Ultraviolet driven negative current and rectifier effect in self-assembled green fluorescent protein device

UV induced negative current produced at low voltages is reported in a photocurrent rectifier device consisting of a sensing region between two nano Al∕Al2O3 electrodes placed 30nm apart, employing a droplet of enhanced green fluorescent protein as molecular electrolyte. The current-voltage characteristics are discussed in terms of the properties of the thin Al2O3 scale, the position of the Fermi level, the position of the highest occupied molecular orbital-lowest unoccupied molecular orbital gap, and dispersion of states induced by varying dielectric constants.