Rasha Abdel Baseer

The simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is crucial for biomedical and clinical diagnostics. Herein, we present a highly sensitive and selective electrochemical sensor based on a modified glassy carbon electrode (GCE) functionalized with hydroxypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), and 3D reduced graphene oxide/pentaerythritol (3D rGO/PE). The structural and morphological properties of the composite were characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Electrochemical analysis demonstrated the remarkable electrocatalytic activity of 3D rGO/PE/PVP@HPMC/GCE for the oxidation of AA, DA, and UA, with peak potential separations of 214, 133, and 346 mV for DA-AA, DA-UA, and UA-AA, respectively. Under optimized conditions, the sensor exhibited wide linear detection ranges of 4.0 µM to 1.0 mM (AA), 0.2–100 µM (DA), and 1.0–100 µM (UA), with detection limits of 0.82, 0.002, and 0.025 M, respectively. The sensor demonstrated excellent sensitivity, selectivity, reproducibility, and stability, making it a promising platform for real-sample analysis.

The current study explores biodegradable packaging materials that have high food quality assurance, as food deterioration is mostly caused by UV degradation and oxidation, which can result in bad flavor and nutrition shortages. Thus, new multifunctional zinc oxide nanoparticles/tannic acid (ZnO@TA) with antioxidant and antibacterial activities were incorporated into polyvinyl alcohol/chitosan (PVA/CH) composite films with different ratios (1%, 3%, and 5% based on the total dry weight of the film) via a solution blending method in a neutral aqueous solution. Additionally, ZnO nanoparticles have unique antibacterial mechanisms through the generation of excessive reactive oxygen species (ROS) that may lead to intensify pathogen resistance to conventional antibacterial agents. Thus, minimizing the negative effects caused by excessive levels of ROS may be possible by developing unique, multifunctional ZnO nanoparticles with antioxidant potential via coordination bond between tannic acid and ZnO nanoparticles (ZnO@TA). ZnO@TA nanoparticles were examined using Fourier-transform infrared(FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effect of the incorporation of ZnO@TA nanoparticles on the barrier, mechanical, thermal, antioxidant, antimicrobial, and UV blocking characteristics of chitosan/polyvinyl alcohol (ZnO@TA@CH/PVA) films was investigated. The lowest water vapor and oxygen permeability and the maximum antioxidant capacity% are 31.98 ± 1.68 g mm/m² kPa day, 0.144 ± 5.03 × 10^–2 c.c/m².day, and 69.35 ± 1.6%, respectively, which are related to ZnO@TA(50)@CH/PVA. Furthermore, ZnO@TA(50)@CH/PVA film exhibits the maximum UV shielding capacity of UVB (99.994). ZnO@TA(50) @PVA/CH films displayed better tensile strength and Young`s modulus of 48.72 ± 0.23 MPa and 2163.46 ± 61.4 MPa, respectively, than the other film formulations. However, elongation % at break exhibited the most reduced value of 19.62 ± 2.3%. ZnO@TA@CH/PVA film exhibits the largest inhibition zones of 11 ± 1.0, 12.3 ± 0.57, and 13.6 ± 0.57 mm againstStaphylococcus aureus,Aspergillus flavus, andCandida albicans, respectively. In accordance with these results, ZnO@TA@CH/PVA films could be utilized for food preservation for the long-term.

Our scope is synthesis a new poly fluorobenzamide oxime ester and study its structural, optical, and dielectric properties. Consequently, ((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl) acetamide) (AIFPA) was as-synthesized via a condensation reaction of (E)-N-(4-fluorophenyl)-2-(hydroxyimino) acetamide with acrylic acid to polymerize it via free radical polymerization (PAIFPA). over and above, the synthesized PAIFPA was inserted in more polymerization action with polystyrene sulfonate through the grafting process (PAIFPA-co-PSS). The chemical structures and morphology of AIFPA, PAIFPA, and PAIFPA-co-PSS were characterized by 1H NMR, FTIR, and XRD. The crystallinity index of PAIFPA, and PAIFPA-co-PSS was studied, affording that PAIFPA-co-PSS has the highest crystallinity. Moreover, The optical bandgap that obtained from absorbance analysis was encountered to be in the range of 2.6 eV to 3.5 eV. Ultimately, the dielectric properties of PAIFPA, and PAIFPA-co-PSS showed that electric conductivity values ranged from 6.12 × 10^–8 to 7.11 × 10^–7 S.cm⁻¹, and 5.48 × 10^–10 to 7.75 × 10^–8 S.cm⁻¹, respectively. It has a great deal of interest of PAIFPA-co-PSS which has wide band gap energy as short-wavelength light absorbers to be used in tandem polymer solar cells.

The current rationale is exploring new eco-friendly UV- shielding films based on cellulose and thiazolidine. Cellulose was oxidized to dialdehyde cellulose (DAC) and tricarboxy cellulose (TCC) by periodate and TEMPO/periodate/hypochlorite, respectively. While E-3-amino-5-(phenyldiazenyl)-2-thioxothiazolidin-4-one (TH) was synthesized by coupling diazonium salt with the 5-methylene of 2-thioxo-4-thiazolidinone. DAC was then coupled with TH via Schiff base reaction and incorporated onto TCC with different ratios to get UV-shielding films. ¹HNMR, infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA) were used to investigate the chemical structure of the synthesized materials. In addition, the films' morphology, thermal, mechanical, and UV-shielding properties were investigated. The UV-shielding studies revealed that the film with 10% DAC-TH has 99.88, 99.99, and 96.19% UV-blocking (UVB), UV-absorbance (UVA), and Ultra-violet protection (UPF), respectively. Moreover, the prepared films demonstrated promising antimicrobial activity against Escherichia coli, S. aureus, P. aeruginosa, and Candida albicans. Finally, the prepared films showed no cytotoxic effects on normal human skin fibroblast's HFB-4 cell line.

The current study aims to explore the anti-corrosion performance of Poly [2 -amino -4(1 -benzyl -1H -indol - 3 -yl) thiophene - 3 - carbonitrile)] (PABITC) on C-steel in in 0.50 M H2SO4 using weight loss and potentiodynamic polarization measurements (PDP).. PABITC was synthesized with different molecular weights 882, 921, 1388, 15788 g/mol using APS as an oxidizing agent. The chemical structure of the polymer was characterized using H1NMR, DNMR, C13NMR, and FTIR spectroscopy. Polarization results reveal that the synthesized polymer acts as a hybrid-type inhibitor. The adsorption of inhibitory atoms of the polymer on the C- steel surface followed Langmuir isotherm. SEM and EDX assure the development of PABITC adsorbed film on the C- steel surface. Quantum calculations were carried out to elucidate the reactive sites in PABITC. All the results approve that PABITC makes a resistive layer to shrink the corrosion process.

Emulsion polymerization of 2-amino-4-(1-benzyl-1H-indol-3-yl) thiophene-3-carbonitrile (ABITC) using ammonium persulfate (APS) as an oxidizing agent afforded two isomers of poly (2-amino-4-(1-benzyl-1H-indol-3-yl) thiophene-3-carbonitrile) (PABITC) with high molecular weight 35673 and 28596 g/mol. Chemical structure and morphology of the newly synthesized polymers were investigated by IR, 1HNMR, SEM, and GPC. Nano capsulation of ABITC, PABITC, and PABITC/Doxorubicin by polyethylene glycol (PEG) was achieved by the nano-precipitation method. The anti-proliferative activity of the newly synthesized PABITC and nano-capsulation against HepG2, Huh7, and A549 cancer cell lines were investigated using MTT assay. The result obtained indicates that the encapsulation of ABITC inside PEG-NP led to an improvement in their anti-proliferative activity against cancer cell lines compared to free ABITC. The free PABITC revealed moderate anti-proliferative activity against tested cells and their encapsulation form with PEG-NP revealed no significant change in the activity with the fold changed not exceed 1-time fold. Furthermore, the anti-proliferative activity of PABITC -NP was improved after Doxorubicin (DOX) encapsulation against tested cells compared to PABITC - PEG-NP. In addition, PABITC exhibited potent antibacterial activity against tested microbes comparing to monomer ABITC and the reference drug amikacin. Moreover, the binding mode of the monomer ABITC beside two repeated units of monomer inside the active site of the DNA gyrase B chain (PDB ID: 1KIJ) as promising bacterial target and CDK2 enzyme (PDB ID: 1PYE)] as promising cancer target was studied using molecular docking technique.

A green approach for ethylene carbonate ring opening polymerization was proposed via an interaction between ethylene carbonate and 5-azido-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (azidopyrazole) in presence of FeCl₃ anhydrous as initiator. Despite the high thermodynamic stability of ethylene carbonate, reducing consumption of heat and time has been obtained. The effect of the molar ratio of azidopyrazole to ethylene carbonate has been studied and the resulted products were characterized.

New efficient chelating polymers (CPs) based on waste polystyrene functionalized by itaconic acid moieties in absence and presence of montmorillonite clay have been prepared using high shearing effect homogenizer. The obtained CPs have been characterized using spectrophotometric and thermal analyses. The prepared CPs have been used as potential adsorbents for removal of different toxic metal ions from their aqueous solutions. The adsorption performance of the obtained CPs was found to match well with Langmuir adsorption isotherms. The highest sorption affinity of the obtained CPs toward different metal ions was for copper and lead.