Cu,Ce-containing phosphotungstates as laccase-like nanozyme for colorimetric detection of Cr(VI) and Fe(â ¢).

Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe3+ and Cr6+ could significantly enhance the electron transfer rates of Ce3+ and Ce4+, along with generous Cu2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe3+ and Cr6+ in a range of 0.667-333.33 µg/mL and 0.033-33.33 µg/mL with a low detection limit of 0.135 µg/mL and 0.0288 µg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis.

Alkyl effects on charge recombination in copper electrolyte-based dye-sensitized solar cells: Insights for targeted molecular design towards high performance.

Two quinoxaline dyes utilized in copper-electrolyte-based dye-sensitized solar cells (Cu-DSSCs) are theoretically investigated to analyze the impact of alkyl chains on dye performance. The investigation shows that ZS4, known for its record efficiency of up to 13.2 %, exhibits higher electron coupling and fewer binding sites for dye-[Cu(tmby)2]2+ interaction compared to ZS5. Contrary to common belief, alkyl chains are found to not only provide shielding but also hinder the interaction between dye and [Cu(tmby)2]2+ by influencing the optimal conformation of dyes, thereby impeding the charge recombination process. It is crucial to consider the influence of alkyl chains on dye conformation when discussing the relationship between dye structure and performance, rather than oversimplifying it as often done traditionally. Building on these findings, eight dyes are strategically designed by adjusting the position of the alkyl chain to further decrease charge recombination compared to ZS4. Theoretical evaluation of these dyes reveals that changing the alkyl chain on the nitrogen atom from 2-ethylhexyl (ZS4) to 1-hexylheptyl (D3-2) not only reduces the charge recombination rate but also enhances light harvesting ability. Therefore, D3-2 shows potential as a candidate for experimental synthesis of high-performance Cu-DSSCs with improved efficiency.

Cu/TiO2 adsorbents modified by air plasma for adsorption-oxidation of H2S.

In this study, non-thermal plasma (NTP) was employed to modify the Cu/TiO2 adsorbent to efficiently purify H2S in low-temperature and micro-oxygen environments. The effects of Cu loading amounts and atmospheres of NTP treatment on the adsorption-oxidation performance of the adsorbents were investigated. The NTP modification successfully boosted the H2S removal capacity to varying degrees, and the optimized adsorbent treated by air plasma (Cu/TiO2-Air) attained the best H2S breakthrough capacity of 113.29 mg H2S/gadsorbent, which was almost 5 times higher than that of the adsorbent without NTP modification. Further studies demonstrated that the superior performance of Cu/TiO2-Air was attributed to increased mesoporous volume, more exposure of active sites (CuO) and functional groups (amino groups and hydroxyl groups), enhanced Ti-O-Cu interaction, and the favorable ratio of active oxygen species. Additionally, the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results indicated the main reason for the deactivation was the consumption of the active components (CuO) and the agglomeration of reaction products (CuS and SO42-) occupying the active sites on the surface and the inner pores of the adsorbents.

Insight into the bimetallic structure sensibility of catalytic nitrate reduction over Pd-Cu nanocrystals.

Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater. However, the structure of bimetallic has been much less investigated for catalyst optimization. Herein, two main types of Pd-Cu bimetallic nanocrystal structures, heterostructure and intermetallic, were prepared and characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals, while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals. The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow. The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported on α-Al2O3, γ-Al2O3, SBA-15, and XC-72R exhibited 3.82-, 6.76-, 4.28-, 2.44-fold enhancements relative to the intermetallic nanocrystals, and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals, respectively. This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts, and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity, which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.

Insight into catalytic performance and reaction mechanism for toluene total oxidation over Cu-Ce supported catalyst.

Herein, three supported catalysts, CuO/Al2O3, CeO2/Al2O3, and CuO-CeO2/Al2O3, were synthesized by the convenient impregnation method to reveal the effect of CeO2 addition on catalytic performance and reaction mechanism for toluene oxidation. Compared with CuO/Al2O3, the T50 and T90 (the temperatures at 50% and 90% toluene conversion, respectively) of CuO-CeO2/Al2O3 were reduced by 33 and 39 °C, respectively. N2 adsorption-desorption experiment, XRD, SEM, EDS mapping, Raman, EPR, H2-TPR, O2-TPD, XPS, NH3-TPD, Toluene-TPD, and in-situ DRIFTS were conducted to characterize these catalysts. The excellent catalytic performance of CuO-CeO2/Al2O3 could be attributed to its strong copper-cerium interaction and high oxygen vacancies concentration. Moreover, in-situ DRIFTS proved that CuO-CeO2/Al2O3 promoted the conversion of toluene to benzoate and accelerated the deep degradation path of toluene. This work provided valuable insights into the development of efficient and economical catalysts for volatile organic compounds.

N-doped Cu2O with the tunable Cu0 and Cu+ sites for selective CO2 electrochemical reduction to ethylene.

The electrochemical carbon dioxide reduction reaction (CO2RR) to high value-added fuels or chemicals driven by the renewable energy is promising to alleviate global warming. However, the selective CO2 reduction to C2 products remains challenge. Cu-based catalyst with the specific Cu0 and Cu+ sites is important to generate C2 products. This work used nitrogen (N) to tune amounts of Cu0 and Cu+ sites in Cu2O catalysts and improve C2-product conversion. The controllable Cu0/Cu+ ratio of Cu2O catalyst from 0.16 to 15.19 was achieved by adjusting the N doping amount using NH3/Ar plasma treatment. The major theme of this work was clarifying a volcano curve of the ethylene Faraday efficiency as a function of the Cu0/Cu+ ratio. The optimal Cu0/Cu+ ratio was determined as 0.43 for selective electroreduction CO2 to ethylene. X-ray spectroscopy and density functional theory (DFT) calculations were employed to elucidate that the strong interaction between N and Cu increased the binding energy of NCu bond and stabilize Cu+, resulting in a 92.3% reduction in the potential energy change for *CO-*CO dimerization. This study is inspiring in designing high performance electrocatalysts for CO2 conversion.

A novel fluorescent probe with high sensitivity and selectivity for "On-Off-On" sensors for Cu2+ cations and CN- anions.

A novel fluorescent probe NIPF was synthesized by the Suzuki reaction to recognize Cu2+ and CN-. With the addition of Cu2+, NIPF exhibited strong fluorescence quenching (90 % for NIPF) with a Ksv value of 3.4 × 106 M-1 and a detection limit of 9.04 × 10-10 M. Subsequently, CN- was added to the NIPF-Cu2+ solution, and [Cu(CN)x]n- was formed due to the strong interaction between Cu2+ and CN- leading to fluorescence recovery (89 % for NIPF-Cu2+). In addition, a detection limit of 3.6 × 10-8 M was obtained by fluorescence titration. Meanwhile, it was demonstrated that the sensor achieved 93 %-105 % recovery of Cu2+ in the tested environmental samples, and the practicability of Cu2+ and CN- detection were verified using hydrogels test, with significant color changes observed under 365 nm light. Accordingly, the fluorescent probe NIPF was used to recognize Cu2+ and CN- by the "on-off-on" sensors.

Theoretical Optimization of an Earth-Abundant and Environmentally Friendly Photovoltaic Absorber Cu3PSe4 from First-Principles Study to Device Simulation.

To seek an earth-abundant and environmentally friendly absorber for thin-film solar cells, Cu3PSe4 is investigated by first-principles calculations and device simulations. We demonstrate that the compound has a suitable band gap width of 1.3 eV as well as a high sunlight absorption coefficient. However, drawbacks like small electron affinity, high hole concentration, large lattice mismatch with CdS, etc., are revealed, which may degrade the photovoltaic performance. To address those shortcomings, we propose (1) to optimize the carrier concentration by preparing the samples at low temperature and under a Cu-rich environment, (2) to replace the CdS buffer layer by a more suitable wide-gap semiconductor with smaller lattice mismatch, and (3) that the selected buffer layer should have small electron affinity in order to reduce the open-circuit voltage losses. After implementation of these optimization approaches, the device simulations demonstrate that the power conversion efficiency reaches 17.7% for a solar cell with the configuration Mo/Cu3PSe4/WS2/n-ZnO. The combination of first-principles calculations at the atomistic level and device simulations at the macroscopic level provides an appropriate approach to design ideal solar cells.

A comprehensive review on the development of chiral Cu, Ni, and Zn complexes as pharmaceutical agents over the past decades: Synthesis, molecular structure and biological activity.

Chirality is a fundamental and widespread geometric structural property in living organisms that most biomacromolecules including nucleic acids, proteins and enzymes, possess. Consequently, the development of chiral drugs capable of binding specific targets have gradually gained wide attention in recent decades due to their selective effects on a broad spectrum of biological events ranging from cell metabolism to cell fate. In this context, the synthesis of chiral compounds as promising therapeutic candidates has assumed a major role in drug discovery. Among them, chiral metal complexes have attracted considerable interest due to their unique and intriguing structural features that could enable overcoming side effects and drug-resistance phenomena of metal-based drugs currently in the market such as cisplatin. In the current scenario, an in-depth overview of non-platinum chiral complexes needs to be presented and carried forward. Therefore, in this perspective article, an update of the scientific development of bioactive chiral copper, zinc and nickel complexes have been reported since they have not been thoroughly reviewed so far. Specifically, we focused the article mainly on metal complexes containing chiral ligands (type 2 chirality) as in literature they are more numerous than those with chirality at the metal center (type 1 chirality). Herein, not only their biological activity but also their mechanism of action is summarized. Furthermore, in the final section of the article we have highlighted copper-based complexes as those with a superior biological activity profile and greater prospects for development as a drug.

Magnetic nanoparticle-decorated metal organic frameworks for chemiluminescence detection of glutathione.

A chemiluminescence (CL) method for determination of glutathione (GSH) was developed with magnetic nanoparticle-decorated metal organic frameworks (Fe3O4 NPs@Cu-TATB). The composite material was synthesized via a hydrothermal method and glutathione (GSH) can be detected by both visual and chemiluminescence (CL) methods. The synthesized Fe3O4 NPs@Cu-TATB exhibited excellent catalytic activity in the luminol-H2O2 CL system. The mechanism revealed that three types of oxygen-containing radicals (ROS) were generated in this system. As GSH can reduce the catalytic effect of generated ROS radicals, the inhibiting CL signal was produced in the Fe3O4 NPs@Cu-TATB-luminol-H2O2 system. Based on the established CL system, the detection limits for GSH using CL and visual methods were found to be 0.3 µM and 0.7 µM, respectively. This low-cost and convenient detection method can be applied to the determination of GSH content in human blood.

Optical Chemosensor as a Sensitive and Selective Tool for the Detection of Thiocyanate Ions Via Cu2+ Induced Sensor and Its Practical Application.

In various fields, including analytical, environmental, and biochemistry, the detection of ions is significant. A simple probe, 3-(1-((4-aminophenyl)imino)ethyl)-4-hydroxy-6-methyl-2H-pyran-2-one (DPD), was designed for this study and used for the detection of Cu2+ ions in methanol, based on dehydroacetic acid and phenylenediamine moieties. Binding interactions studies were performed using UV-Vis measurements, which showed selective binding behaviour towards Cu2+ ions. The HRMS spectral data and Job's plot were used to check the stoichiometry ratio of 2:1 of a probe to Cu2+ ions. A detection limit of 1.38×10-7 M for Cu2+ ions was observed. Theoretical DFT calculations were used to determine the quantum parameters and the energy gap between frontier molecular orbitals. Interestingly, the DPD-Cu2+ complex acted as a probe for the detection of SCN- ions at a low LOD value, i.e., 1.97×10-7 M. A novel incidence of reversibility with SCN- ions was reported using the HRMS technique. Next, real water and blood samples were used, and the concentration of Cu2+ ions was calculated to further analyse the practical applicability of the probe. The DPD probe showed better selectivity and sensitivity than previously reported sensors, especially in complex matrices, where other sensors frequently experience interference and detection limit issues, indicating its potential as an advanced tool for ion detection in various applications.

Altered copper transport in oxidative stress-dependent brain endothelial barrier dysfunction associated with Alzheimer's disease.

Oxidative stress and blood-brain barrier (BBB) disruption due to brain endothelial barrier dysfunction contribute to Alzheimer's Disease (AD), which is characterized by beta-amyloid (Aß) accumulation in senile plaques. Copper (Cu) is implicated in AD pathology and its levels are tightly controlled by several Cu transport proteins. However, their expression and role in AD, particularly in relation to brain endothelial barrier function remains unclear. In this study, we examined the expression of Cu transport proteins in the brains of AD mouse models as well as their involvement in Aß42-induced brain endothelial barrier dysfunction. We found that the Cu uptake transporter CTR1 was upregulated, while the Cu exporter ATP7A was downregulated in the hippocampus of AD mouse models and in Aß42-treated human brain microvascular endothelial cells (hBMECs). In the 5xFAD AD mouse model, Cu levels (assessed by ICP-MS) were elevated in the hippocampus. Moreover, in cultured hBMECs, Aß42-induced reactive oxygen species (ROS) production, ROS-dependent loss in barrier function (measured by transendothelial electrical resistance), and tyrosine phosphorylation of CDH5 were all inhibited by either a membrane permeable Cu chelator or by knocking down CTR1 expression. These findings suggest that dysregulated expression of Cu transport proteins may lead to intracellular Cu accumulation in the AD brain, and that Aß42 promotes ROS-dependent brain endothelial barrier dysfunction and CDH5 phosphorylation in a CTR1-Cu-dependent manner. Our study uncovers the critical role of Cu transport proteins in oxidative stress-related loss of BBB integrity in AD.

Enhanced Thermoelectric Performance of p-type AgSbTe2 via Cu Doping.

Recently, the p-type semiconductor AgSbTe2 has received a great deal of attention due to its promising thermoelectric performance in intermediate temperatures (300-700 K). However, its performance is limited by the suboptimal carrier concentration and the presence of Ag2Te impurities. Herein, we synthesized AgSb1-xCuxTe2 (x = 0, 0.02, 0.04, and 0.06) and investigated the effect of Cu doping on the thermoelectric properties of AgSbTe2. Our results indicate that Cu doping suppresses the Ag2Te impurities, raises the carrier concentration, and results in an improved power factor (PF). The calculation reveals that Cu doping downshifts the Fermi energy level, reduces the energy band gap and the difference among several valence band maximums, and thereby explains the improvement of PF. In addition, Cu doping reduces the thermal conductivity, possibly attributed to the inhibition of Ag2Te impurities and the phonon softening of the AgSb1-xCuxTe2. Overall, Cu doping improves the ZT of AgSb1-xCuxTe2. Among all samples, AgSb0.96Cu0.04Te2 has a maximum ZT of ∼1.45 at 498 K and an average ZT of ∼1.11 from 298 to 573 K.

Near-Electrode Concentration Gradients of Bicarbonate and pH within Porous Gas Diffusion Electrode for Optimized Selective CO2 Electroreduction to C2+ Products.

With high current density, the intense near-electrode CO2 reduction reaction (CO2RR) will cause the concentration gradients of bicarbonate (HCO3-) and hydroxyl (OH-) ions, which affect the selectivity of high-value C2+ products of the CO2RR. In this work, we simulated the near-electrode concentration gradients of electrolyte species with different porous Cu-based CLs (catalyst layers) of GDE (gas diffusion electrode) by COMSOL Multiphysics. The higher porosity CL exhibits a better buffer ability of local alkalinity while ensuring a sufficient supply of H+ and local CO2 concentration. Subsequently, the different porosity CLs were prepared by vacuum-thermal evaporation with different evaporation rate. Structural characterizations and liquid permeability tests confirm the role of the porous CL structure in optimizing concentration gradients. As a result, the high-porosity CL (Cu-HP) exhibits a higher C2+ Faraday efficiency (FE) of ∼79.61% at 500 mA cm-2 under 1 M KHCO3, far more than the FEC2+ ≈ 38.20% with the low-porosity sample (Cu-LP).

Recent progress of methods for cuproptosis detection.

Varying from other identified cell death pathways, cuproptosis is a new type of regulated cell death characterized by excess Cu ions, abnormal aggregation of lipoylated proteins in TCA cycle, loss of Fe-S cluster proteins, upregulation of HSP70, leading to proteotoxic and oxidative stress. Cuproptosis is highly concerned by scientific community and as the field of cuproptosis further develops, remarkable progress has been made in the verification and mechanism of cuproptosis, and methods used to detect cuproptosis have been continuously improved. According to the characteristic changes of cuproptosis, techniques based on cell death verification, Cu content, morphology, molecular biology of protein levels of cuproptosis-related molecules and biochemical pathways of cuproptosis-related enzyme activity and metabolites of oxidative stress, lipoic acid, TCA cycle, Fe-S cluster proteins, oxidative phosphorylation, cell respiration intensity have been subject to cuproptosis verification and research. In order to further deepen the understanding of detecting cuproptosis, the principle and application of common cuproptosis detection methods are reviewed and categorized in cellular phenomena and molecular mechanism in terms of cell death, Cu content, morphology, molecular biology, biochemical pathways with a flow chart. All the indicating results have been displayed in response to the markers of cuproptosis, their advantages and limitations are summaried, and comparison of cuproptosis and ferroptosis detection is performed in this study. Our collection of methods for cuproptosis detection will provide a great basis for cuproptosis verification and research in the future.

Fe, Cu dual-atom catalysts assisted molecularly imprinted electrochemiluminescence sensor for ultrasensitive detection of trichlorfon.

Trichlorfon (TCF) has the possibility of contaminating agricultural crops and posing some health risks to humans. Herein, an electrochemiluminescence (ECL) sensor based on Fe, Cu dual-atom catalysts (Fe/Cu-N-C DACs) and Au@Luminol was developed for the ultrasensitive detection of TCF. Fe/Cu-N-C with diatomic sites has a very high catalytic activity and can be used as a co-reaction accelerator to activate H2O2 to generate a large number of hydroxyl radicals which triggered a strong cathodic ECL signal of luminol. TCF molecularly imprinted polymer (MIP) was further introduced as a specific recognition element, and the interaction between the template molecule and the functional monomer was verified by molecular docking technique. The developed sensing platform was successfully applied to the ultrasensitive detection of TCF with a linear range from 1.0 pg/mL to 5.0 µg/mL with a low detection limit (0.39 pg/mL). This study broadens the application of DACs in ECL sensing.

Enhancement of peroxymonosulfate activation with nickel foam-supported CuCo2O4 for tetracycline degradation: Performance and mechanism insights.

The modulation of bimetallic oxide structures and development of efficient, easily recoverable catalysts are expected to effectively overcome the limitations associated with powdered catalysts in activating peroxymonosulfate (PMS). In this study, CuCo2O4 was successfully immobilized on the surface of nickel foam (NF) via an electrodeposition-calcination procedure, with highly efficient activation of PMS for tetracycline (TC) degradation (0.55 min-1). Besides acting as a support carrier and providing ample active sites, NF mediated electron transport, prevented the leaching of metal ions and enhanced the efficiency of recycling. Density functional theory (DFT) calculations and experimental tests illustrated that Cu/Co dual-sites can efficiently adsorb PMS, enabling simultaneous reduction and oxidation reactions. The dual-site synergy substantially decreased the adsorption barrier and increased the electron transfer rate. Especially, the Cu+/Cu2+ redox couple acted as an electron donor and facilitated rapid charge transfer, leading to the conversion of Co3+ to Co2+. Moreover, the CuCo2O4@NF + PMS system effectively eliminated TC by employing radical pathways (SO4•-, •OH) and nonradical processes (1O2, e-). Therefore, this study introduces a new approach to overcome the limitations of powdered bimetallic oxides, providing a promising solution for practical applications.

A dual-response ratiometric near-infrared fluorescence probe based on cyanine platform for Cu2+ detection and its imaging in vitro and vivo.

A near-infrared fluorescent probe (NUST-Cy-1) was disclosed here, which displays ratiometric and dual-channel response for Cu2+ (λex1 = 450 nm, λex2 = 750 nm) with large Stokes shifts (143 nm, 375 nm, 75 nm respectively). This probe demonstrates high sensitivity with low detection limit (1.4 µM) and selectivity for Cu2+ detection. Furthermore, fluorescent imaging of Cu2+ in vitro and vivo were successfully achieved.

Antibacterial effect of Cu2O/TiO2 visible-light photocatalytic composite on Xanthomonas campestris.

In this study, a Cu2O/TiO2 visible light photocatalytic composite (CuTi) was employed for the treatment of Xanthomonas campestris and Xanthomonas campestris-infected Brassica napus seedlings. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against X. campestris were determined to be 8 µg ml⁻¹ and 32 µg ml⁻¹, respectively. Transmission electron microscopy analysis demonstrated a direct correlation between the extent of bacterial cell damage and the concentration of CuTi. Noteworthily, a bactericidal rate of 100% was achieved at a concentration of 150 µg·ml⁻¹ over a treatment duration of 120 min. Moreover, alterations in active oxidants and antioxidants, including ROS, GSH, GR, SOD, POD, and CAT within the bacterial cells, were examined to elucidate the underlying mechanism of inhibition by the CuTi. The Brassica napus infected by X. campestris was treated with CuTi, and the efficacy was validated through determination of plant resistance indexes. The combined data confirmed that the CuTi is characterized by a low dose, fast onset, good effect and higher safety for killing X. campestris, and it is expected to be developed as an antimicrobial agent for vegetables.

Sudden death due to aortic rupture in New Zealand sheep.

CASE HISTORY: Over a period of 2 months in the spring and early summer of 2021, 13 cases of sudden death in cull ewes due to aortic rupture were diagnosed at a small number of New Zealand abattoirs. CLINICAL FINDINGS: In 12/13 (92%) cases, a large blood clot was present in the thorax, and in one case the blood clot was seen in the tissues dorsal to the heart. There were no obvious signs of external trauma. The pluck (heart and lungs) or fixed aorta was submitted for histological examination in seven cases and in all of these, a tear in the aorta was found. Comparing the microscopic appearance of the proximal aorta in these seven cases to three clinically normal ewes from unaffected farms, the aortic wall thickness appeared thinner in the case ewes than the unaffected ewes. Subjectively, there was increased collagen in the tunica media in 3/7 and decreased elastin fibres in 5/7 case ewes compared to the control ewes. Further investigations on the index farm (where the first cases originated), found that the mean liver and serum Cu concentrations in 10 similarly aged, clinically normal ewes were within the normal reference range for New Zealand sheep. Similarly, the liver Cu concentrations of the seven case ewes were within the normal reference range. DIAGNOSIS: Aortic rupture due to an unknown aetiology. CLINICAL RELEVANCE: Clinicians should be aware of this condition as a differential diagnosis for sudden death in older sheep and to assist the Ministry for Primary Industries in establishing the extent of this problem in New Zealand.