Electroanalytical sensor based on CuInSe₂/carbon sphere towards the non-invasive determination of dopamine

Dopamine (DA) is known as a crucial neurotransmitter synthesized and secreted by dopaminergic neurons and plays a role in regulating human emotions and behaviors. The determination of DA content is of great significance in clinical application and physiological function research. An electroanalytical sensor based on the ternary semiconductor material copper indium selenide (CuInSe2) coated carbon spheres functionalized glassy carbon electrode (CuInSe2@CS/GCE) towards the non-invasive determination of DA was constructed in this study. The performances of the sensor were characterized using cyclic voltammetry, impedance method, and differential pulse voltammetry. The results show that wrinkled CuInSe2 completely coated on CS. The sensor exhibits good electrochemical kinetics and response signal towards DA, which results from the good electrochemical activity and excellent electroconductibility of transition metal centers of the composite. The determination limit of the proposed sensor towards DA is 0.59 mu M (S/N=3), and the linear measuring range is between 1-800 mu M. In addition, the sensor exhibits desirable long-term robustness, reproducibility, repetitiveness, and interference immunity. In the non-invasive determination towards real samples of human urine and sweat, the sensor provides good recovery rate and small determination deviation.