Modification of Gold Substrate With Fe 3 O 4 -Graphene Nanocomposite to Increase Resolution of Surface Plasmon Resonance (SPR) Glucose Sensor.

In this study, magnetite (Fe3O4) was composited with graphene (Gr) and used as a non-enzymatic glucose sensor material based of surface plasmon resonance (SPR). The Fe3O4 nanoparticles were succesfully synthesized by ultrasonic co-precipitation method while variation composition of composite samples was successfully prepared at room temperature by varying the concentration ratio of graphene and Fe3O4. The resulting composites have good crystallinity and purity with Fe3O4 nanoparticles attach on the graphene surface. The commercial gold (Au) chip with a thickness of 50 nm was modified with a composite by depositing the various compositions of the composite on the Au chip surface using a spin coater. The most optimal SPR response was shown by the Fe3O4-Gr (3:1) sample with a shift in resonance intensity of 18.2 r.u in detecting 5 mM of glucose. Moreover, the detection limit of the synthesized sensor reaches 0.1995 mM and has good stability at 20 measurement cycles. [ABSTRACT FROM AUTHOR]