An Electrochemical Sensor Based on Carbon Quantum Dots and Ionic Liquids for Selective Detection of Dopamine

Abstract Dopamine (DA) as a neurotransmitter has a pivotal role in the central nervous system. Because of altered levels of DA in various neuroscience diseases, development of a quick, sensitive, and simple analytical approach to determine DA in biological fluids could be very applicable. In this research, a novel electrochemical sensor based on a carbon paste electrode (CPE) modified with ionic liquid (IL) and carbon quantum dots (CQDs) for measuring DA with uric acid and ascorbic acid was developed. IL and CQDs were synthesized and characterized for their specific properties such as composition, emission, size distribution, and morphology structure. Then, the modified CPE and different DA concentration was determined via cyclic voltammetry. The modified electrode exhibited great electrocatalytic activity for DA oxidation. Under optimal conditions, the calibration diagram for DA was linear within the range of 0.1–50 μM in phosphate buffer (pH=7.4) and limit of detection was 0.046 μM. The electrode was successfully used in the determination of DA in real samples and generated acceptable outputs. The proposed electrochemical sensor could be an exceptional step forward in DA detection and pave the way for the molecular diagnosis of neurological illnesses.