Electrochemical detection mechanism of dopamine and uric acid on titanium nitride-reduced graphene oxide composite with and without ascorbic acid

Chrysanthemum-like titanium nitride-reduced graphene oxide (TiN-rGO) composite was synthesized involving the hydrothermal and nitridation process. The rGO does not change the chrysanthemum-like structure of TiN while enhancing the electroactive surface area. Based on this, the electrochemical sensor was prepared by adopting TiN-rGO to modify glassy carbon electrode (GCE). Due to the synergic effects of TiN and rGO, the sensor exhibits good electrocatalytic activity especially toward the detection of dopamine (DA) and uric acid (UA). The linear detection ranges are 5-175 mu M and 30-215 mu M, with detection limits of 0.159 mu M and 0.350 mu M for DA and UA (S/N = 3), respectively. When ascorbic acid (AA) coexists with DA and UA, the peaks of the three substances based on the electrode can be separated. The electrochemical detection mechanism shows that AA can be detected at low concentrations, i.e. below 100 mu M, which can meet the needs of human body. In addition, the sensor exhibits good anti-interference, stability, reproducibility and satisfactory recovery results in real samples.