Graphene oxide for high sensitivity detection of 2,4-Dinitrotoluene by developing of a heat absorption monitoring sensor

Abstract

In this paper, a Graphene-Oxide Heat Absorption Monitoring (GO-HAM) sensor is designed and fabricated for high sensitivity detection of 2,4-Dinitrotoluene (DNT). The calculations based on Density Functional Theory (DFT) demonstrate that DNT molecules tend to be physisorbed onto the GO. Hence, the GO is synthesized by an oxidative treatment of purified graphene using the modified Hummers method (MHM) and implemented on the sensor. The temperature and relative humidity of the testing setup are 40 °C and 45%, respectively, and the test results show that the GO-HAM sensor, heated up to the melting point of DNT (70 °C), can detect DNT about 4.6 ppb. These results indicate that the limit of detection (LOD) has modified 3.25 times compared with the bare HAM sensor. Moreover, the results show that the fabricated sensor has high repeatability, and also it has good selectivity to DNT compared with acetone. Therefore, the implementation of GO on the sensor surface enhances the absorption ability and sensitivity of the sensor due to the physisorption of DNT molecules onto GO and a large surface to volume ratio of GO.