This technology includes the development of devices capable of real-time evaluation of metabolite levels for the treatment of numerous metabolic disorders, including hyperammonemia and aminoacidopathies. Currently, the monitoring of metabolite levels is done in a hospital setting with specialized mass spectrometry instrumentation. As a consequence, susceptible patients who are undergoing a crisis need to visit the hospital for testing to determine if there is a metabolite disturbance. The development of a device, including an electrode with immobilized enzymes, could transform the care of these metabolite disorders similar to insulin detection and diabetes.