Paper-Based Electrochemical Biosensors for Point-of-Care Testing of Neurotransmitters

Neurotransmitters are important biological molecules related to several nervous system diseases (NSDs). Point-of-care testing (POCT) of neurotransmitters is of great importance in preclinical research and early diagnosis of NSDs. Among various POCT platforms, paper-based electrochemical biosensors have achieved great advances in detection of neurotransmitters, thus taking a significant role in POCT of neurotransmitters nowadays. This review gives an overview of the recent advances of paper-based electrochemical biosensors for POCT of neurotransmitters. We first introduce the types of neurotransmitters and biological sample sources mainly used for neurotransmitter detection. Second, we review the components and the traditional fabrication technologies for paper-based electrochemical POCT biosensors, and then the functional modification methods of biosensor surfaces and three-dimensional fabrication methods for further enhancement of their detection performance. Then, we list examples of paper-based electrochemical biosensors used for detecting different neurotransmitters in biological samples. Last, we give a conclusion and promising development direction of paper-based electrochemical biosensors for neurotransmitters detection. The purpose of this review is to introduce the paper-based electrochemical biosensors as an emerging technology for POCT of neurotransmitters, offering a reference for readers and researchers for early diagnosis of NSDs using POCT technologies.