(Fe3O4)-graphene oxide as a novel magnetic nanomaterial for non-enzymatic determination of phenylalanine.

Fe3O4-graphene oxide (GO) modified glassy carbon (GC) electrode was used as a new magnetic nanosensor for determination of phenylalanine (Phe). It was found that Fe3O4-GO has been stably absorbed on GC electrode modified by simple technique. The cyclic voltammograms of the modified electrode in an aqueous solution displayed a pair of well-defined, stable and irreversible reductive/oxidation redox systems. The apparent electron transfer rate constant (k(s)) and transfer coefficient (α) were determined by cyclic voltammetry and were approximately 9.3 s(-1) and 0.67, respectively. The modified electrode showed excellent catalytic activity towards the oxidation of Phe at an unusually positive potential in buffer solution. This nanosensor also displayed fast response time, high sensitivity, low detection limit and had a remarkably positive potential oxidation of Phe that decreased the effect of interferences in analysis.