One-step preparation of carbon quantum dots-reduced graphene oxide nanocomposite-modified glass carbon electrode for the simultaneous detection of ascorbic acid, dopamine, and uric acid

In this manuscript, carbon quantum dots-reduced graphene oxide (CQDs-rGO) nanocomposite was modified on the surface of glass carbon electrode (GCE) via an one-step co-deposition method to fabricate an effective electrochemical senor for the simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Due to the strong synergetic effect between CQDs and rGO, the sensor exhibited good selectivity and high catalytic activity toward AA, DA, and UA. The peak potential differences of simultaneous detection for AA-DA, DA-UA, and AA-UA were calculated as 0.147 V, 0.135 V, and 0.282 V, respectively. And the linear responses of AA, DA, and UA were found in the ranges of 0.2-0.9 mM(R-2 = 0.99) and 1.4-4.2 mM (R-2 = 0.99), 5-9 mu M (R-2 = 0.98) and 11-81 mu M (R-2 = 0.99), and 20-90 mu M (R-2 = 0.99) and 140-300 mu M (R-2 = 0.99), respectively. The as-prepared sensor contributed a fresh idea to the simultaneous detection of AA, DA, and UA, and has a broad prospect in practical application.