Point-of-care (POC) application for monitoring of breath ammonia (BA) in hemodialysis patients have emerged as a promising non-invasive health monitoring approach. In this context, many organic gas sensors have been reported for BA detection. However, one of the major challenges for its integration with portable POC application is to achieve long lifetime and high operational current at low voltage. Herein, we propose a double active layer (DL) strategy that exploits an ultra-thin layer of Poly(3hexylthiophene-2,5-diyl) (P3HT) to serve as a work function buffer, combined with an acceptor-donor polymer Poly [[4,8-as a new sensing material. We show that the DL sensor exhibits a sustainable enhanced operational current of microampere level and a stable sensing response even with the presence of P3HT layer. This effect is carefully examined with different aspect, including vertical composition profile of DL configuration, lifetime testing on different sensing layer, morphological analysis, and the versatility of the DL strategy. Finally, we utilize the CT/P3HT-DL sensor to conduct a long-term tracing of BA concentration in two hemodialysis (HD) patients before and after HD, and correlate it with the blood urea nitrogen (BUN) levels. A good correlation coefficient of 0.96 is achieved. The result demonstrates the potential of this DL strategy to be used to integrate organic sensor in POC devices.