Nano-Structured Gas Sensing Materials for Ammonia Detection with Special Emphasis on Medical Applications

Ammonia, a highly toxic gas, known for its wide industrial usage, is now gaining importance as a biomarker for quite a few terminal diseases. Therefore, the quest for a sensitive and selective ammonia gas sensor is booming. A brief study on the importance and various sources of ammonia gas has been recapitulated in this review along with the elaboration of ammonia as a biomarker for clinical applications embracing renal and hepatic diseases. In addition, developments in nanotechnology-based ammonia sensors have been summarized in-depth, emphasizing metal oxide semiconductor (MOS) based, polymer-based, and carbon nanomaterial-based gas sensors. This review has brought into the limelight the importance of sensing very low concentrations of ammonia. The performance of a wide range of MOS, polymer, and carbon nanomaterial-based sensors has been summarized in minute detail which will help researchers in attaining a quick analysis of state of art sensors to meet the needs of their intended application areas.