α-Fe2O3/rGO composites for non-enzymatic electrochemical sensing of UA and Trp and mechanism study through DFT calculation

The abnormal contain of uric acid (UA) and tryptophan (Trp) in body could cause the liver and kidney function decline. The simultaneous detection of UA and Trp for early prevention of these liver and kidney diseases is significant. This study had developed the α-Fe 2 O 3 /reduced graphene oxide (rGO) for modification of the glassy carbon electrode (GCE) in (UA) and (Trp) detection. α-Fe 2 O 3 /rGO composite was synthesized through hydrothermal-calcination method. The optimal electrochemical conditions, including the pH values, scan rate, and accumulative parameters, were discussed for demonstrating the feasibility. Moreover, this α-Fe 2 O 3 /rGO/GCE presented wide linear relationships (0.01–900 μM) and low detection limits (UA (3.56 nM) and Trp (16.4 nM)). The DFT theoretical calculation revealed that the enhanced performance is mainly due to the high electrocatalytic property of α-Fe 2 O 3 nanotube, high conductivity of rGO, and interaction effect between target biomolecule and modified electrode surface. Finally, the approving results were also acquired in detection of practical UA and Trp samples by α-Fe 2 O 3 /rGO modified GCE. The results indicate that α-Fe 2 O 3 /rGO could provide a new and highly advantageous approach for detection of UA and Trp.