Figure 3: In vivo neural recordings in rats.
The data presented here are representative of three different acute experiments, each of them lasting 5–6 h. (a) The photograph of a 50 × 50 μm2 single-graphene electrode placed on the cortical surface of the left hemisphere and a 500 × 500 μm2 single-Au electrode placed on the cortical surface of the right hemisphere. The inset shows the flexibility of the electrodes. (b) Interictal-like spiking activity recorded by 50 × 50 μm2 doped-graphene and Au electrodes. Both electrodes were placed on the same hemisphere and connected to the same amplifier channel in subsequent recordings. Data were filtered with a 0.1 Hz–3 kHz bandpass filter. Recordings with doped-graphene electrodes are five- to sixfold less noisy compared with the ones with same size Au electrode. (c) Power density spectra of the recordings shown in b calculated over 20 s time window. Doped-graphene electrode recorded significantly lower 60 Hz noise and its harmonics. The inset shows almost two orders of magnitude decrease in 60 Hz electrical interference noise. (d) Seizure-like discharges recorded by 50 × 50 μm2 doped-G and 500 × 500 μm2 Au electrodes simultaneously according to the electrode placement shown in a. Similar SNR are observed for both recordings.
