Highly sensitive large-area multi-layered graphene-based flexible ammonia sensor

The paper reports the development of a highly sensitive, flexible and low-cost ammonia sensor. The sensing element is based on the chemically derived multilayered graphene deposited on a 3-inch diameter filter paper. The sensing material was deposited on a filter paper because it is a flexible substrate and also reduces cost. Multilayered graphene was obtained by reducing the graphene oxide (GO) using glucose. The fabricated sensor showed sensitivity to detect ammonia concentration as low as 430 ppb. The response characteristics of the sensor as a function of ammonia concentrations (varying from 400 to 4000 ppm) is reported in the paper. It also describes the variation in the response characteristics in flat and bent positions of the sensors. The reproducibility of the sensor performance is also established by the results presented in the paper. (C) 2014 Elsevier B.V. All rights reserved.