Biosensor for Detecting Odorous Compounds

The odor quantification of any environmental sample by use of either panel decisions or analytical instruments is difficult. This study employed a sensor system to detect different odorants. The system consisted of an individual sensor or an array of multisensors in which different synthesized protein analogs were coated onto the surface of piezoelectric electrodes. By monitoring the change in the resonant frequency, the concentration of the specific gas was quantified. The targeted odor pollutants included volatile compounds of ammonia, mercaptoethanol, methyl amine, acetic acid, and chlorobenzene as well as gaseous compounds of ammonia and methyl amine. The results indicate that there is a linear relationship between sensor responses and compound concentrations. These sensors can detect compound concentrations in the low ppmv ranges. The response time is rapid. However, the system is not completely reversible-i.e., sensor response did not revert to its original value because of incomplete desorption with odorless air. Nevertheless, the response of the module forms a unique fingerprint for each individual compound and for mixed compounds. But reliability, stability, durability, and implementation of the system await further investigation.