A Recognition-Molecule-Free Photoelectrochemical Sensor Based on Ti3C2/TiO2 Heterostructure for Monitoring of Dopamine

Herein, a novel, recognition-molecule-free electrode based on Ti3C2/TiO2composites was synthesized using Ti3C2as the Ti source and TiO2in situ formed by oxidation on the Ti3C2surface for the selective detection of dopamine (DA). The TiO2in situ formed by oxidation on the Ti3C2surface not only increased the catalytically active surface for DA binding but also accelerated the carrier transfer due to the coupling between TiO2and Ti3C2, resulting in a better photoelectric response than pure TiO2. 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.Keywords:photoelectrochemical;MXene;dopamine sensor