Bioinspired detection of light using a porphyrin-sensitized single-wall nanotube field effect transistor

Single-wall carbon nanotube ( SWNT) field effect transistors ( FETs), functionalized noncovalently with a zinc porphyrin derivative, were used to directly detect a photoinduced electron transfer ( PET) within a donor/acceptor ( D/A) system. We report here that the SWNTs act as the electron donor and the porphyrin molecules as the electron acceptor. The magnitude of the PET was measured to be a function of both the wavelength and intensity of applied light, with a maximum value of 0.37 electrons per porphyrin for light at 420 nm and 100 W/m(2). A complete understanding of the photophysics of this D/A system is necessary, as it may form the basis for applications in artificial photosynthesis and alternative energy sources such as solar cells.