Microwave-assisted ultrafast synthesis of TiO2/MXene/rGO heterojunction electrodes for high-sensitivity electrochemical dopamine detection

Dopamine (DA) serves as a vital neurotransmitter involved in reward mechanisms, motor coordination, and cognitive processes, establishing the importance of its reliable detection for diagnosing associated neurological disorders. This study presents a microwave-assisted synthesis strategy for rapid fabrication of TiO 2 /MXene/rGO heterojunction nanomaterials, engineered for ultrasensitive electrochemical DA detection. The ternary composite demonstrated significantly enhanced electrocatalytic performance, attributable to the synergistic combination of abundant oxygen vacancies, exceptional electrical conductivity, and ultrahigh specific surface area. These characteristics collectively provide substantial active sites and enable efficient electron transfer during DA oxidation. As a result, the obtained TiO 2 /MXene/rGO electrode exhibits remarkable analytical performance with dual linear response ranges of 0.01–2.4 μM and 2.4–50 μM, a high sensitivity of 21.893 μA μM −1 , and an ultralow detection limit of 5.1 nM. The sensor also demonstrates excellent reproducibility, repeatability, and outstanding selectivity against interfering substances. Moreover, the sensor was applied to determine DA in real samples with satisfactory results.