Fig. 2: Performance of scalable CCM array.
From: Stabilized carbon coating on microelectrodes for scalable and interoperable neurotransmitter sensing
a 100-channel CCM arrays on silicon (left) and 25.4-μm-thick Kapton (flexible, right) substrate. Inset: Corresponding magnified view of two CCMs. b Mean and individual cyclic voltammograms (100 mV/s) of CCMs in a 100-channel CCM array in PBS (pH 7.4). 99 out of the 100 channels are included. Inset: Cyclic voltammogram of a representative Au microelectrode. c Concentration-dependent response of a CCM to DA. Left: background-subtracted color plot (bottom) and current-time trace at 0.6 V (top). Right: Background-subtracted cyclic voltammograms for the indicated DA concentrations. d Oxidation peak current at 0.6 V vs. DA concentration over 50–1000 nM at CCMs (n = 4 CCMs, mean ± SD) and commercial CFEs. The sensitivity is 125.5 vs. 15.5 nA/μM. e Cyclic voltammogram in the presence of 5 nM DA to show the low LOD of a CCM. f Schematic of the 100-channel CCM array testing in PBS (left) and the heatmap of background current value at 0.6 V with respect to actual channel position (right). g Histogram of the peak current to background current ratio (PC/BC, sensitivity) of the 100-channel CCM array. Inset: Voltammograms illustrate the background current at 0.6 V (BC) and the peak current of the background-subtracted cyclic voltammograms in the presence of 1 μM DA (PC). h Histogram of the peak-to-peak potential distance (Vp-p) of 100-channel CCM array. The voltammogram in the inset illustrates the Vp-p: potential difference between the oxidation peak and reduction peak of 1 μM DA. FSCVs were conducted with a scan range of −0.4 to 1.1 V, a scan rate of 400 V/s, and at 10 Hz. Ninety-eight out of the 100 channels function for DA sensing, exhibiting consistent DA sensing results.
