Table 1. Summary of Responses to Serotonin by Boron-Doped Diamond vs Bare or Nafion-Coated Carbon Fiber Microelectrodes^a.

	signal (nC/mm2)	S/N	S/B (%)	LOD (nM)
BDMs	8.4 ± 0.4	210 ± 30	17 ± 1	13 ± 3
Nafion-coated CFMs	6.8 ± 0.8	48 ± 7***	2.9 ± 0.4***	64 ± 8***
CMFs	5.3 ± 0.7*	48 ± 8***	2.7 ± 0.4***	67 ± 7***

^aBoron-doped diamond microelectrodes (BDMs) showed significantly higher signal-to-noise and signal-to-background ratios and better limits of detection compared to those of Nafion-coated or bare carbon fiber microelectrodes. The absence of redox-active ionizable surface groups and lower concentrations of internal charge carriers in BDMs lead to lower background currents and noise. Data are mean responses to 1 μM serotonin ± SEMs (n = 8 − 18 samples per data point). The oxidative potential was 0.8 V for BDMs and 0.55 V for CFMs and Nafion-coated CFMs, while the reductive and resting potentials were 0 V for all electrodes. *P < 0.05 and ***P < 0.001 vs BDMs.