In recent years, non-invasive monitoring of biomarkers has become more important for prevention and early treatment of diseases. Sweat is a promising fluid for continuous detection of various analytes, being an easy-to-collect medium and containing electrolytes, proteins, and compounds such as ammonia. Ammonia is a byproduct of protein metabolism, and an excess of it can be an indicator of liver dysfunction, such as cirrhosis, liver cancer, or encephalopathy, so its monitoring is essential for health. Electrochemical wearable sensors are an optimal approach to monitor biomarkers in real time because of their ability to provide continuous data on physiological status using conductive electrodes and selective detection techniques.