Transcription factor-based biosensor for detection of phenylalanine and tyrosine in urine for diagnosis of phenylketonuria.

Clinicians require a simple quantitative method for the detection of both phenylalanine and tyrosine to facilitate the diagnosis of phenylketonuria, a common inherited disorder of amino acid metabolism. In this study, we developed a novel whole-cell biosensor for the quantification of phenylalanine and tyrosine through the expression of red and green fluorescent proteins. The proposed system responds specifically and sensitively to phenylalanine/tyrosine without interferences from other amino acids. Furthermore, the precision of the biosensor was evaluated using specimens of normal human urine by LC-MS.