Hassan Mohamed Elsangedy

Excess inorganic phosphate is a leading cause of eutrophication in aquatic ecosystems, contributing to harmful algal blooms, oxygen depletion, and an overall decline in the water quality. Accurate determination of the phosphate is essential for effective water quality monitoring and environmental management. Traditional methods involve multiple reagents, incubation steps, and long assay times, making them labor-intensive and impractical for large-scale monitoring. Here, we report a simple spectroscopic assay for determining phosphate in eutrophic waters using the unique reactivity and fast proton-coupled electron transfer (PCET) kinetics of quinhydrone (QH) for phosphate. The detection mechanism, supported by density functional theory calculations, involves PCET and hydrogen bonding between QH and dihydrogen phosphate, forming a stable hydrogen-bonded complex (QH-H₂PO₄^-), triggering π → π* transitions and an immediate color change from light yellow to dark brown. The method achieves a low limit of detection (374 nM), a broad linear range (1-350 μM), and selectivity over common interferences, with a total analysis time of 30 s. When applied to phosphate measurements in eutrophic lake water, it demonstrates robust performance in excellent agreement with standard approaches while offering superior speed and simplicity. Requiring only one reagent, no incubation steps, and operating efficiently across a broad pH range (4-9), the method holds promise as an easy-to-use tool for the rapid monitoring of phosphate and nutrient pollution in water systems.

Na _2/3 [Ni _1/3 Mn _2/3 ]O ₂ (NNMO) Na-ion battery cathodes cycle well between 2 and 4 V (a) but suffer from severe decay when cycled above 4 V (b) due to P2–O2 transition. Doping strategies used to overcome this issue are discussed in this article.

An environmentally responsible synthesis of Na_2/3[Ni_1/3Mn_2/3]O₂ (NNMO) enabled by direct conversion of metallic Ni powder, releasing only O₂ and H₂O as byproducts. The resulting NNMO exhibits excellent cycling performance as a Na-ion battery cathode.

Cerium oxide nanoparticles (CeNPs) are versatile materials with unique and unusual properties that vary depending on their surface chemistry, size, shape, coating, oxidation states, crystallinity, dopant, and structural and surface defects. This review encompasses advances made over the past twenty years in the development of CeNPs and ceria-based nanostructures, the structural determinants affecting their activity, and translation of these distinct features into applications. The two oxidation states of nanosized CeNPs (Ce³⁺/Ce⁴⁺) coexisting at the nanoscale level facilitate the formation of oxygen vacancies and defect states, which confer extremely high reactivity and oxygen buffering capacity and the ability to act as catalysts for oxidation and reduction reactions. However, the method of synthesis, surface functionalization, surface coating and defects are important factors in determining their properties. This review highlights key properties of CeNPs, their synthesis, interactions, and reaction pathways and provides examples of emerging applications. Due to their unique properties, CeNPs have become quintessential candidates for catalysis, chemical mechanical planarization (CMP), sensing, biomedical applications, and environmental remediation, with tremendous potential to create novel products and translational innovations in a wide range of industries. This review highlights the timely relevance and the transformative potential of these materials in addressing societal challenges and driving technological advancements across these fields.

Metal-organic frameworks (MOFs) with intrinsic luminescent properties, modular structure, and tunable electronic properties, provide unique opportunities for designing target-specific molecular sensors by systematically choosing their constituent building blocks. We report a simple one-step MOF-based sensing platform for phosphate (P) detection that combines the luminescent properties of 2-aminoterephthalic acid (ATA) with the affinity of rationally selected nodes in UiO-66-NH₂ to bind with P. This MOF possesses an electron-donating amine group that controls the light-harvesting characteristics of the linkers. Substituting Zr₆ node with Ce₆ or Hf₆ results in a series of isostructural MOFs with distinct optical properties that are nonexistent in the unsubstituted MOF. We have utilized these MOFs to quantitatively measure P, using its ability to bind strongly to metal nodes inhibiting the LMCT process and altering the linker's photon emission. Using this system, detection limits of 4.5, 7.2 and 10.5 μM were obtained for the UiO-66-NH₂(Ce), UiO-66-NH₂, and UiO-66-NH₂(Hf) respectively, adopting a straightforward single step procedure. These results demonstrate that the selection of metal nodes in a series of isostructural MOFs can be used to modulate their electronic properties and create sensing probes possessing the desired characteristics needed for the detection of environmental contaminants.

Since the recommendations of moderate-to vigorous physical activity (PA) for health constitute important information to be shared in counseling practice, the present study was aimed to evaluate the level of knowledge of health professionals about the international PA recommendations for adults and elderly and to verify if there are associations between PA motivation with leisure time PA, readiness to change behavior and body mass index (BMI) of these professionals. In 2021, a questionnaire was applied remotely with health professionals from Brazilian health system. The survey had 34 participants, who answered sociodemographic and health questions, knowledge about international PA recommendations for adults and the elderly, PA duration, behavioral stage and motivations for PA practice. Of the five questions that assessed the knowledge of professionals, three had the highest prevalence of wrong answers, and professionals who have a more internal motivation to practice PA showed a significant association with reaching the minimum PA and eutrophic BMI recommendations. Professional qualification is important, together with encouragement to practice PA, through contents that consider internal motivations.

Nanoelectrochemistry allows for the investigation of the interaction of per‐ and polyfluoroalkyl substances (PFASs) with silver nanoparticles (AgNPs) and the elucidation of the binding behaviour of PFASs to nanoscale surfaces with high sensitivity. Mechanistic studies supported by single particle collision electrochemistry (SPCE), spectroscopic and density functional theory (DFT) calculations indicate the capability of polyfluorooctane sulfonic acid (PFOS), a representative PFAS, to selectively bind and induce aggregation of AgNPs. Single‐particle measurements provide identification of the “discrete” AgNPs agglomeration (e.g. 2–3 NPs) formed through the inter‐particles F−F interactions and the selective replacement of the citrate stabilizer by the sulfonate of the PFOS. Such interactions are characteristic only for long chain PFAS (‐SO₃⁻) providing a means to selectively identify these substances down to ppt levels. Measuring and understanding the interactions of PFAS at nanoscale surfaces are crucial for designing ultrasensitive methods for detection and for modelling and predicting their interaction in the environment.

MWCNTs composite with UiO-66-NH ₂ MOF doped with Ni( ii ) ions produced a highly efficient heterogeneous electrocatalyst for the water oxidation reaction.