A Recognition-Molecule-Free Photoelectrochemical Sensor Based on Ti(3)C(2)/TiO(2) Heterostructure for Monitoring of Dopamine

Herein, a novel, recognition-molecule-free electrode based on Ti(3)C(2)/TiO(2) composites was synthesized using Ti(3)C(2) as the Ti source and TiO(2) in situ formed by oxidation on the Ti(3)C(2) surface for the selective detection of dopamine (DA). The TiO(2) in situ formed by oxidation on the Ti(3)C(2) surface not only increased the catalytically active surface for DA binding but also accelerated the carrier transfer due to the coupling between TiO(2) and Ti(3)C(2), resulting in a better photoelectric response than pure TiO(2). Through a series of experimental conditions optimization, the photocurrent signals obtained by the MT100 electrode were proportional to the DA concentration from 0.125 to 400 µM, with a detection limit estimated at 0.045 µM. We also monitored DA in human blood serum samples using the MT100 electrode. The results showed good recovery, demonstrating the promising use of the sensor for the analysis of DA in real samples.