Physico-chemical characteristics of free and immobilized lipase; a FT-IR spectroscopy of free and immobilized lipase, b CLSM images of FITC-labelled immobilized lipase, c magnetization studies of CuFe2O4 hollow magnetic nanoparticles with and without the immobilized enzyme, relative activity of lipase free (■, black filled square) and immobilized lipase (●, red filled circle) as a function of d pH and e temperature (color figure online)