A novel proteinase K biosensor based on interdigitated conductometric electrodes for proteins determination in rivers and sewers water

The traditional systems of analysis are not any more in adequacy with the new needs, such as in situ control of pollution (industrial wastes, heavy metals, quality of water) or in vivo measurements in the biomedical field. With approximately 30% of the total chemical oxygen demand (COD), the proteins are the major fraction of the organic matter of the effluents. For this reason, a conductometric enzyme biosensor based on a proteinase K was developed and then tested with real samples of water from rivers and sewers. The biosensor was optimized with the bovine serum albumin (BSA) as a standard protein. A good reproducibility and high storage stability (more than 1 month) are observed. A large linear range of response for BSA determination from 0.4 to 8 mg/l was obtained. The results given by the biosensor for water analysis are, qualitatively, in adequacy with those given by the colorimetric method using the bicinchroninic acid.