A flow injection creatinine analyzer based on creatinine deiminase, leucine dehydrogenase and L-amino acid oxidase

Abstract

Many biological nitrogen compounds of analytical interest, such as creatinine, urea, and a number of L-amino acids, can be enzymatically deaminated to form ammonia. On the other hand, ammonia exists endogenously in almost all biological fluids. The key point to develop biosensors for the assay of such substances, therefore, is the selective detection of ammonia and overcoming the problem of endogenous ammonia. Because of the non-selectivity of the well used potentiometric detection using ammonia electrode, amperometric determination system is desirable.