Hydrophilic antifouling 3D porous MXene/holey graphene nanocomposites for electrochemical determination of dopamine

Dopamine (DA) detection is essential for diagnosis and evaluation of diseases such as Parkinson's, Alzheimer and schizophrenia. However, conventional electrochemical sensors are vulnerable to biofouling in complex biological fluids, which leads to significant decrease in sensor performance. Ti3C2Tx MXene, a novel 2D material with excellent conductivity and hydrophilicity, is a potential antifouling material for electrodes. But oxidation can strongly influence the performance of MXene. In this work, an antifouling electrochemical sensor for DA detection was fabricated by combining MXene and holey graphene (HG). Multilayer MXene (M-MXene) and single-layer MXene (S-MXene) were combined with HG to form a 3D porous network. HG not only prevented the restacking of MXene but it also improved the stability of MXene. Owing to the excellent conductivity and large surface area, S-MXene/HG modified electrode had a fast electron transfer and excellent electrocatalytic activity for DA compared with M MXene/HG. Furthermore, S-MXene/HG possessed higher surface hydrophilicity and enhanced biofouling resistance than M MXene/HG and HG modified electrode. S-MXene sensor displayed excellent analytical performance for DA and antifouling ability in complex fluids. It offers new promising possibilities for its clinical application.