6 - Application of sensors

Polymer based ammonia gas sensor

Enzymatic biosensors are beginning to have further applications for the analysis of environmental contaminants in air, water, and soil. Contaminants such as heavy-metal ions, organophosphorous pesticides, and carbamates can be detected by enzymatic biosensors based on their inhibition effect on enzymatic reactions. For the operation, these sensor types need measurement media saturated with the substrate of the applied enzyme. Such enzyme types are useful for these sensor purposes that show reversible reaction with the inhibitor to be detected, or the enzyme can be refreshed easily for a subsequent measurement cycle.

Electronic noses are selective and sensitive systems based on n pieces of gas sensor elements of different behaviour and principal component analysis combined with neural network analysis. This is be basis of various "smell" recognition. The normalized sensor responses can provide an n-dimensional vector. Molecular classification mapping is a two-dimension projection of this n-dimensional space derived from sensing measurements.