Highly sensitive biosensor based on the synergistic effect of Fe3O4–Co3O4 bimetallic oxides and graphene

Abstract

A sensitive sensor for the detection of dopamine (DA) and uric acid (UA) was fabricated by Fe₃O₄–Co₃O₄ bimetallic oxides anchored at a reduced graphene oxide (rGO) film-modified glassy carbon electrode (GCE). The Fe₃O₄–Co₃O₄ and rGO showed a synergistic effect towards the electrochemical catalytic oxidation of DA and UA, with the peak currents increased by 271.7% and 590%, respectively, when compared with those on bare GCE. The as-prepared Fe₃O₄–Co₃O₄/rGO based sensor supplied with a wide linear range from 5 × 10⁻⁷ to 1.55 × 10⁻³ M and a low detection limit (LOD) of 1.3 × 10⁻⁷ M (S/N = 3) for DA detection, and the linear range for UA detection was from 1.5 × 10⁻⁶ to 1.6 × 10⁻³ M and LOD was 1.8 × 10⁻⁷ M. In addition to the anti-interference capacity of electroactive molecules like ascorbic acid and 5-hydroxytryptamine, the sensor shows high recoveries for DA and UA detection in human serum samples, indicating that the as-prepared sensor exhibited high detection sensitivity and specificity, considerable stability and reproducibility, and excellent anti-interference capability.