Green Synthesis of Graphene Based Biomaterial Using Fenugreek Seeds for Lipid Detection

A novel, green, and sustainable route has been introduced for biosynthesis of a palladium nanoparticles (PdNPs) anchored reduced graphene oxide (rGO) platform for protein conjugation and detection of triglycerides. Fenugreek seeds (FS) were utilized for the simultaneous green reduction of Pd salt and graphene oxide (GO), which also act as a stabilizing and decorating agent for in situ grown PdNPs on rGO sheets. The well dispersed, homogeneous, and biologically reduced PdNPs having an average size of 3.5 nm on the rGO sheets are electrophoretically deposited on an indium tin oxide (ITO) glass substrate. The biosynthesized Pd-rGO sheets were characterized using spectroscopic and electrochemical techniques and further utilized for co-immobilization of lipase and glycerol dehydrogenase (LIP-GLDH) enzymes using EDC-NHS coupling chemistry. The LIP-GLDH conjugated Pd-rGO platform was used for electrochemical detection of triglycerides. The green and nontoxic approach offers enhanced stability of the fabricated biosensor as phytochemical (present in FS extract) residues available on the surface of Pd-rGO nanocomposite might have prevented the loss in the structure of the immobilized biomolecules/enzymes by providing a biocompatible coating. The fabricated Pd-rGO-based biosensor shows a wide detection range of 25-400 mg dL(-1) with an excellent sensitivity of 1.3 mu A mg(-1) dLcm(-1).