Nanomaterial-based electrochemical sensors for the detection of neurochemicals in biological matrices

Neurochemicals such as dopamine, glutamate, GABA, adenosine, and serotonin are efficient indicators for quantifying the dynamics of many brain disorders. Both in vivo and in vitro detection strategies for those neurochemicals are important in treating various human diseases. Along with common, conventional tools (e.g., microelectrodes, biosensors, spectrophotometry, Fourier transform infrared, Raman, chromatography, fluorescence, flow injection, and capillary electrophoresis), electrochemical sensors based on nanomaterials (NMs; e.g., graphene, carbon nanotubes, molecular imprinted polymers, metal organic frameworks, and metallic nanoparticles) have emerged as potent tools for the quantitation of neurochemicals due to their robust designs, selectivity, sensitivity, precision, and accuracy. The performance of the latter varies widely because of differences in their sensing efficiencies. This review provides a brief introduction to those electrochemical sensors with a detailed overview of the latest trends, limitations of NM-based sensing techniques, and the potential for their future expansion for various neurochemicals.