Inkjet-Printed Sensors Based on Nanoferrite-Doped Manganese Oxide Nanoparticles for the Sensitive Differential Pulse Voltammetric Determination of Brimonidine.

The present study described the construction and the electrochemical futures of a novel inject-printed electrochemical sensor based on spinel ferrite-doped manganese oxide nanoparticles (FMnONPs) for the sensitive differential pulse voltammetric quantification of brimonidine (BRIM) in ophthalmic solutions. At the optimized electroanalytical parameters, calibration graphs were linear within the BRIM concentration range of 24-3512 ng mL-1 and recorded a detection limit value of 8.21 ng mL-1. Cyclic voltammograms recorded at different scan rates indicated an adsorption-reaction mechanism for the electrooxidation of BRIM at the electrode surface with the involvement of two electrons and one proton based on the oxidation of the five-membered ring nitrogen atom as recommended by the molecular orbital calculations. The enhanced performance of the introduced inkjet-printed sensors integrated with FMnONPs encourages their application for monitoring BRIM residues in ophthalmic solutions and biological fluids in the presence of BRIM degradation products and other interferents for diverse quality control applications.

Manufacturing of Corrosion Inhibitors and Flow Improvers from Recycling of Waste at Hail City, Saudi Arabia: Physicochemical and Electrochemical Studies on Steel in Petroleum Industries.

The aim of the present research paper is to convert daily waste materials generated by human activity at Hail city into useful petroleum additives. In this respect, novel multifunctional corrosion inhibitors working as inhibitors and flow improvers for crude oil were prepared. Polyethylene terephthalate (PET) plastic waste is used in the production of corrosion inhibitors and flow improvers for petroleum crude oil. A multifunctional corrosion inhibitor for the SABIC carbon steel in corrosive seawater for application in the petroleum industry was manufactured using PET waste that was gathered, cleaned, and used as starting materials. The PET green recycling method takes place via the Abdel-Hameed green recycling reported method. In the first step, PET waste was reacted without a solvent with a diamine to form the diamino derivative of phthalic acid amide (PETAA), which was characterized by FT-IR, 1HNMR, and elemental analysis. In the presence of a catalyst, the used recycling method is a solvent-free green recycling process that is environmentally friendly. Chemical and electrochemical measurements were performed, and the effects of concentration and temperature were studied. The inhibition efficiency was found to increase with concentration. A maximum inhibition of 97% was obtained using 4000 ppm from the prepared PETAA inhibitor, while the efficiency decreased with temperature. Potentiodynamic polarization (PDP) data indicates the mixed-type nature of the used inhibitor. According to potentiodynamic polarization data, the inhibitor boosts polarization resistance and inhibition performance by adsorbing on the metal/electrolyte interface. The data from electrochemical impedance spectroscopy (EIS) show that the charge-transfer mechanism is the primary governing factor in the steel dissolution process. The size of the semicircle grows in direct proportion to the concentration of the inhibitor. The prepared additive acts as a flow improver (viscosity improvers and pour point depressants) for waxy crude oil, indicating that it can be used in the manufacturing of multifunctional inhibitors in the petroleum industry. The depression in the pour point temperatures depended on the concentration and composition of the additive prepared from the plastic waste collected from Hail city.

Novel Copper Oxide-Integrated Carbon Paste Tirofiban Voltammetric Sensor.

The present study introduced the construction and electroanalytical characterization of novel tirofiban (TIR) carbon paste voltammetric sensors integrated with copper oxide nanoparticles. The copper oxide nanostructure remarkably enhanced the oxidation of TIR molecules on the electrode surface with an irreversible anodic oxidation peak at about 1.18 V. The peak current values of the recorded differential pulse voltammograms were correlated to the TIR concentrations within a defined linear range from 0.060 to 7.41 µg mL-1 with an LOD value of 20.7 ng mL-1. Based on the electrochemical behavior of TIR at different scan rates and with the aid of the molecular orbital calculations performed on the TIR molecule, the electro-oxidation reaction was postulated to undergo through the oxidation of the five-membered-ring nitrogen atom with the transfer of one electron and one proton. Based on the reported selectivity and sensitivity of the proposed method, TIR was successfully determined in Aggrastat intravenous infusion and biological samples with mean average recoveries agreeable with the UV spectrophotometric method.

Equilibrium and Kinetic Study of Anionic and Cationic Pollutants Remediation by Limestone-Chitosan-Alginate Nanocomposite from Aqueous Solution.

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone-chitosan-alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol-1 for CR and 8.71 KJ mol-1 for BG, while the entropy change (ΔS0) was 89.1 J K-1 mol-1 for CR and 79.1 J K-1 mol-1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.

Study of reactivity of cyanoacetohydrazonoethyl-N-ethyl-N-methyl benzenesulfonamide: preparation of novel anticancer and antimicrobial active heterocyclic benzenesulfonamide derivatives and their molecular docking against dihydrofolate reductase.

This article describes the synthesis of some novel heterocyclic sulfonamides having biologically active thiophene 3, 4, 5, 6, coumarin 8, benzocoumarin 9, thiazole 7, piperidine 10, pyrrolidine 11, pyrazole 14 and pyridine 12, 13. Starting with 4-(1-(2-(2-cyanoacetyl)hydrazono)ethyl)-N-ethyl-N-methylbenzenesulfonamide (2), which was prepared from condensation of acetophenone derivative 1 with 2-cyanoacetohydrazide. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H NMR, 13C NMR, 19F NMR and MS spectral data. All the newly synthesized heterocyclic sulfonamides were evaluated as in-vitro anti-breast cancer cell line (MCF7) and as in-vitro antimicrobial agents. Compounds 8, 5 and 11 were more active than MTX reference drug and compounds 12, 7, 4, 14, 5 and 8 were highly potent against Klebsiella pneumonia. Molecular operating environment performed virtual screening using molecular docking studies of the synthesized compounds. The results indicated that some prepared compounds are suitable inhibitor against dihydrofolate reductase (DHFR) enzyme (PDBSD:4DFR) with further modification.