[Development of conductometric biosensor based on alkaline phosphatase for determining concentration of cadmium ions].

The paper describes a novel conductometric biosensor sensitive to cadmium ions based on alkaline phosphatase immobilized on gold planar microelectrodes used as transducers. Assays have been carried out with paranitrophenyl phosphate as substrate for the immobilized enzyme. Various parameters such as reticulation time, along with pH, ionic strength and buffer concentration of the measuring solution were studied. The optimized biosensor was stable, reproducible and it exhibited a detection limit of 4.45 microM for cadmium ions.