[60]Fullerene immobilized in a thin functionalized polypyrrole film. Basic principles for the elaboration of an oxygen sensor

[60]Fullerene, entrapped in a thin polymer film synthesized by oxidative electropolymerization on a layer of an amphiphilic pyrrole derivative mixed with the fullerene and coated onto an electron-conducting substrate, was shown to play the role of a modified photoelectrode. The photocurrents obtained upon irradiation with visible light in the presence of a water soluble electron donor were shown to be very sensitive to the presence of oxygen in the vicinity of the modified electrode, especially at low oxygen concentrations. This behaviour is explained by the competition between the deactivation of the photoexcited states of [60]fullerene by electron transfer from the donor and by energy transfer to molecular oxygen. This basic principle for the design of a new oxygen sensor is discussed.