Radioiodinated Magnetic Nanoparticles Conjugated With Moxifloxacin: Synthesis andIn VitroBiological Affinities

Stability evaluation of 6-phosphogluconate dehydrogenase immobilized on amino-functionalized magnetic nanoparticles

In this study, 6-phosphogluconate dehydrogenase was covalently immobilized onto the N-2-aminoethyl-3-aminopropyltriethoxysilane (APTES) modified core-shell Fe₃O₄@SiO₂ magnetic nanoparticles (ASMNPs) using glutaraldehyde (GA). Immobilization of 6PGDH on ASMNPs was confirmed using fourier transform-infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) analysis. The NADP⁺ conversion ratio, the reusability, thermal, and storage stability of the immobilized 6PGDH were determined and compared with those of the free enzyme. The maximum retention of enzyme activity reached to 96% when the enzyme was immobilized on ASMNPs activated with monomer form of GA. Although the thermal stability of free and immobilized enzymes was similar, at 30 °C, the immobilized 6PGDH showed the improved thermal stability at 40 °C and 50 °C compared with free 6PGDH. While the free 6PGDH only converted 33% of NADP⁺ in reaction medium upon 480 s, the immobilized 6PGDH performed 56% conversion of NADP⁺ at same time. The immobilized 6PGDH retained 62% of its initial activity up to the fifth cycle and 35% of its initial activity after 22 days of storage at 4 °C.

Environmental implications and applications of engineered nanoscale magnetite and its hybrid nanocomposites: A review of recent literature

This review focuses on environmental implications and applications of engineered magnetite (Fe3O4) nanoparticles (MNPs) as a single phase or a component of a hybrid nanocomposite that exhibits superparamagnetism and high surface area. MNPs are synthesized via co-precipitation, thermal decomposition and combustion, hydrothermal process, emulsion, microbial process, and green approaches. Aggregation/sedimentation and transport of MNPs depend on surface charge of MNPs and geochemical parameters such as pH, ionic strength, and organic matter. MNPs generally have low toxicity to humans and ecosystem. MNPs are used for constructing chemical/biosensors and for catalyzing a variety of chemical reactions. MNPs are used for air cleanup and carbon sequestration. MNP nanocomposites are designed as antimicrobial agents for water disinfection and flocculants for water treatment. Conjugated MNPs are widely used for adsorptive/separative removal of organics, dyes, oil, arsenic, phosphate, molybdate, fluoride, selenium, Cr(VI), heavy metal cations, radionuclides, and rare earth elements. MNPs can degrade organic/inorganic contaminants via chemical reduction or catalyze chemical oxidation in water, sediment, and soil. Future studies should further explore mechanisms of MNP interactions with other nanomaterials and contaminants, economic and green approaches of MNP synthesis, and field scale demonstration of MNP utilization.