The outcome of a representative fingerprint enhancement is
shown in Figure 1. Voltammetric responses of these laterally
inhomogeneous films were consistent with those widely reported
for laterally uniform films deposited on bare electrodes.The
presence of the initial sebaceous print (not shown) was visible
with the aid of suitable lighting and viewing angle, but details
could not be discerned at a level adequate to permit identification.
Although the fingerprint deposit clearly locally inhibits the
electrochemistry that underlies polymer deposition and redox
switching, it does not do so on the intervening inter-ridge areas,
where there is deposition of polymer that is addressable by the
underlying electrode. Figure 1 shows selected images captured
at applied potentials generating distinct film colors. More detailed
appraisal of the visual contrast manipulation was provided by video
imaging (capture rate 30 fps) under potentiodynamic conditions