Graphene Probes for Detecting Electrical Activity of Individual Synapses

Complex neural circuits connected by billions of neurons with trillions of synapses require techniques that map the electrical activity of neural networks with extraordinary temporal and spatial resolution to decipher the underlying mechanisms for multiple aspects of neuroscience. By combining graphene transistors with scanning photocurrent microscopy, we can detect the local electrochemical environment changes induced by electrical activity of individual synapses of primitive hippocampal neurons, enabling us to estimate extracellular potential variations of individual synapses during depolarization. The ultrafast nature of graphene photocurrent response allows decoding of the activity patterns of individual synapses with sub-millisecond temporal resolution. As such, our new neurotechnology will offer promising potential for recording the electrical signals of a large population of synapses in neural networks.