Application of MXene in the Electrochemical Detection of Neurotransmitters: A Review

Neurotransmitters are small chemical signaling molecules crucial for the proper function of the nervous system. The dysregulation of neurotransmitters results in several mental disorders like Parkinson's and Alzheimer's diseases, schizophrenia, and conditions such as depression and addiction. These signaling molecules are present at low concentrations, and obtaining information about these molecules' levels is vital. Moreover, neurotransmitter monitoring in the nervous system remains challenging due to its low concentrations and rapid response. Electrochemical detection continues to garner significant attention as an attractive technique due to its facile nature, high sensitivity, and cost-effectiveness. The electroactive materials of electrochemical sensors are at the heart of this sensing technology. Although multiple nanomaterials have been explored as active components in electrochemical sensors for detecting neurotransmitters, MXenes are gaining attention in the electrochemical sensing of neurotransmitters. This review aims to discuss the use of MXenes and their composites for the electrochemical detection of neurotransmitters, describe the various MXene composites based on the nature of the composite viz pristine and chemical functionalized, carbon nanomaterial, polymer, metal nanoparticle, and transition metal dichalcogenide (TMDC) composites, and define the future directions in leveraging the properties of MXene composites for early-stage electrochemical detection of neurological diseases originating from an imbalance in neurotransmitters.