<p>Detection of the level of ammonia gas in exhaled breath provides non-invasive and fast diagnosis of kidney failure. Here, we fabricated room temperature and sensitive chemiresistive ammonia gas sensor by in situ electropolymerization and deposition of polypyrrole/sulfonated graphene oxide (PPy/SRGO) on/between gold interdigitated electrodes (Au-IDEs). The prepared sensors were characterized by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FT-IR). The fabricated ammonia gas sensor was tested at different operating temperatures (26–50°C) and we selected room temperature for simplifying operation (26°C). At this temperature, the sensor showed two linear ranges of 5–40 ppb (R² = 0.99) and 40–5000 ppb (R² = 0.98) with the detection limit of 2.7 ppb. The fabricated gas sensor showed good selectivity toward ammonia in comparison with&#xa0;different interfering gases like acetone, dibutylamine, ethanol, methanol, and humid air (RH = 86%). According to the exhaled breath analysis, the fabricated sensor can determine ammonia level in the patient with kidney failure compared with&#xa0;the healthy persons. The results are with a good linear correlation to the clinical blood test. So this study presents the facile, rapid, and sensitive measurement of ammonia gas in human exhaled breath as a non-invasive diagnosis of kidney disease.</p> Graphical Abstract <p></p>