Synthesis of amino-silane modified superparamagnetic Fe3O4 nanoparticles and its application in immobilization of lipase from Pseudomonas fluorescens Lp1

Superparamagnetic nanoparticles (Fe3O4–magnetite) were prepared by chemical co-precipitation method and their surface was functionalized with 3-aminopropyltriethoxysilane via silanization reaction to obtain amino functionalized magnetic nanoparticles. The purified lipase from Pseudomonas fluorescens Lp1 was immobilized onto functionalized magnetite using glutaraldehyde as the coupling agent. The characterization of the nanoparticles was done by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, vibrating sample magnetometry and Fourier transformed infrared spectroscopy. The size of the magnetite was measured about 10–30 nm. The results of characterization study revealed the successful immobilization of lipase on to functionalized magnetite. The saturation magnetization of magnetic nanoparticles was found to be 28.34 emu/g whereas the immobilized magnetic nanoparticle was 17.074 emu/g. The immobilized lipase had greater activity at 50 °C and thermal stability upto 70 °C. It exhibited excellent reusability for 4 cycles and storage stability upto 15 days by retaining 75% of its initial activity.

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► Magnetic nanoparticles were synthesized by chemical co-precipitation method.
► Surface was functionalized with amino-silane and used for lipase immobilization.
► Characterized through TEM, SEM, XRD, FT-IR and VSM analysis.
► The functionalization and immobilization did not affect the magnetite properties.
► The immobilized lipase showed greater functional property than free lipase.