents petrological, geochronological, whole rock geochemical, and Rare Earth Elements (REE) geochemistry of zircons of gabbro and diorite dykes associated with the Yinachang Fe-Cu-Au-U-REE deposit, aiming to constrain the age of the mineralisation and help refine our understanding of the tectonic setting of the region. Zircons from diorite have a Palaeoproterozoic U-Pb age of 2014 ± 30 Ma, and zircons from the gabbro could not be dated because they are metamict, having a high concentration of uranium. The ca. 2014 Ma age of the zircons in the diorite indicates that the southwestern part of the Yangtze Block is partly synchronous with the Columbia Supercontinent. Geochemically, the diorite and gabbro are enriched in large-ion lithophile elements (LILEs) such as Rb and U, and depleted in high-field-strength elements (HFSEs) such as Nb, P, Ti, Ba, and Sr. The diorite is enriched in light REEs (LREEs) and has a slight to negligible Eu anomaly, which are characteristic of ocean-island basalts containing mantle-derived high potassic calc-alkaline rocks. In contrast, the gabbro is weakly enriched in LREEs and has a slightly negative Eu anomaly similar to those of potassic calc-alkaline enriched mid-ocean-ridge basalt. The average combined REE content of zircons from the gabbro is 19401 ppm and is significantly higher than that of the zircons from the diorite averaging 1020 ppm. This indicates that the gabbro is closely related with the REE mineralisation at the deposit. The geochemistry of the diorite indicates that it formed at the continental margin of a volcanic-arc. It also indicates that the magmatic rocks in the region have a possible mantle plume origin contaminated by crustal material and located at a transitional zone between a rift and an ocean-continent tectonic setting.

A novel fluorescent sensor based on bovine serum albumin stabilized gold/silver nanoclusters (BSA-Au/Ag NCs) was developed for sensitive and facile detection of alkaline phosphatase (ALP) activity. For this fluorescent sensor, ascorbic acid 2-phosphate (AAP) was decomposed into ascorbic acid (AA) and phosphate by catalysis with ALP. The initial red fluorescence of the BSA-Au/Ag NCs was effectively quenched by KMnO4 and then the fluorescence was recovered by addition of AA. The mechanism of interaction between BSA-Au/Ag NCs and KMnO4 and AA was studied with use of the fluorescence lifetime and UV-vis absorption spectra. The results indicated that the oxidation/reduction modulated by KMnO4/AA led to surface structure destruction/restoration of the BSA-Au/Ag NCs, resulting in fluorescence quenching/recovery. The proposed fluorescence-based method based on a dark background was used to detect ALP and had excellent sensitivity, with a detection limit of 0.00076 U/L. Moreover, the method was applied to the determination of added analytes, with satisfactory recoveries (97.0–105.0 %). In a simulated eutrophic water body, this method successfully detected ALP in actual water samples and could monitor the dynamic changes of ALP activity through visual observation. More importantly, the proposed fluorescent sensor not only has the advantages of simple operation and high sensitivity but has also been successfully used on filter paper to establish a rapid and visual test paper for ALP.

The Qiaoxiahala Fe-Cu-(Au) deposit (1.44 Mt ore @ 43–53% Fe, 0.55–2.21% Cu and 0.13–2.4 g/t Au) is located in the northern margin of East Junggar terrane, NW China. The deposit is hosted in the upper part of the Middle Devonian Beitashan Formation mafic and felsic volcanic rocks and sedimentary interbeds, and is spatially closely related to local fractures. Six hypogene hydrothermal stages have been identified, including (Stage I) early skarn, (Stage II) late skarn, (Stage III) magnetite mineralization, (Stage IV) magnetite-pyrite mineralization, (Stage V) chalcopyrite mineralization and (Stage VI) late veins. These six stages include three major mineralization events, as represented by the (Stage III) magnetite-epidote-K-feldspar-quartz-calcite, (Stage IV) magnetite-pyrite-garnet-quartz-calcite and (Stage V) chalcopyrite-chlorite assemblages. The Stage III magnetite mineralization fluids were likely of high temperature (354–386 °C), low-medium salinity (9.9–14.7 wt% NaCl equiv.), Mg/Fe-rich and organic-rich with lithostatic pressure of 1.3–1.5 kbar and corresponding depth of 4.3–4.8 km. Oxygen and hydrogen isotopes showed that the 18O-rich (9.7–11.2‰) and D-rich (−26.3‰) fluids were possibly modified from the Early Carboniferous seawater interacting with the Beitashan Formation organic-rich limestone or tuff. In comparison, the Stage IV magnetite-pyrite mineralization fluids were likely of medium-high temperature (272−453 °C), low-medium salinity (2.9–19.5 wt% NaCl equiv.), Mg/Fe-rich, with pressure of 0.8–1.2 kbar and corresponding depth of 2.6–4.0 km. The Stage V chalcopyrite mineralization fluids were likely of low-medium temperature (186−270 °C), low-medium salinity (1.4–21.8 wt% NaCl equiv.), Ca- or Na-rich, with pressure of 0.4–0.6 kbar and corresponding depth of 1–2 km. Hydrogen and oxygen isotopic compositions (Stage IV: δDwater = −141 to −92‰; δ18Owater = 8.9–11.1‰; Stage V: δDwater = −104‰; δ18Owater = 7.2‰) suggest that the ore fluids were of connate marine origin. Furthermore, Stage IV δ13Cwater values (−0.6 to 0‰) also indicate interactions between seawater and sedimentary wall-rocks. The negative sulfur isotopic compositions of chalcopyrite and pyrite (−4.2 to −0.2‰) may demonstrate a biogenic sulfur source. Compared with the arc-related IOCG deposits in the central Andean orogen, the Qiaoxiahala Fe-Cu-(Au) deposit shares many common features in geology, mineralization, alteration and various sources of fluids, indicating a possible IOCG-like mineralization-style and potential to discover other Late Paleozoic arc-related IOCG deposits in East Junggar.

The Halasu III deposit, an important Cu deposit in the southernmost part of the Halasu porphyry Cu belt, is situated in the East Junggar block in NW China. Copper and Mo sulfide mineralization commonly occurs as disseminations or veinlets, and is mainly associated with Devonian granodiorite porphyry. Our detailed field geological investigation identified late-stage high grade Cu sulfide-bearing veining superimposed on the earlier porphyry Cu–Mo mineralization. Four hydrothermal alteration and mineralization stages were identified, namely the early epidote alteration (Stage I), porphyry-style alterations (Stage II comprising II-A potassic, II-B propylitic and II-C phyllic alteration sub-stages), late veining (Stage III) and supergene processes (Stage IV) in the northern- and southern mineralization zones at Halasu III. Multiphase granodiorite- and alkali granite dykes intruded the Beitashan Formation volcanic rocks, generating the early epidote alteration. Potassic alteration (Stage II-A) occurred in and around the NNW-treading granodiorite dykes, while the propylitic alteration (Stage II-B) occurred in the intrusions or volcanic wall rocks around the potassic zone. These early alteration assemblages were overprinted by the subsequent, structurally-controlled phyllic alteration (Stage II-C) confined within the granodiorite porphyry. Late veins (Stage III) include sulfide-bearing (Stage III-A) and sulfide-barren (Stage III-B) ones. Supergene process (Stage IV), represented by hematite and jarosite replacing primary sulfides, extends tens of meters down depth and is commonly fracture-controlled. Three fluid inclusion (FI) types were recognized, namely Type A (single-phase), B (liquid–vapor two-phase) and C (liquid–vapor–solid three-phase). For Type B FIs, those of potassic alteration homogenized at 183–347 °C, with corresponding salinities of 6.2–17.8 wt.% NaCl equiv. The propylitic and phyllic FIs homogenized at 172–425 °C and 231–352 °C, respectively, with the corresponding salinities of 0.9–14.0 wt.% NaCl equiv. and 0.4–10.5 wt.% NaCl equiv. The sulfide-bearing vein FIs homogenized at 243–410 °C (Stage III-A-1), 260–362 °C (Stage III-A-2) and 117–235 °C (Stage III-A-3), along with the corresponding salinities of 1.9–9.2 wt.% NaCl equiv., 1.1–6.7 wt.% NaCl equiv. and 6.5–17.1 wt.% NaCl equiv., respectively. The sulfide-barren vein FIs yielded homogenization temperatures of 260–380 °C (Stage III-B-1) and 114–297 °C (Stage III-B-2), with corresponding salinities of 1.7–9.8 wt.% NaCl equiv. and 0.2–13.6 wt.% NaCl equiv., respectively. We suggest that hydrothermal veins at Halasu III may have undergone complex and superimposing alteration due to the episodic reopening of the preexisting veins, with Stage III-A-3 veining overprinting the phyllic alteration and Stage III-A-2 veining. Stage III-B-2 veining superimposed on the potassic alteration, as well as on Stages III-A-1 and III-B-1 veining. Paragenetic sequence and fluid evolution at Halasu III indicate that these complex hydrothermal alteration stages were formed in accordance with the regional tectonic evolution. These various alteration and mineralization stages at Halasu III deposit reveal a prolonged history of magmatic and hydrothermal processes extending episodically from the Middle Devonian to Middle Permian, wherein early mineralization was overprinted by late hydrothermal events. Such superimposed mineralization may occur commonly in the Paleozoic Central Asia Orogenic Belt.

Zearalenone (ZEN) has a potential hazard to human health, and is frequently found in agro-products. To minimize ZEN exposure to consumers, a novel metal-organic framework-based immunoassay system using zeolitic imidazolate framework-encapsulated horseradish peroxidase and goat anti-mouse IgG (HRP/Ab@ZIF-L) as labels was proposed for rapid and ultrasensitive detection of ZEN in agro-products. The HRP/Ab@ZIF-L not only maintained recognition ability of antibody and catalytic activity of enzyme, but also protected encapsulated proteins against high temperature, organic solvents and long term storage. Under optimal conditions, the detection limit of HRP/Ab@ZIF- L -based immunoassay reached 0.5 ng/L for ZEN, which was approximately 126-fold lower than that of conventional HRP-based immunoassay. Moreover, the proposed method showed an excellent selectivity, and a good dynamic linear detection for ZEN in the range of 0.5 ng/L to 0.476 μg/L. The recoveries of ZEN from spiked corn and wheat samples ranged from 84.50% to 96.70% with the relative standard deviation under 8.9%. In brief, the proposed immunoassay method has potential application for rapid and ultrasensitive detection of ZEN in agro-products.

Zearalenone (ZEN) is a prevalent mycotoxin that needs intensive monitoring. A semi-quantitative and quantitative immunochromatographic assay (ICA) was assembled for investigating ZEN contamination in 187 samples of cereal and their products from China in 2019. The semi-quantitative detection model had a limit of detection (LOD) of 0.50 ng/mL with visual judgment and could be completely inhibited within 5 min at 3.0 ng/mL ZEN. The quantitative detection model had a lower LOD of 0.25 ng/mL, and ZEN could be accurately and digitally detected from 0.25&ndash, 4.0 ng/mL. The ICA method had a high sensitivity, specificity, and accuracy for on-site ZEN detection. For investigation of the authentic samples, the ZEN-positive rate was 62.6%, and the ZEN-positive levels ranged from 2.7 to 867.0 ng/g, with an average ZEN-positive level being 85.0 ng/g. Of the ZEN-positive samples, 6.0% exceeded the values of the limit levels. The ZEN-positive samples were confirmed to be highly correlated using LC-MS/MS (R2 = 0.9794). This study could provide an efficiency and accuracy approach for ZEN in order to achieve visual and digitized on-site investigation. This significant information about the ZEN contamination levels might contribute to monitoring mycotoxin occurrence and for ensuring food safety.

We aimed to establish an automated versatile sample preconcentration method based on the modified immunomagnetic beads, which was utilized to enrich for aflatoxin B1 from the matrices. The critical main parameters affecting the extraction efficiency, such as usage amount of immunomagnetic beads, reaction time, elution time, and blending way were investigated. Under the optimized conditions, the content of aflatoxin B1 was analyzed by high-performance liquid chromatography, the mobile phase consists of water-acetonitrile-methanol (42:18:10, v/v/v), and fluorescence detection was performed with excitation and emission wavelengths at 360 and 440 nm, respectively. Moreover, the performance of preconcentration method was compared with the conventional method based on the immunoaffinity column. The accuracy of two clean-up methods was within the error range. In addition, the stability and recyclability of the immunomagnetic beads was studied by recycling them five times. The results for the respective analysis in various samples demonstrated that the developed extraction platform provides a promising approach that is simple, rapid, sensitive, and easy to use.

The Cuihongshan deposit is a giant Fe-polymetallic skarn deposit located in the northern zone of the Lesser Xing'an-Zhangguangcai Range (LXZR), NE China. It is predominantly hosted in skarn contact zones between marble and alkali-feldspar granites and monzogranites, with minor in fracture zones of granodiorites. Because of dense vegetation cover, complex intrusions, and contact relation between orebodies and rocks, the metallogenesis of the deposit is poorly understood. Here, we present detailed whole-rock geochemistry, zircon U-Pb geochronology of granitoids, and molybdenite Re-Os isotopic dating data. All of the granitoids in the Cuihongshan deposit area are silica and potassium rich, highly fractionated, showing affinities to high-fractionated I-type granites. However, compared with the other granitoids, the Late Triassic alkali-feldspar granites have higher differentiation index, stronger enrichment in F, W, Mo, Pb, Th, U, and volatiles with partial mineralization. The zircon U-Pb dating of the granodiorite, monzogranite, and alkali-feldspar granite yielded weighted average ages of 493 +/- 4, 194 +/- 1, and 204 +/- 1Ma, respectively. The Re-Os dating of molybdenites from the Cuibei and Cuizhong ore sections yielded isochron ages of 205 +/- 2 and 204 +/- 4Ma, respectively, which are consistent with the emplacement age of the alkali-feldspar granite. Combined with the lines of evidence from the contact relationship between the orebodies and alkali-feldspar granite, the disseminated mineralization and the enrichment in ore-forming elements and volatiles in the alkali-feldspar granite, these indicate that the Late Triassic alkali-feldspar granite rather than the monzogranite as previously reported, has a close genetic relationship with the Cuihongshan deposit. In addition, the alkali-feldspar granites occur as apophyses and dikes, but the Late Cambrian and Early Jurassic granitoids occur as batholiths. This indicates that, according to the theory that small intrusions form large deposits, a potential Late Triassic (similar to 204Ma) buried batholith might have provided abundant ore-forming materials. However, the top parts of the Late Cambrian and Early Jurassic granitoids have been denudated, which is unfavourable for significant deposit preservation and mineralization related to the 2 stages of granitoids. This study gives a significant suggestion that exposed, and blind apophyses and dikes should be further considered in the exploration and study of metal deposits in NE China. Three phases of mineralization occurred in the LXZR in the Triassic-Jurassic, namely, porphyry-skarn Cu-Mo polymetallic mineralization (similar to 250-240Ma), skarn Fe-Pb-Zn polymetallic mineralization (similar to 204-190Ma), and porphyry Mo polymetallic mineralization (similar to 180-160Ma). On the basis of regional data, the LXZR experienced subduction and collisional settings during similar to 260-185Ma and similar to 180-160Ma, respectively. Hence, the Early Triassic (similar to 250-240Ma) and Late Triassic-Early Jurassic (similar to 204-190Ma) mineralizations represented by the Baoshan and Cuihongshan deposits, respectively, are related to the early and late subduction of the oceanic plate between the Songliao and Jiamusi massifs beneath the Songliao Massif, respectively. This also indicates a potential mineralization in the LXZR in the Middle Triassic. However, the genesis of the late large-scale porphyry Mo polymetallic deposits (similar to 185-160Ma; e.g. , Daheishan, Luming, Huojihe, Xinghualong, Xingshan, and Wulugetushan deposits) is constrained by the collision of the Songliao and Jiamusi massifs.

Herein, a simple and cost-effective chemiluminescence immunoassay combined with the magnetic particles (MPCLIA) is presented for the rapid detection and analysis of Aflatoxin B1, which is a potent carcinogen found in the environment. Several physicochemical factors that potentially influence the assay performance of the proposed method were investigated in detail, including concentrations of FITC-labelled antibody, AFB1-alkaline phosphatase and magnetic particles concentration. Under the optimized experiment condition, the method showed: (i) a low limit detection of 0.05 ng/mL; (ii) satisfactory recoveries in real grain and oil samples ranging from 78% to 109%, which was well within the requirement of residue analysis, and (iii) excellent sensitivity, wide dynamic range and easy to separate in the washing process, which was superior to enzyme-linked immunosorbent assay (ELISA) method. In addition, the device used is of low cost. Moreover, the MPCLIA results for the real samples were in good agreement with that obtained by the high-performance liquid chromatography. These results suggest that the proposed MPCLIA method has potential application for screening other toxic mycotoxins occur in the food industry or other applied fields.

The potential homogeneous assay employing immunomagnetic beads (IMB) has been receiving attention as a screening tool in food-safety control; the method is simple, efficient, and does not require long incubation times or complex separation steps. In this study, a homogeneous immunoassay has been successfully developed and applied in the determination of aflatoxin B1 (AFB1) contamination in agricultural products by coupling IMB and the biotin-streptavidin (BSA) (BSA-IMB) system. Under optimal conditions, the limit of detection (LOD, IC10), half-maximal inhibition concentration (IC50) and detection range (IC20–IC80) of BSA-IMB are 0.00579, 0.573 and 0.0183–17.9 ng mL−1, respectively, for AFB1. The detection of AFB1 by BSA-IMB can be achieved in 40 min (ELISA needs at least 180 min). The cross-reactivities of BSA-IMB with its analogues are negligible (

Sodium ion batteries (SIBs) are considered as a promising candidate in the field of large-scale power grids and power storage, owing to their abundant reserves and low price. As a promising intercalated SIBs electrode, vanadium-based compounds have multiple oxidation states, rich coordination polyhedron structure and open lattice frameworks. But those materials are prone to occur the irreversible electrochemical reactions and produce metastable structural materials in the process of electrochemical reaction, resulting in a rapid decrease in capacity. Herein, a novel bilayer-structured vanadium oxide (CaV8O20·3H2O)/Carbon composite material with high specific capacity and long cycling life was synthesized. The CaV8O20·3H2O in this research has overcome the shortcomings of most vanadium-based electrode materials. In the ex-situ mechanism of this study, it was proved that the insertion of calcium ions can effectively maintain the stability of the interplanar spacing of the material and carry out sufficient redox reactions. Combined with the results of electrochemical performance comparison and mechanism analysis, a uniform carbon coating can improve the electrochemical stability and specific capacity of CaV8O20·3H2O by increasing the conductivity of the material and inhibiting adverse side effects. The reported V-based carbon composite anode material exhibited a remarkable electrochemical property with a capacity of 0.2 A g−1 and the capacity retention rate was 92.7% after 200 cycles, and the capacity retention rate was 72% after 450 cycles at a current density of 5.0 A g−1. The novel pre-intercalation model may provide a new perspective for the development of vanadium-based materials in SIBs.

The Shuangwang gold deposit, located in the Fengxian-Taibai fore-arc basin in the western Qinling Orogen of Central China, has yielded over 70 tons of gold. It is an orogenic gold deposit occurring in an NW-trending breccia belt. Most of the ores are hydrothermal breccia type containing fragments of adjacent strata cemented by ankerite and pyrite. Pyrite is the most abundant metallic mineral and the major gold-bearing mineral in the ores. A total of 58 pyrite samples from main ore bodies of the Shuangwang gold deposit have been analysed for 44 trace elements by HR-ICP-MS. Sb, Ba, Cu, Pb, Zn, Bi, Mo, Co are selected as indicator elements to investigate the potential usefulness of trace elements in pyrite as an indicator in gold exploration. The results show that the supra-ore halo elements Sb and Ba, which may have been more active than other near-ore halo elements and sub-ore halo elements, are best to characterize the shape of ore bodies. Five target areas are pointed out for deep ore exploration based on a comprehensive study of supra-ore, near-ore and sub-ore halos. This study provides evidence that trace elements in pyrite can be used to depict the deep extension of ore bodies and to vector towards undiscovered ore bodies.

Tetrabromobisphenol A bis(2-hydroxyethyl) ether (TBBPA DHEE), as one of the TBBPA derivatives, is frequently applied as a flame retardant. To date, however, little evidence has been gathered regarding its environmental behavior and fate. This is mainly attributed to the lack of an analytical approach available to measure it. Mass spectrometry cannot determine levels of TBBPA DHEE. LC-MS could not ionize TBBPA DHEE to yield enough fragments, while GC-MS could not be applied for the analysis either, due to the thermal degradation of TBBPA DHEE. We here designed a novel hapten, then conjugated it with a carrier protein and produced a type of polyclonal antibody capable of recognizing TBBPA DHEE. Based on this approach, a sensitive and high-throughput indirect competitive enzyme-linked immunosorbent assay (ELISA) was established. The respective detection limit (LOD, based on 90% B/B0) and IC50 calculated from the standard curve were 0.702 and 9.868 ng/mL for TBBPA DHEE. And the established method showed good tolerance to various matrix interferents. Using our ELISA, we measured the concentrations of these substances from environmental water samples with no pretreatment other than filtration. We found the presence of TBBPA DHEE in environmental water samples collected in Jiangsu province, and the detected concentrations ranging from 1.5 to 7.7 ng/mL. Our proposed method here could be applied to completely and systematically investigate TBBPA DHEE and TBBPA MHEE concentrations in environmental samples.

The Paleoproterozoic granitoid rocks in the Jiaobei Terrane, which lies in the southern part of the Jiao–Liao–Ji Belt (JLJB) in China, provide valuable information on the tectonic and evolutionary history of the North China Craton (NCC). SHRIMP U–Pb dating of zircons from the Muniushan Monzogranite in the Guocheng gold deposit area, as well as in situ Hf isotope analyses of the zircons, were used to constrain the ages of emplacement and metamorphism, and to understand the petrogenesis of the granite. The geochronological data show emplacement ages of ca. 2.1 Ga and metamorphic ages of ca. 1.85 Ga. The magmatic cores of the zircons have eHf(t) values of −0.51 to 4.00 (average 1.98) and depleted mantle two-stage model ages (TDM2) of 2444–2703 Ma (average 2563 Ma). The rocks show the same trends of crustal evolution as ca. 2.5 Ga tonalite–trondhjemite–granodiorite (TTG) rocks in the Jiaobei Terrane, indicating that they were formed by the remelting of those TTG rocks. The Muniushan Monzogranite is part of a linear belt of ca. 2.2–2.0 Ga Paleoproterozoic granitoids within the JLJB. The granitoids are A-types, and are accompanied by coeval mafic intrusions and bimodal volcanic rocks, thus indicating widespread extension along the JLJB in the period 2.2–2.0 Ga. The ca. 1.85 Ga metamorphism was related to the collision of the Longgang and Nangrim blocks. The Paleoproterozoic evolution of the NCC constrains the crustal architecture and the source of Mesozoic granitoids in the Jiaobei–Sulu region. Inherited zircons of Paleoproterozoic age are widespread in the Mesozoic granitoids. In addition, Paleoproterozoic ages have been reported from lower crustal granulite xenoliths in the Sulu Orogen, and the southeastern margin of the NCC mirrors the evolution of the JLJB. It is probable, therefore, that NCC lower crust underlies the Sulu Orogen, and that the NCC was the main source for the Mesozoic granitoids in the Jiaobei–Sulu region. This view is consistent with the appearance of inherited zircons of Archean and Paleoproterozoic age on both sides of the orogen, normal δ18O values of magmatic zircons, and Paleoproterozoic to Archean two-stage Hf model ages for the granitoids.

Due to the harmful nature of 4,4′-diaminobiphenyl (DABP) to the environment and human health, the determination of DABP is of great significance and has received great attention. However, there is no electrochemical method reported to detect DABP. In this paper, perylenetetracarboxylic acid (PTCA) noncovalently functionalizes carbon nanohorns (PTCA-CNHs) nanohybrids were produced using a simple method and applied for the first electrochemical sensing of DABP. Herein, PTCA has two key advantages for functionalizing CNHs in DABP analysis: (I) PTCA could improve the dispersibility of CNHs in water and (II) enhance the accumulation capacity of DABP on PTCA-CNHs surface by means of the electrostatic interactions between PTCA (negative) and DABP (positive). The results show that the oxidation current of DABP at the PTCA-CNHs modified screen printed carbon electrode (SPCE) is much higher than that of the CNHs/SPCE and bare SPCE. The PTCA-CNHs/SPCE has a linear response range of 5.0 to 400.0 nM with a detection limit of 1.8 nM towards DABP detection.

Iron and Magnesium isotopes have been increasingly widely applied to trace mineralization processes of hydrothermal ore systems. In this study, Fe and Mg isotope compositions of whole-rocks, Fe-bearing minerals (pyrite and ankerite) and Mg-bearing mineral (ankerite) from the Shuangwang gold deposits are investigated to evaluate Fe and Mg isotope behaviors in a gold deposit hydrothermal system and provide new constraints on ore-forming processes. The results showed that the magmatic rocks in the Shuangwang gold deposit (mainly granodiorite , monzonitic granite and lamprophyre) yielded δ 56Fe values of 0.05–0.10‰ and δ26 Mg values concentrated in a narrow range from −0.23‰ to −0.21‰. The gold orebodies are hosted by a NW-trending breccia belt. The wall rock samples (mainly argillaceous limestone, carbonaceous slate and albitite) have higher δ 56Fe values of 0.12–0.29‰ and a wide δ26 Mg range from −2.54‰ to −0.35‰. Pyrite mineral separates show larger δ 56 Fe variation from −0.44‰ to 0.16‰, whereas ankerite has a small δ 56Fe range from −0.15‰ to −0.06 and a δ26Mg range from −0.66‰ to −0.35‰. The crystallization of magmatic rocks incorporated preferentially heavy Fe isotopes, resulting in enrichment of light Fe isotopes in the residual fluid exsolved from magma . The interactions between the wall rocks and the fluids resulted in increase of δ 56Fe value in fluids and resulted in decrease of δ56Fe value in the wall rocks. However, the fluid still had much lighter Fe isotope composition. Thus, Fe in the main ore-forming stages is regarded as derived from the magmatic stock. The opposite enrichment in Fe isotopes between pyrite and ankerite from stages II and III may be explained by equilibrium Fe isotope fractionation in an open system. In addition, the negative δ56Fe value in pyrite from stage IV is indicative of the equilibrium between FeS and dissolved Fe in a closed system. The exsolved fluid from magma has Mg isotope composition similar to magmatic rock, and the water–rock reaction led to the enrichment of heavy Fe isotopes in fluid. The evolutions of Mg isotopes in stages II and III precipitation matched well with the prediction of Rayleigh fractionation model. The Mg from wall rocks contributed to the composition of hydrothermal magnesium isotopes during the formation of the Shuangwang gold deposit. A multi-origin is supposed whereby the main stage ore-forming fluids were derived from metamorphic water and were affected by the influx of magmatic water.

On the basis of H2O2-mediated growth of gold nanoparticle (AuNPs), a novel plasmonic enzyme-linked immunosorbent assay (pELISA) was developed with a polyclonal antibody for the ultrasensitive simultaneous naked-eye detection of tetrabromobisphenol A bis(2-hydroxyetyl) ether (TBBPA DHEE) and tetrabromobisphenol A mono(hydroxyethyl) ether (TBBPA MHEE), one of the major derivatives and byproducts of tetrabromobisphenol A (TBBPA), respectively. In this modified indirect competitive pELISA, glucose oxidase (GOx) played an important role leading to the growth of AuNPs through a reaction between GOx and glucose to produce hydrogen peroxide (H2O2). In addition, further signal amplification was achieved via a large number of GOx molecules, which were immobilized on silica nanoparticles carrying poly brushes (SiO2@PAA) to increase the enzyme load, and the whole complex was conjugated on the second antibody. Under the optimized conditions, 10–3 μg/L TBBPA DHEE can be distinguished via the observation of a colored so...

The Wunugetushan porphyry Cu–Mo deposit is located in northeastern China. The deposit lies within the Mongolia–Erguna metallogenic belt, which is associated with the evolution of the Mongol–Okhotsk Ocean. The multiple episodes of magmatism in the ore district, occurred from 206 to 173 Ma, can be divided into pre-mineralization stage (biotite granite), mineralization stage (monzogranitic porphyry and rhyolitic porphyry), and post-mineralization stage (andesitic porphyry). The biotite granite has (87Sr/86Sr)i values of 0.704105–0.704706, eNd(t) values of −0.67 to −0.07, and eHf(t) values of −0.4 to 2.8, yielding Hf two-stage model ages (TDM2) 1250–1067 Ma, and Nd model ages of 1.04–0.96 Ga, indicating that the pre-mineralization magmas were generated by the remelting of Neoproterozoic juvenile crustal material. The monzogranitic porphyry has (87Sr/86Sr)i values of 0.704707–0.706134, eNd(t) values of 0.29–1.33, and eHf(t) values of 1.0–2.9, yielding TDM2 model ages of 1173–1047 Ma. The rhyolitic porp...

Lanthanide ions, the excellent fluorescence markers, have the potential to simplify the performance of multi-analytes analysis. In this work, a powerful time-resolved fluoroimmunoassay (TRFIA) based on dual-labeled format were performed for detecting clenbuterol and salbutamol simultaneously in water and swine feed samples. Europium (Eu3+)-labeled goat anti-mouse IgG and Samarium (Sm3+)-labeled goat anti-rabbit IgG were prepared and used as fluorescent probes. Under optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (LOD, IC10) of the TRFIA were 0.263 and 0.007 ng/mL for clenbuterol, and 0.179 and 0.014 ng/mL for salbutamol, respectively. The cross-reactivities of the TRFIA between these two β2-agonists and with their analogues were negligible, thus indicated high specificity and promoted the simultaneous determination. The spiked recoveries were 72.2%–102.2% with relative standard deviations (RSDs) of 3.4–13.8% for clenbuterol and salbutamol in water and swine feed samples. Furthermore, the results of TRFIA correlated well with those obtained by HPLC. The proposed dual-labeled TRFIA was a satisfactory tool for simultaneous, sensitive, efficient and labour-saving detection of clenbuterol and salbutamol in water and swine feed samples.

The Badaguan porphyry Cu Mo deposit is located in the Derbugan metallogenic belt of northeastern Inner Mongolia, China. The host granodioritic porphyry and the wall rock granitic porphyry were emplaced at 230 Ma and 238 Ma, respectively. The granodioritic porphyry has ( 87 Sr/ 86 Sr) i values of 0.70535–0.70549, e Nd (t) values of 0.41–1.17, e Hf (t) values of 1.30–6.51, and two–stage model ages (T DM2 ) of 1131–848 Ma. In contrast, the granitic porphyry is characterized by e Hf (t) values from − 0.75 to 7.28 that yield T DM2 model ages of 1355–816 Ma. The geochemical and Sr Nd Hf isotopic data for the magmatic rocks associated with the Badaguan porphyry Cu Mo deposit indicate that these intrusions were generated by the partial melting of juvenile lower crust. The δ 18 O values of ore fluids from different mineralizing stages are between − 6.0‰ and + 1.5‰, and the fluid δD water values vary from − 119.3‰ to − 140.0‰, indicating a mixed fluid of magmatic and meteoric water, the S Pb isotopes show that the metal was mostly derived from a deep-seated magma that involved some crustal materials, with a narrow δ 34 S range (− 2.4‰ to + 3.5‰). We infer that the Badaguan porphyry Cu Mo deposit formed during a period of southeast–directed subduction of the Mongol–Okhotsk oceanic plate beneath the Erguna Block.

The giant Shangfanggou skarn-porphyry Mo–Fe deposit, one of the largest Mo deposits in the East Qinling Orogen, is hosted by the Neoproterozoic Luanchuan Group on the southern margin of the North China Craton. The mineralization occurs mainly as veinlets and in veinlet-disseminated form within altered schists, skarns, hornfelses, and/or marbles. The hydrothermal alteration and mineralization at Shangfanggou took place over four stages. Stage 1 involved potassic alteration and silicification in the porphyry, skarnization and magnetization in carbonate strata, and hornfelsization in schists. Quartz–molybdenite veins associated with phyllic alteration were produced in the porphyry during stage 2, along with sericitization, chloritization, serpentinization, and silicification in the skarns, hornfelses and/or marbles. Quartz–polymetallic sulfide veins related to phyllic alteration were produced during stage 3, and ore-barren quartz ± calcite ± pyrite veins associated with weak carbonatation were produced during stage 4. C, O, and D isotope compositions of hydrothermal calcite, dolomite, magnetite, phlogopite, and quartz from different stages of mineralization during the formation of the Shangfanggou deposit range from − 12.9‰ to + 8.8‰, − 3.2‰ to + 22.7‰, and − 100‰ to − 80‰, respectively. Sulfur isotope compositions of sulfides from the ores of the Shanfanggou deposit range from 3.6‰ to 4.4‰. 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios of 17.648 to 18.742 (apart from one magnetite with a value of 20.78), 15.526 to 15.690, and 38.197 to 39.823 in the Shanfanggou deposit. The evolution of the ore-forming fluids in the Shangfanggou deposit, as revealed by δ 18 O, δD, and δ 13 C isotope studies, was one of progressive modification of the magmatic fluids through fluid–wall rock interactions along conduits during fluid ascent, and this signifies the involvement of formation/strata water during the earlier stages of mineralization, and the predominance of meteoric waters over magmatic fluids in the later stages. The carbon, sulfur, and lead isotope compositions suggest mixing took place between the magmas and the host rocks within the region. Integrating the data obtained from studies of the regional geology, ore geology, fluid inclusions, and C–H–O–S–Pb isotope geochemistry, we conclude that the Shangfanggou Mo–Fe deposit is a porphyry-skarn type system that formed during a transition from compressional to extensional tectonics during the Jurassic–Early Cretaceous continental collision between the North China Craton and Yangtze Craton. The ore materials were sourced from magmatic ore-forming fluids that mixed with components derived from carbonaceous wall rocks during their ascent, and which were gradually mixed with meteoric waters, especially in the later stages.

Au 2 Te has previously been reported as a new mineral, although without adequate mineralogical data. Examination of Au 2 Te grains from the Sandaowanzi gold deposit, utilizing optical microscope, EPMA, SEM backscattered electron, and X-ray images revealed an apparently homogeneous composition leading to its examination as a possible new mineral. However, high resolution SEM, TEM, and micro-zone XRD analyses demonstrate that the Au 2 Te phase gives a false stoichiometry and is not a new mineral species, but a mixture of native gold and calaverite with a nanographic texture that is highly comparable to that of the Turing pattern. This finding implies that the nanographic textures of Au 2 Te composed of alternating growth layers of native gold (Au) and calaverite (AuTe 2 ) are attributable to decomposition or breakdown of the previous metastable phases during cooling.

A fast and ultrasensitive indirect competitive time-resolved fluoroimmunoassay (TRFIA) was developed for the analysis of paclobutrazol in environmental water and soil samples. Paclobutrazol hapten was synthesized and conjugated to bovine serum albumin (BSA) for producing polyclonal antibodies. Under optimal conditions, the 50% inhibitory concentration (IC50 value) and limit of detection (LOD, IC20 value) were 1.09μgL(-1) and 0.067μgL(-1), respectively. The LOD of TRFIA was improved 30-fold compared to the already reported ELISA. There was almost no cross-reactivity of the antibody with the other structural analogues of triazole compounds, indicating that the antibody had high specificity. The average recoveries from spiked samples were in the range from 80.2% to 104.7% with a relative standard deviation of 1.0-9.5%. The TRFIA results for the real samples were in good agreement with that obtained by high-performance liquid chromatography analyses. The results indicate that the established TRFIA has potential application for screening paclobutrazol in environmental samples.

The large Shuangwang gold deposit (&gt, 80 t gold) is located in the Western Qinling Orogen (WQO) of central China. It is an orogenic-type gold deposit hosted in an NW-extending breccia belt in the Devonian Xinghongpu Formation. Gold mineralization of the Shuangwang deposit is featured by hydrothermal breccia ores with strata fragments cemented by hydrothermal minerals dominated by ankerite, quartz, and pyrite with minor amounts of calcite and albite. Pyrite is the major gold-hosting sulfide and the most abundant ore mineral. Crystal habits, thermoelectricity, and trace-element composition of pyrites from the main ore-forming stage of the Shuangwang gold deposit were studied by microbinocular, BHTE-06 thermoelectric coefficient measuring instrument, and high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Spatial distribution of the above data for pyrites was delineated by contour maps of morphology index, P-type frequency, and primary halo elements (e.g., supraore halo elements Ba and Sb, near-ore halo elements Pb, Zn, and Cu, and subore halo elements Co, Mo, and Bi). Based on the above results, four target areas (areas between prospecting lines 0 and 1, between lines 14 and 18 below orebody KT9, areas between prospecting lines 30 and 34, between lines 44 and 46 below orebody KT8) were put forward for deep gold exploration in the future. These targets are consistent with the depth extrapolation of proven gold orebodies, indicating the practicality of typomorphic characterization of pyrites as vector to deep/concealed gold orebodies. The effectiveness of the pyrite typomorphic parameter for deep gold prediction seems to be chemical composition, crystal habits, and then thermoelectricity.

Increased awareness of phthalic acid esters (PAEs) toxicity has given rise to a dramatic increase in concern about the determination of these contaminations in the environment. In this paper, a sensitive, selective and rapid enzyme immunoassay of ELISA based on polyclonal antibody for detecting butyl benzyl phthalate (BBP) was developed and applied in the environmental water and soil samples. The hapten of BBP was synthesized, then applied to prepare artificial antigen and produce polyclonal antibody capable of specific recognizing BBP. From the optimal standard curve of ELISA for BBP, the values of LOD (limit of detection, IC10) and IC50 were 2.5 and 79.4 ng/mL, respectively. The ELISA showed high specificity, with the cross-reactivity toward BBP analogs

In this communication, 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) funtionalized graphene nanoribbons (HP-β-CD/GNRs) were prepared for the first time by using a simple wet chemical strategy, and then, the HP-β-CD/GNRs were applied for constructing electrochemical sensors for three representative analytes (p-aminophenol, p-AP; l-tyrosine, Tyr; rhodamine B, RhB). Owing to the synergetic effects of GNRs (excellent electrochemical properties and large surface area) and HP-β-CD (high host–guest recognition and enrichment capability), the highly sensitive electrochemical sensing platforms of three analytes were established by using HP-β-CD/GNRs modified electrode, and the detection limits were 0.0008, 0.003, and 0.001 μM for p-AP, Tyr, and RhB, respectively. Keywords: Graphene nanoribbon, Cyclodextrin, Electrochemical sensor, p-Aminophenol, l-Tyrosine, Rhodamine B

An indirect competitive enzyme-linked immunosorbent assay (ELISA) for flonicamid was developed based on a polyclonal antibody. 4-Trifluoronicotinic acid (TFNA) was used as flonicamid hapten and conjugated to bovine serum albumin (BSA) to produce an immunogen and ovalbumin (OVA) to produce a coating antigen. Polyclonal antibodies against flonicamid were successfully produced by immunizing New Zealand white rabbits. Under the optimal conditions, the 50% inhibitory concentration (IC50 value) of standard curves was 7.89 mg L−1 and the limit of detection (IC10) was 0.063 mg L−1. There was almost no cross-reactivity of the antibody with three structurally related metabolites, indicating that the antibody had high specificity. The recoveries from spiked water, soil, tomato and apples were in the range of 82.4–113.4% with relative standard deviations of 2.9–10.3%. Moreover, the ELISA for spiked samples showed reliability and high correlation with gas chromatography. These results suggest that the proposed ELISA method has potential application for screening flonicamid in agricultural and environmental samples.

Microporous gold is common in many Te-Au deposits. Experimental formation and textures of microporous gold have recently been studied. However, few studies have worked on naturally occurring microporous gold. At the Dongping gold deposit, which is one of the most studied Au-Ag-Te deposits in China natural microporous gold is widely distributed in both primary and oxidized ores. This provides a good opportunity to study the textures and the formation of microporous gold in nature. This gold is pseudomorphous in addition to being porous, indicating that it formed via interface coupled dissolution-reprecipitation (ICDR) reactions. Four textures that were not described previously in experiments were observed in samples from this deposit. (1) A hackly interface between the microporous gold and parent calaverite. Te content shows a decreasing trend with increasing distance from the interface. This texture may result from diffusion of excess surface energy as the ICDR reaction moves towards equilibrium. (2) A less-porous band exists in the microporous gold. The band has fewer pores, smaller crystal sizes and similar chemical composition with the surrounding microporous gold. It likely formed due to the fluctuation of the fluid physicochemical conditions (including decreasing temperature, αO2(aq) and increasing pH) that changes the dissolution rate of calaverite. (3) Microporous gold precipitated between quartz and calaverite. As well, gaps developed between gold and remnant calaverite. This texture is derived from catalytic effects of a heterogeneous nucleation or recrystallization process. It is helpful for extraction and aqueous processing of Au-Te ores, and accounts for the phenomenon that quartz can accumulate gold in some hydrothermal gold deposits. (4) Petzite coexists with Ag-bearing microporous gold, indicating that petzite may also decompose to microporous gold under hydrothermal conditions. Calaverite could be dissolved without altered pyrite at high-temperature (>200 °C) conditions, but under weathering conditions, pyrite would be altered first. In primary ores, microporous gold coexists with pyrite and baryte, indicating that it was formed during the late-stage mineralization. In oxidized ores, microporous gold coexists with limonite and baryte, indicating it may have generated during late-stage mineralization and then altered by weathering. Hydrothermal fluids derive from late-stage mineralization may play the main role in the formation of microporous gold compared to weathering processes. This observation also leads us to reappraise the importance of hydrothermal fluids in the weathering dominated ICDR geological processes.

Owing to the harmful nature of 4-nitrochlorobenzene (4-NCB, one toxic organic pollutant) and the low cost, high sensitivity and ease of operation of electrochemical method, it is highly desirable to develop effect electrochemical sensor for the detection of 4-NCB. Herein, by partially unzipping carbon nanohorns (CNHs) via a simple wet-chemistry method, CNHs and graphene oxide (GO) (CNHs/GO) nanohybrids were produced for sensing 4-NCB with synergistic properties. While the retained CNHs offer a path for rapid electron transport, the GO sheets formed by partially unzipping CNHs provide abundant active sites, further increase in surface area as well as improved dispersibility of the CNHs/GO. Our results show that the CNHs/GO modified electrode has excellent sensitivity to 4-NCB with a wide linear response range and a detection limit as low as 10 nM.

Salbutamol (SAL) has potential hazardous effects on health, and has been found in natural water globally. To protect consumers from risks related to SAL residues, a fast and highly sensitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of SAL in environmental water samples. SAL hapten was synthesized and conjugated to proteins to be used as the immunogen for producing polyclonal antibodies. Under optimized conditions, the ELISA showed a 50% inhibitory concentration (IC50 value) of 0.466μg/L, with a limit of detection (LOD, IC10 value) of 0.021μg/L. The LOD of the ELISA was 5-fold lower than the maximum residue limits. The average recoveries of SAL from environmental samples, including tap water, river water and wastewater, ranged from 80.1 to 115.6%, which is well within the requirements of residue detection. Moreover, the results of the ELISA correlated well with high-performance liquid chromatography results, with a correlation coefficient of 0.988. These results suggest that the proposed ELISA method has potential application for the monitoring of SAL residues in environmental water samples.

The Haoyaoerhudong gabbro is a mafic intrusion located in the Haoyaoerhudong gold deposit, which is a giant gold deposit (148 t Au) hosted in Proterozoic strata on the northern margin of the North China Craton. In this paper, we present integrated SHRIMP U&ndash, Pb, geochemical and Sr&ndash, Nd isotopic data from gabbro of the Haoyaoerhudong gold deposit to reveal the magmatic processes behind its origin. SHRIMP zircon U&ndash, Pb dating constrains the timing of crystallization of the Haoyaoerhudong gabbro to 278.8 &plusmn, 0.81 Ma. Whole-rock geochemical results indicate that the Haoyaoerhudong gabbro has calc-alkaline features with enrichments of large-ion lithophile elements (LILE) and light rare-earth elements (REE) as well as depletions of high-field strength elements (HFSE). The relatively high (87Sr/86Sr)i (0.7053 to 0.7078) and low &epsilon, Nd(t) (&minus, 4.6 to &minus, 15.1) values of the gabbro indicate the involvement of crustal materials. Low Ce/Pb ratios (1.35 to 7.38), together with nearly constant La/Sm and Th/Yb ratios and variable Ba/Th and Sr/Nd ratios, suggest that the ancient mantle was modified by slab dehydration fluids. Based on new geochemical data and regional geological investigations, we propose that both the Haoyaoerhudong gold deposit and the Haoyaoerhudong gabbro formed in a post-orogenic extensional setting.

A simple and signal-amplified, label-free electrochemical impedimetric immunosensor for dibutyl phthalate (DBP), a type of phthalate ester, was developed using gold nanoparticles (AuNPs) induced signal amplification. The approach was based on an indirectly competitive binding system of coating antigen that coated on antigen/chitosan/MWCNTs@GONRs/GCE (modified electrodes), target (DBP) and anti-DBP antibody. Signal amplification was performed via the enlargement of AuNPs through NADH-promoted catalytic precipitation, which caused a marked increase in the electron-transfer resistance and electrostatic repulsion after an AuNP-labeled second antibody conjugated to anti-DBP. Under the optimized conditions, this method displayed: (i) low detection limits (7 ng/mL, 10 times lower than the traditional ELISA method using the same antibody); (ii) satisfactory accuracy (recoveries, 86.0–120.4%) and agreement with corresponding ELISA method; (iii) high tolerance to some environmental interferents; and (iv) low cost and low sample consumption (6 µL). Our results demonstrate the great potential and high efficiency of this immunosensor in practical applications for the cost-effective and sensitive monitoring of DBP in aquatic environments.

A fast and sensitive polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for the analysis of flonicamid in environmental and agricultural samples. Two haptens of flonicamid differing in spacer arm length were synthesized and conjugated to proteins to be used as immunogens for the production of polyclonal antibodies. To obtain most sensitive combination of antibody/coating antigen, two antibodies were separately screened by homologous and heterologous assays. After optimization, the flonicamid ELISA showed that the 50% inhibitory concentration (IC50 value) was 3.86mgL(-1), and the limit of detection (IC20 value) was 0.032mgL(-1). There was no cross-reactivity to similar tested compounds. The recoveries obtained after the addition of standard flonicamid to the samples, including water, soil, carrot, apple and tomato, ranged from 79.3% to 116.4%. Moreover, the results of the ELISA for the spiked samples were largely consistent with the gas chromatography (R(2)=0.9891). The data showed that the proposed ELISA is an alternative tool for rapid, sensitive and accurate monitoring of flonicamid in environmental and agricultural samples.