Modification of bimetal Zn/ Mg MOF with nanoparticles Fe3O4 and Fe3O4@SiO2, investigation of the peroxidase-like activity of these compounds by calorimetry and fluorimetry methods.

In this article; the bimetal metal-organic framework Zn/Mg (Zn/Mg MOF) is synthesized. Then Zn/Mg MOF bimetal was combined with Fe3O4 and Fe3O4@SiO2, and composites of Fe3O4@ SiO2/MOF/Dextrin, Fe3O4@SiO2/MOF, Fe3O4@MOF/Dextrin and Fe3O4@MOF made. The peroxidase-like activity of these compounds was investigated and compared by calorimetric Resazurin (Rz) and O-phenylenediamine (OPD); (Rz-H2O2, OPD-H2O2) and fluorimetric Rz and terephtalic acid (TA); (Rz-H2O2, TA-H2O2). The Fe3O4@ MOF/Dextrin composite has the highest peroxidase-like activity. The effect factors (amount of pH (6), the values of TA (1.37 mM), H2O2 (0.025 mM), reaction time (8.15 min), and amount of Composite (116.67 mg)) to increase the catalytic activity of Fe3O4@ MOF/Dextrin measured by chemometrics method. The most suitable linear range of the calibration curve by the TA-H2O2 -Composite fluorimetric method is 1-600 µg L-1, and the detection limit is 2.27 µg L-1. The relative standard deviation (RSD%) for measuring concentration atropine 1 µg L-1 (n = 6) is 1.18%. Finally, from this system for measuring atropine extracted by the Liquid-liquid extraction (LLE) method in two types of plants, D. Innoxia north and west and D. stramonium north and west of Iran (118.25 µg L-1, 79.80 µg L-1) and (18.477 µg L-1, 9.27 µg L-1) used, respectively.

Synthesis and characterization of cadmium selenide quantum dots doped by europium and investigation of their chemiluminescence properties and antibacterial activities.

Nanoparticles of cadmium selenide (CdSe) doped with europium, were synthesized as stabilizing agents using thioglycolic acid ligand. This method is based on the enhancing effect of CdSe quantum dots (QDs) doped with europium on chemiluminescence (CL) emission. This emission was generated by mixing CdSe QDs with manganese (II), iron (II) and chrome (II) sulfates as catalysts in the presence of hydrogen peroxide (H2 O2 ). The structural characteristics and morphology of these nanoparticles were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, X-ray pattern and dynamic light scattering methods. The CdSe QDs doped with europium were used as the sensitizer in a luminol-hydrogen peroxide CL system. The sensitized CdSe QDs were analyzed for antibacterial activity against Gram-positive or Gram-negative bacteria. The results showed that the CdSe QDs are effective against all the studied bacteria, effectiveness was especially higher for Bacillus subtilis.