Graphene oxide fiber microelectrodes with controlled sheet alignment for sensitive neurotransmitter detection.

Here, we synthesized and characterized graphene oxide (GO) fiber microelectrodes with controllable nanosheet orientation to study the extent to which sheet alignment and orientation impacts electrochemical detection of neurochemicals. The alignment of the GO nanosheets was characterized by scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry. The electrochemical performance of GO microelectrodes and its suitability for subsecond detection of neurotransmitters was further evaluated by fast-scan cyclic voltammetry (FSCV). We have shown that the GO sheet alignment has a considerable effect on the electron transfer kinetics, frequency independent behavior, and detection suitability for specific neurotransmitters. Therefore, this fine-tuning aspect of the electrode surface for specific electrochemical detection should be taken into consideration for any future utilization of GO-based biological sensors.