Prototype development of paper based sensor for ammonia detection in water

The presence of ammonia in water supply can be dangerous to human health. This is because the ammonia not easily detected and the cost of the existing ammonia detector is quite expensive. The existing method of detection and monitoring of ammonia with chemical approach is time consuming, thus, electrical-based is recommended. The sensor device was developed in this project utilizing bio-environmentally friendly material such as paper and graphite. The different type of paper and graphite was used in this project to evaluate the sensitivity and selectivity of sensor. A suitable pattern was defined as the sensing area for detected the presence of ammonia in water. The device was connected with a constant voltage to generate the current flow through electrode that made of graphite and the sample was tested by drop onto the sensing area. As the result, the current changes were detected with presence of ammonia in water. A zinc oxide layer was proposed to be added at the sensing area for sensor enhancement. It is found that the presence of zinc oxide can improve the sensitivity of sensor by faster detecting the sample drop on the sensing area compare to the graphite with shorter time response characteristics