Far Infrared Sensing Of The Oxidation State Of Heme Proteins

We propose a biosensor based on the change of terahertz (THz) dielectric response when a biotarget binds to a probe. The feasibility of this biosensor is examined by studying the change of THz transmission for thin films of heme proteins myoglobin (Mb) and cytochrome C (CytC) as a function oxygen binding. We measure a strong increase in both the index and absorbance with oxygen binding for both Mb and CytC. The measured changes occur for both dried and samples hydrated at 80% r.h. suggesting that using terahertz time domain spectroscopy (TTDS) to monitor the transmitted terahertz pulse through a biomolecular probe thin film in ambient environmental conditions could be used to determine the presence of a biomolecular target.