Search Results (117)

The windowpane oyster (Placuna placenta) is common in coastal areas of the Philippines, thriving in brackish waters. Its shells underpin the local craft industries. While its meat is edible, only small amounts are consumed locally, most going to waste. Utilization of this potential nutrient source is hindered by the lack of information concerning its organic and mineral content, the possible presence of heavy metal ions, and the risk of microbial pathogens. We report extensive analysis of the meat from Placuna placenta, harvested during three different seasons to account for potential variations. This comprises proximate analysis, mineral, antioxidant, and microbial analyses. While considerable seasonal variation was observed, the windowpane oyster was found to be a rich source of protein, fats, minerals, and carbohydrates, comparing well with the meats of other shellfish and land animals. Following pre-cooking (~90 °C, 25–30 min), the standard local method for food preparation, no viable E. coli or Salmonella sp. were detected. Mineral content was broadly similar to that reported in fish, although iron, zinc, and copper were more highly represented, nevertheless, heavy metals were below internationally acceptable levels, with the exception of one of three samples, which was slightly above the only current standard, FSANZ. Whether the arsenic was in the safer organic form, which is commonly the case for shellfish, or the more toxic inorganic form remains to be established. This and the variation of arsenic over time will need to be considered when developing food products. Overall, the meat of the windowpane oyster is a valuable food resource and its current (albeit low-level) use should lower any barriers to its acceptance, making it suitable for commercialization. The present data support its development for high-value food products in urban markets. Full article

Planar heaters are designed to deliver uniform heat across broad surfaces and serve as critical components in applications requiring energy efficiency, safety, and mechanical flexibility, such as wearable electronics and smart textiles. However, conventional metal-based heaters are limited by poor adaptability to curved or complex surfaces, low mechanical compliance, and susceptibility to oxidation-induced degradation. To overcome these challenges, we applied a protein-assisted electroless copper (Cu) plating strategy to electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber substrates to fabricate flexible, conductive planar heating membranes. For interfacial functionalization, a protein-based engineering approach using bovine serum albumin (BSA) was employed to facilitate palladium ion coordination and seed formation. The resulting membrane exhibited a dense, continuous Cu coating, low sheet resistance, excellent durability under mechanical deformation, and stable heating performance at low voltages. These results demonstrate that the BSA-assisted strategy can be effectively extended to complex three-dimensional fibrous membranes, supporting its scalability and practical potential for next-generation conformal and wearable planar heaters. Full article

Annually, more than 10,000 synthetic dyes are produced worldwide, generating around 280,000 tons of waste, posing risks to human and aquatic life, and potentially creating even more toxic products than the dyes themselves. This study aims to immobilize organic dyes, forming hybrid pigments using ZnO as support obtained through starch combustion. ZnO was obtained by starch (sago) combustion and characterized by XRD, SEM and the BET method. It was then used for the adsorption of orange and green textile dyes, evaluating the adsorbent dosage, initial dye concentration, contact time, and selectivity with copper ions. The removal studies indicated up to 100% removal of both dyes at low concentrations. The co-adsorption system showed excellent performance, with removal percentages exceeding 90% for both textile dyes and Cu (II) ions. Hybrid pigments were assessed for solvent resistance and durability under extended white light exposure. ZnO immobilized the dyes, showing resistance to organic solvents and good stability under prolonged white light exposure. Full article

Saffron spice is obtained from the flower’s stigmas through a labor-intensive process. However, other organs (particularly the leaves and tepals) are often regarded as waste. To investigate the health benefits of saffron leaf by-products, an optimized methodology was developed to obtain a phenol-enriched fraction. The main components of this fraction were identified by HPLC-DAD/ESI-MS and the antiproliferative and metal-chelating effects on colon cancer cells (Caco-2) and Fe²⁺ and Cu²⁺ ions, respectively, were evaluated. The process involved the extraction of saffron leaves with a 70% hydroalcoholic solution, followed by purification using liquid chromatography. Chemical characterization revealed the presence of several phenolic compounds, including flavonoids (kaempferol, luteolin and quercetin glycosides) as major constituents; whereas, in vitro assays revealed a strong dose-dependent inhibition of cell proliferation. Likewise, the sample exhibited significant iron- and copper-chelating activity, suggesting its potential as a natural chelator to help mitigate the carcinogenic effects of metal accumulation in humans. In summary, this study underscores the potential of the saffron leaf fraction as a promising natural and complementary chemoprotective agent in colorectal cancer. Additionally, these results underscore the value of agricultural by-products, supporting a circular bioeconomy by reducing environmental impact and promoting the sustainable use of natural resources. Full article

Cu-based layered double hydroxides (LDH) have been extensively employed as catalyst precursors. However, due to the Jahn–Teller effect of copper ions, it is a challenge to synthesize well-crystallized LDH with a high Cu content, which usually contains considerable CuO impurity. By adding competitive ligands during the coprecipitation process, such as glycine, a well-crystallized Cu-rich LDH with less CuO impurity was successfully synthesized. The Cu-Mg-Al mixed oxides derived from the well-crystallized Cu-rich LDH have relatively high S_BET, large pore volume, and well dispersion of Cu nanoparticles. The derived catalyst exhibited unexpectedly high catalytic activity in the water–gas shift (WGS) reaction, and the mass-specific reaction rate was reached as high as 33.5 μmol_CO${·\mathrm{g}}_{\mathrm{cat}}^{-1}$·s⁻¹ at 200 °C. The high catalytic activity of this catalyst may originate from the high S_BET and well dispersion of Cu particles and metal oxides. Moreover, the derived catalyst also displayed outstanding long-term stability in the WGS reaction, which should benefit from the enhanced metal–support interaction. Full article

The chemical interaction of salicylic acid, formaldehyde, and sulfuric acid produced a disalicylic ligand (3,3′-dicarboxy-2,2′-dihydroxydiphenylmethane, DCM), which was then allowed to coordinate with copper (II) ions. The solid compounds’ chemical structures were determined using elemental analysis, UV-Vis, FT-IR, MS, ¹H-NMR, PXRD, SEM, TEM, magnetic studies, as well as molecular modeling based on DFT (density functional theory) calculations. It was proposed that the ligand coordinates in a tetradentate fashion with the copper ion to give a square-planar binuclear complex. A significant difference in the diffraction patterns between Cu(II)–DCM (amorphous) and DCM (crystalline) was displayed using an X-ray diffraction analysis. Spherical granules were identified throughout through morphology analysis using SEM and TEM. UV-Vis spectra were used to quantify the optical characteristics such as the energy gap, optical conductivity, refractive index, and penetration depth. The band gap values that lie within the semiconductor region suggested that the compounds could be used for electronic applications. The optimized structure of the synthesized Cu(II)–DCM complex was investigated using DFT and TD-DFT (time-dependent density functional theory) at the B3LYP/6-31G(d, p) level, with the LANL2DZ basis set for Cu in an ethanol solvent and the gas environment modeled by CPCM. The experimental data suggest a square-planar geometry of the Cu(II) binuclear complex. The theoretical calculations support the proposed structure of the compound. The cytotoxicity of the DCM against HCT–116 (human colon cancer) cells was tested, and the outcome exhibited good inhibitions of growth. A molecular docking (MD) examination was carried out to illustrate the binding mode/affinity of the prepared compounds (DCM and Cu(II)–DCM) in the active site of the receptor protein [CDK2 enzyme, PDB ID: 6GUE]. The compounds formed hydrogen bonds with the amino acid residues of the protein, increasing the binding affinity from −7.2 to −9.3 kcal/mol through the coordination process. The information from this current study, particularly the copper complex, is beneficial for exploring new compounds that have anticancer potential. Full article

Acid mine drainage (AMD) is one of the main environmental problems in mining operations. The objective of this study was to assess AMD obtained from a copper mine via toxicity identification evaluation (TIE) using Daphnia magna and Chlorella vulgaris as indicator organisms. AMD was fractionated via filtration and aeration at pH 3 and 11, activated carbon, cation resin, anion resin, and ethylenediaminetetraacetic acid (EDTA). The results showed that unfractionated AMD has a low organic matter content (total chemical organic demand, COD_T-183.05 mg/L), low pH (3.9), and high sulfates concentrations (2900 mg/L) and metal ions in solution (0.2–418.9 mg/L), producing high toxicity to Daphnia magna (0.00016% v/v) and no observable acute toxicity to Chlorella vulgaris (72 h-RFU 64.9%). For Daphnia magna, TIE fractionations with the greatest reduction in acute toxicity (LC₅₀) were filtration/pH11 (non-toxic) and anion resin (LC₅₀ = 0.43% v/v), with toxicity reduction percentages of 100% and 99%, respectively. Because of this, Cu was determined to be the main cause of acute toxicity to Daphnia magna. For Chlorella vulgaris, the activated carbon fraction stands out, increasing the % relative fluorescence units by 4% from 48 h to 72 h, demonstrating tolerance to AMD. The TIE technique is presented as an effective strategy to identify toxic compounds in complex samples and evaluate their effect on environmentally relevant organisms. Therefore, this study allows the analysis of the ecological risk in aquatic environments affected by mining activities, which supports environmental decision-making and the design of efficient treatment strategies. Full article

Alumina is a well-known catalyst and catalyst support. The electrochemical properties of alumina have recently gained attention. The electrochemical response of alumina greatly depends on the type and number of surface groups present in different alumina types. The surfaces of two types of alumina, anhydrous (A) and trihydrate (T) alumina, were modified by copper through an ion-exchange procedure. The samples were characterized by diffuse reflectance UV–Vis spectroscopy. The obtained samples were used as modifiers of carbon paste electrodes. The electrochemical characterization of the samples was performed using cyclic voltammetry and two redox probes. The electrochemical behavior of samples was investigated in the alkaline and neutral media. The electroanalytical performance of the synthesized composites was tested on glutamate and hydrogen peroxide by linear sweep voltammetry. The functionalization of alumina with copper by ion exchange offered a fast and cost-effective procedure for obtaining a composite with enhanced electrochemical properties for sensing biologically important analytes. Full article

In China, soil contamination by heavy metals is a widespread issue, with substantial increases in lead(Pb), cadmium(Cd), copper(Cu), and zinc(Zn) levels observed across various regions. Particularly, the concentrations of Pb and Cd significantly exceed their natural background levels. P-ATPases, a group of proteins, utilize energy from ATP hydrolysis to support the transmembrane movement of metal ions. This group encompasses several Heavy Metal Associated Transporter (HMA) ATPases. Studies on hyperaccumulators have shown the critical role of HMAs in the movement and reduction in Zn and Cd toxicity in plant systems. This research identifies a protein encoded by the SpHMA gene from Sedum plumbizincicola, a species noted for aiding Zn/Cd hyperaccumulators, which enhances tolerance to Cd and Zn. We detail a protein encoded by SpH/A within the HMA family that enhances Cd tolerance. Real-time fluorescence quantification (RT-PCR) indicates that SpHMA3 expression in Arabidopsis thaliana and Zea mays KN5585 correlates with high Cd tolerance, linked to Cd accumulation in Zea mays. In addition, homozygous Arabidopsis thaliana AtHMA3 mutants exhibited increased Cd sensitivity compared to the wild type (WT). Notably, plants of Arabidopsis thaliana and maize overexpressing SpHMA3 showed enhanced Cd stress tolerance compared to WT. Enhanced Cd accumulation in tissues was observed when SpHMA3 was overexpressed, as revealed by subcellular distribution analysis. We propose that SpHMA3 augments maize tolerance to Cd and Zn stresses through enhanced cellular uptake and translocation of Cd ions. This investigation clarifies the gene function of SpHMA3 in Cd and Zn stress response, offering insights for enhancing heavy metal absorption traits in maize varieties and phytoremediation methods for soils contaminated with heavy metals. Full article

With the increasing demand for air pollution control, the development of efficient and stable catalysts to degrade hazardous VOCs such as toluene has become particularly important. Herein, various copper-doped attapulgite-supported cobalt oxide spinel composites (Cu_xCo_3−xO₄/ATP) were synthesized using an ultrasonic-assisted precipitation method. The results showed that the abundant Si-OH groups on the surface of ATP played a crucial role in anchoring Co, and the instantaneous high-energy input of ultrasonication facilitated the formation of Si-O-Co bonds in Co₃O₄/ATP. The doping of Cu ions induced the expansion of the Co₃O₄ lattice, resulting in a significant number of oxygen vacancies. The ultrasound-induced synthesized Cu_0.1Co_2.9O₄/ATP catalyst exhibited the best catalytic oxidation performance, achieving a 99% toluene degradation rate at 300 °C under a weight hourly space velocity (WHSV) of 10,000 mL·g⁻¹ h⁻¹ and initial toluene concentration of 1000 ppm, along with high stability during 12 h of continuous running. This work presents a new strategy for the cost-effective catalytic elimination of VOCs. Full article

Heavy metal pollution has become an increasingly serious environmental issue, making the detection of heavy metals essential for safeguarding public health and the environment. This review aims to highlight the commonly used methods for detecting heavy metals (such as atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), inductively coupled plasma–mass spectrometry (ICP-MS), square-wave anodic stripping voltammetry (SWASV), etc.), with a particular focus on electrochemical detection and electrode modification materials. Metal nanomaterials (such as titanium dioxide (TiO₂), copper oxide (CuO), ZIF-8, MXene, etc.) are emphasized as promising candidates for enhancing the performance of sensors due to their high surface area and excellent catalytic properties. However, challenges such as interference from non-target heavy metal ions and the formation of organometallic complexes with organic compounds can complicate the detection process. To address these issues, two potential solutions have been proposed: the development of advanced algorithms (such as machine learning (ML), back-propagation neural network (BPNN), support vector machines (SVM), random forests (RF), etc.) for signal processing and the use of pretreatment methods (such as Fenton oxidation (FO), ozone oxidation, and photochemical oxidation) to suppress such interferences. This paper aims to review commonly used methods for detecting heavy metals, with a particular emphasis on electrochemical techniques. It will also highlight the challenges faced in these methods, such as interference and sensitivity limitations, and propose innovative solutions, including the use of metal nanomaterials for improved sensor performance and the integration of advanced algorithms and pretreatment techniques to address interference and enhance detection accuracy. Full article

The contamination of water by heavy metals poses an escalating risk to human health and the environment, underscoring the critical need for efficient removal methods to secure safe water resources. This study evaluated the performance of four cationic exchange materials (labeled “PS—DVB”, “PA—DVB”, “TFSA”, and “OGL”) in removing or harvesting metals such as copper, silver, lead, cobalt, and nickel from aqueous solutions, several of which are precious and/or classified as Critical Raw Materials (CRMs) due to their economic importance and supply risk. The objective was to screen and benchmark the four ion exchange materials for water treatment applications by investigating their metal sequestration capacities. Experiments were conducted using synthetic solutions with controlled metal concentrations, analyzed through ICP-OES, and supported by kinetic modeling. The adsorption capacities (qe) obtained experimentally were compared with those predicted by pseudo-first-order and pseudo-second-order models. This methodology enables high precision and reproducibility, validating its applicability for assessing ion exchange performance. The results indicated that PS—DVB and PA—DVB resins proved to be of “wide range”, exhibiting high efficacy for most of the metals tested, including CRM-designated ones, and suggesting their suitability for water purification. Additionally, the second-life Nafion-based “TFSA” material demonstrated commendable performance, highlighting its potential as a viable and technologically advanced alternative in water treatment. Lastly, the lignin-based material, “OGL”, representing the most innovative and sustainability apt option, offered relevant performance only in selected cases. The significant differences in performance among the resins underscore the impact of structural and compositional factors on adsorption efficiency. This study offers valuable insights for investigating and selecting new sustainable materials for treating contaminated water, opening new pathways for targeted and optimized solutions in environmental remediation. Full article

Pregnancy increases the demand for essential metal ions to support fetal development, making the maternal metal ion status a critical determinant of perinatal outcomes. This prospective cohort study examined changes in metal ion levels across the three trimesters, evaluated the influence of preexisting metabolic conditions on the metal ion status, and assessed the associations between maternal metal ion levels and perinatal outcomes in 206 pregnant women from the Biochemical and Epigenetic Origin of Overweight and Obesity (OBESO) cohort receiving care at the Instituto Nacional de Perinatología in Mexico City from 2017 to 2020. Six essential metal ions (iron, zinc, copper, calcium, magnesium, and phosphorus) were measured in blood samples using inductively coupled plasma optic emission spectrometry. Significant variations in the metal ion levels were observed across the trimesters, with notable decreases in iron and magnesium and increases in copper as pregnancies progressed. Maternal hypothyroidism was associated with significantly low levels of zinc and magnesium during pregnancy. Regression analyses revealed robust associations between maternal metal ion levels and perinatal outcomes. For instance, declining magnesium levels as pregnancies progressed were positively associated with gestational diabetes (OR: 2.92, p = 0.04; OR: 2.72, p = 0.03). The maternal metal ion status significantly influences perinatal outcomes. Full article

Efficient wastewater treatment, particularly the removal of heavy metal ions, remains a challenging priority in environmental remediation. This study introduces a novel sandwich-structured nanocomposite, RGO-CuS-PPy, composed of reduced graphene oxide (RGO), copper sulfide (CuS), and polypyrrole (PPy), synthesized via a straightforward hydrothermal method. The unique combination of RGO, CuS, and PPy offers enhanced adsorption capacity for Ni(II) ions due to RGO’s high surface area and CuS’s active binding sites, supported by PPy’s structural stability contributions. This study is among the first to explore this specific nanocomposite architecture for Ni(II) removal, achieving an adsorption capacity of 166.67 mg/g and a high removal efficiency of 94.9% within 210 min for 55 mg/L of Ni(II) concentration at pH 6 and adsorbent dose of 3 mg/15 mL. The kinetic analysis shows the best fitted time-dependent experimental data with the pseudo-second-order model, indicating chemisorption. Isotherm studies confirmed the Langmuir model as the best fit, yielding a high monolayer adsorption capacity of 166.67 mg/g. Thermodynamic analysis shows the adsorption process was endothermic (ΔH° = 80.23 kJ/mol) and spontaneous (ΔG° ranging from −6.985 to −14.399 kJ/mol). Additionally, reusability tests using 0.1 M HCl for desorption demonstrated good reusability, emphasizing the RGO-CuS-PPy nanocomposite’s potential as a sustainable adsorbent for Ni(II) removal in wastewater treatment applications. Full article

2-Mercaptomethylbenzo[d]imidazole (2-MMBI) derivatives were designed and synthesized as tyrosinase (TYR) chelators using 2-mercaptomethylimidazole scaffolds. Seven of the ten 2-MMBI derivatives exhibited stronger inhibition of mushroom TYR activity than kojic acid. Their ability to chelate copper ions was demonstrated through experiments using the copper chelator pyrocatechol violet and assays measuring TYR activity in the presence or absence of exogenous CuSO₄. The inhibition mechanisms of derivatives 1, 3, 8, and 9, which showed excellent TYR inhibitory activity, were elucidated through kinetic studies and supported by the docking simulation results. Derivatives 3, 7, 8, and 10 significantly inhibited cellular TYR activity and melanin production in B16F10 cells in a dose-dependent manner, with stronger potency than kojic acid. Furthermore, in situ, derivatives 7 and 10 showed stronger inhibitory effects on B16F10 cell TYR activity than kojic acid. Six derivatives, including 8, showed highly potent depigmentation in zebrafish larvae, outpacing kojic acid even at 200–670 times lower concentrations. Additionally, all derivatives could scavenge for reactive oxygen species without causing cytotoxicity in epidermal cells. These results suggested that 2-MMBI derivatives are promising anti-melanogenic agents. Full article