971942.fig.003a
(a)
971942.fig.003b
(b)
971942.fig.003c
(c)
971942.fig.003d
(d)
Figure 3: SEM images of the carbon plate as model electrode (a), MWNT-modified electrode (b), COOH/MWNT-modified electrode (c), and AChE-ChOx/COOH/MWNT-modified electrode (d).