Shrink-Induced Highly Sensitive Dopamine Sensor Based On Self-Assembly Graphene on Microelectrode

This paper presents a highly sensitive dopamine microelectrode fabricated by self-assembly of graphene on a gold electrode with polystyrene shrink polymer substrate. Nano graphene wrinkles and gaps are formed on the rough gold layer after shrinkage, significantly enhancing the sensor performance for dopamine detection. Compared with the bare gold electrode, the normalized sensitivity of graphene-shrink electrode improved over 130 times from 0.22 nA·μM^-1·mm^-2 to 28.77 nA·μM^-1·mm^-2. The detection limit of dopamine achieved 5 nM, meeting the in-vivo detection requirements. The sensitivity of the shrink electrode increased 23 times from 0.22 nA·μM^-1·mm^-2 to 5.05 nA·μM^-1·mm^-2. This simple dopamine sensor with high sensitivity and low detection limit can be widely used in real-time dopamine recording.