Electrochemical sensor based on CoS2 nanomaterials for selective detection of dopamine

Dopamine (DA) as an important catecholamine neurotransmitter in the human body, plays a crucial role in regulating cognition, emotions, and physical movement. Therefore, quantitative detection of DA is of great significance. Recently, transition metal sulfides such as cobalt sulfide (CoS 2 ) receive widespread attention in the field of DA detection due to their low cost, excellent catalytic performance and structural stability. To achieve the optimal electrochemical response of CoS 2 /Nafion/GCE to DA, we systematically investigate the effects of electrode coating volume, electrolyte solution pH value, and scanning speed on DA detection performance. After optimizing the above parameters, the CoS 2 /Nafion/GCE sensor exhibited excellent peak current responses for the electrochemical detection of DA. It exhibits a linear response range spanning 1.0-300.7 µM, which can be divided into two distinct segments: 1.0-108.8 µM (LOD = 0.13 µM, S/ N  = 3) and 108.8-300.7 µM (LOD = 1.3 µM, S/ N  = 3). Furthermore, the sensor demonstrates specific electrocatalytic activity toward DA, endowing it with excellent detection selectivity even in the presence of high concentrations of interfering species such as ascorbic acid, uric acid, and glucose. In the detection of real samples of human urine, the recovery rate of DA is 95.47% to 101.78%. This result provides an ideal material platform for developing highly selective and low-cost DA detection sensors.