• An inability to be steam sterilized
  
• They react with the product
  
• And are oversensitive
  

1.) Microbial sensors consisting of immobilized whole cells and an oxygen probe when used for determination of substrates and products. The concentration of compounds was determined from microbial respiration activity which could be directly measured by an oxygen probe.

2.) Microbial sensor consisting of immobilized microorganisms and an electrode was used for determination of organic compounds. The concentraion of compounds was indirectly determined from electroactive metabolites such as proton, carbon dioxide, hydrogen, formic acid, and reduced co-factors which can be measure by the electrode.

Bionsenors for Nutrients:

• Glucose Sensor
  

Bionsenors for Cell Population:

• Lactate Sensor
  

Bionsenors for Products:

• Alcohol Sensor
  

Bionsenors for Environmental Control:

• Biochemical Oxygen Demand Sensor
  

This text was written by Craig Pohan and Matt Armstrong at Rensselaer Polytechnic Institute (c) 1995