Detection of other neurochemicals at CNT-Nb
microelectrodes. (Upper
row) CVs of (A) 200 μM AA, (C) 20 μM DOPAC, (E) 1 μM
serotonin, (G) 1 μM adenosine, and (I) 1 μM histamine
in PBS buffer. Red dashed line is CV of 1 μM dopamine obtained
from the same CNT-Nb electrode. For AA, DOPAC, and serotonin, the
electrode was scanned to 1.3 V; for adenosine and histamine, the electrode
was scanned to 1.45 V. (Lower row) Column plots show the ratio of
oxidation current for (B) 200 μM AA, (D) 20 μM DOPAC,
(F) 1 μM serotonin, (H) 1 μM adenosine, and (J) 1 μM
histamine compared to the corresponding oxidation current of dopamine
at CNT-Nb microelectrode (black, n = 5) and CFMEs
(gray, n = 5). The oxidation current ratios at CNT-Nb
microelectrodes are significantly different than CFMEs for the measurement
of ascorbic acid (paired t test, p < 0.0001) and histamine (paired t test, p < 0.05).