Electrochemical Analysis of Ion Channels and Transporters in Pore-Suspending Membranes - Applications of Electrochemistry and Nanotechnology in Biology and Medicine - page 319

200

150

100

50

0

0.0 0.2 0.4 0.6 0.8 1.0

relative light intensity

Figure 19. Maximum current density J max as a function of light intensity. (Ɣ): J max,on ,
(Ŷ): J max,off . The solid lines are the results of fitting the parameters of Eqs. (11), (15)
and (26) to the data with the following results: C m = 1 μF cm -2 (fixed), C p = 2 μF
cm -2 (fixed), G m = 10 nS cm -2 (fixed), G p = 1 μS cm -2 (fixed), J s p,0 = (930 r 30) nA
cm -2 , L 1/2 = (0.5 r 0.1), V * = (0.010 r 0.001) V. 107

( ii ) Influence of the Ionophore CCCP

We stated earlier that one of the advantages of nano-BLMs
over SSMs for monitoring light-induced bR-photocurrents lies in
the notion that nano-BLMs provide a second aqueous reservoir,
which should allow for observing stationary photocurrents. In or-
der to verify this hypothesis, the ionophore carbonyl-cyanide- m -
chloro-phenylhydrazone (CCCP), a proton gradient decoupler, 101
was used to permeabilise the nano-BLMs when PM-fragments
were adsorbed. During the course of illumination in the presence
of CCCP, a positive stationary photocurrent of a distinct value, de-
pending on the concentration of the ionophore, is detected ( Fig. 20
A ).