(280c) An Ammonia Sensor for a Handheld Analyzer for Non-Invasive, Real-Time Monitoring of Kidney and Liver Disorders

A small device that could reliably measure urine ammonia in either the outpatient or inpatient settings would have a myriad of clinical applications. Diagnosis and management of disorders that impact absolute or relative changes in renal excretion of ammonia, including conditions that alter systemic acid/base homeostasis and diseases of the kidney and liver, would be greatly aided by such a device. However, traditional practical and technical limitations of urine ammonia measurement have impeded the use of urine ammonia as a routinely employed biomarker. This project is focused on the development of analyzer technology directed at ammonia measurement and the implementation of this analyzer into a practical handheld device prototype. The proposed technology is based on a unique hybrid sensor array capable of quick, precise, and reliable measurement. The analyzer will be capable of being applied in two broad formats: 1) a handheld device for outpatient or inpatient applications requiring less frequent (e.g., daily) monitoring, and 2) a urinary catheter device for semi-continuous measurement for inpatient applications requiring intensive serial monitoring. The miniaturized, low cost, easy to use handheld device prototype will utilize solid-state electronics with a high level of integration. Furthermore, the prototype will connect wirelessly to a centralized data display and storage unit (e.g., cellular phone), allowing a clinician to easily track an individual or a group of patients. This work shows the prototype of the sensor, and its capability for ammonia quantification in biological samples in real-time scale. The sensor shows fast and reversible response.