High-performance Pt/Ti3C2Tx MXene based graphene electrochemical transistor for selective detection of dopamine

Accurate measurement of dopamine (DA) is of great significance for human health monitoring and disease prevention. Herein, two-dimensional Ti 3 C 2 T x MXene with high performance was prepared by layer liquid exfoliation method and used for the modification of gate electrode. The glassy carbon electrode (GCE) modified with Pt/Ti 3 C 2 T x was used as the gate, and assembled with monolayer graphene channel to form a complete transistor device. The device combines the amplification effect of transistors, good electrical conductivity of Ti 3 C 2 T x MXene and excellent catalytic properties of Pt nanoparticles , showing a low detection limit (50 nM) and a wide detection concentration range (50 nM-9 mM) of DA. Ti 3 C 2 T x MXene not only provides a large number of attachment sites for the deposition of Pt nanoparticles , but also improves the electrical conductivity and hydrophilicity of the electrode material , thus enhancing the sensitivity of the device and facilitating the penetration of the solution to be measured. In addition, Ti 3 C 2 T x MXene is negatively charged, it has a certain electrostatic adsorption effect on protonated DA and electrostatic repulsion effect on negatively charged interfering substances. As a result, the device exhibits good selectivity , which provides a great application prospect for the construction of DA sensing platform.