Table 1.

Sensitivity of CFEs in amperometric and CV modes to different metabolic compounds

Compound AaBa Δl at 10 μmb Ratioc
Amperometry
    DA 0.86 ± 0.02 0.62 ± 0.04 30 1
    NE 0.89 ± 0.02 0.61 ± 0.03 32 1
    EP 0.85 ± 0.01 0.6 ± 0.02 28 1.1
    I-DOPA 0.8 ± 0.01 0.67 ± 0.02 30 1
    DOPEG 0.62 ± 0.02 0.73 ± 0.04 22 1.3
    DOPAC 0.7 ± 0.02 0.68 ± 0.04 24 1.3
    HVA 0.74 ± 0.01 0.64 ± 0.02 24 1.3
    AA 0.69 ± 0.01 0.7 ± 0.02 25 1.2
CV
    DA 2.71 ± 0.03 0.72 ± 0.04 2690 1
    NE 2.39 ± 0.08 0.81 ± 0.07 1580 1.7
    EP 2.21 ± 0.28 0.8 ± 0.27 1030 2.6
    I-DOPA 1.64 ± 0.13 0.77 ± 0.09 250 10.8
    DOPEG 1.64 ± 0.13 0.89 ± 0.1 340 7.9
    DOPAC 1.31 ± 0.25 0.84 ± 0.16 140 19.2
    HVA 1.54 ± 0.2 0.85 ± 0.15 240 11.2
    VMA 1.69 ± 0.11 0.5 ± 0.07 150 17.9
    AA 0.95 ± 0.15 0.79 ± 0.06 50 53.8

  • ↵ a Calibration coefficients were derived from the linear fit, log(Δl) = A + B* log(C), where Δl is in picoamperes and C is in micrometers. Examples of the calibration curves are shown in Figures 2D and 4D. For CV calibrations, the reference background current, lBStd, was set at 30 nA. The coefficients are shown with the experimental errors

  • ↵ b Current was calculated using the formula, ΔlC = 10^[A + B* log(C)], where ΔlC (pA) is an oxidative current at C (μm) concentration of a compound. For CV calibrations, Δlnorm values are presented (see Results)

  • ↵ c Ratio was calculated between Δl at 10 μm for DA and other compounds