Dithiocarbamate to modify magnetic graphene oxide nanocomposite (Fe 3 O 4 -GO): A new strategy for covalent enzyme (lipase) immobilization to fabrication a new nanobiocatalyst for enzymatic hydrolysis of PNPD.

Immobilization of lipase was successfully achieved on the surface of magnetically separable Fe3 O4 /graphene oxide (GO) via a post-modification. This post modification was achieved in alternation to glutaraldehyde post-modification. The activity of immobilized lipase had not a significant loss in the activity while on the other hand, it is simply extractable (by keeping its major activity) from reaction crude by a magnet. Each step of immobilization was carefully monitored by characterization and all were successfully proved. SEM, TEM, XRD, EDX, and FTIR were used to characterize the support and immobilization process.