The use of ammonia as a green fuel for power generation and energy storage is increasing rapidly for both vehicles and large-scale power plants. Hence, there is a growing demand for ammonia sensors in safety and health monitoring, which would lead to a serious waste-recycling challenge. Besides, the current conversional ammonia sensors require a high operating temperature, resulting in high power consumption. Herein, a biodegradable film utilizing a colorimetric platform is proposed to offer excellent zero and near-zero power ammonia sensing at room temperature. In this work, the colorimetric ink is fabricated via the amalgamation of commercially available dyes and sodium carboxymethyl cellulose matrix, followed by spin coating it on cellulose tape to obtain a flexible colorimetric film. With the weight ratio of bromophenol blue to bromocresol green at 2:1, the fabricated film exhibits the largest bathochromic shift of 190 nm on the main absorption peak and an uppermost total color change of 85.701 upon exposure to 450 ppm ammonia. The rapid color response of the fabricated film from yellow to blue within 5 seconds under an ammonia environment with a protracted recovery time of 5 minutes is capable of being distinguished by the naked eyes as a zero-power ammonia sensor. Additionally, the fabricated film integrated with a commercial ultra-low power microchip for continuous real-time monitoring and Internet of Things applications showed a discernible optical reflective signal upon exposure to ammonia. This study explores feasible and rapid ammonia sensing at zero and near-zero power using biodegradable materials. [ABSTRACT FROM AUTHOR]