Biosensors: recent trends

One of the major bottlenecks in automation and process control of industrial bioprocesses is the lack of suitable sensing devices to accurately measure the concentrations of biomolecules. The measurement of ions (e.g., H(+), NH(4)(+)) and gases (e.g., O(2), CO(2), NH(3)) using standard ion-selective and gas sensing electrodes respectively, is well established. Chemical analysis of biomolecules off-line is generally unreliable, labour intensive and may lead to contamination of the biological systems. Problems of maintaining sterile conditions are especially important when dealing with slow growing mammalian or plant cells in culture. Active research in the development of biosensors for monitoring fermentation processes, food production and pollution control, and for medical and veterinary applications is currently underway. This paper reviews recent approaches toward the development of biosensors which involve a biochemical interaction to measure the concentrations of biomolecules, primarily for the on-line monitoring and control of fermentation processes.