Volume 92, Issue 5, 01 September 2002
Index of content:
- APPLIED BIOPHYSICS (PACS 87)
Electric conductivity of dye modified DNA films with and without light irradiation in various humidities92(2002); http://dx.doi.org/10.1063/1.1498959View Description Hide Description
Dye-DNA complex film was prepared by modifying DNA with acridine orange (AO) and depositing it on goldelectrodes having a gap in the order of micrometers. Measurement of the electrical characteristics of the dye-DNA film was performed in a vacuum and in various humidities. A photoinduced conductivity change, which we suggest is caused by band or hopping conduction, was observed at relatively low humidity (20%) and in a vacuum. As the humidity rises to 70% and above, the current jumps from picoampere to milliampere levels. This dramatic resistance change corresponds to a dominant conductor mechanism change from hopping or band conductivity to ion conductivity. These reproducible characteristics of photoinduced and humidity-dependent conductivity suggest that the AO-DNA setup could be used as a photosensitive semiconducting device and as a humidity sensor chip.