Potentiometric phosphate-sensing system utilizing phosphate-binding protein

Abstract. A phosphate-detection system has been developed which uses phosphate-binding protein (PBP) from Escherichia coli. PBP was immobilized on a sheet of nitrocellulose membrane by cross-linking and the membrane potential of the immobilized PBP was measured.. The response time of the system to phosphate was 5 min. The response was selective to phosphate among other anions. Under optimum conditions 0.1–1.5 mmol L–1 phosphate can be determined with this system.