A Novel Coupling-Activated GO Nanocomposites Based on Surface Acoustic Wave for Assessing Capture Molecules and Detection of Explosive Gases

Surface acoustic wave (SAW) technology has been widely used in the field of hazardous gas detection, but there are still many problems to be solved such as long response/recovery time, poor selectivity and repeatability. In this study, we evaluated the adsorption capacity of various explosive capture molecules using SAW devices and designed a sensing material for 2,4,6-trinitrotoluene (TNT) gas detection by coupling 4-aminothiophenol (PATP), which has the best adsorption capacity, to activated graphene oxide (GO) via a disulfide exchange scheme. The SAW sensor based on graphene oxide/2-(2-Pyridyldisulfide) ethylamine hydrochloride/4-aminothiophenol (GO/ PDEA/PATP) has a theoretical detection limit (DL) as low as 2.8 ppb, short response/recovery time (15/45 s < ), good repeatability, stability selectivity and interference immunity. The enhanced mechanism for its high sensitivity and selectivity detection for TNT is based on the formation of a "Meisenheimer" complex by multiple strong interactions between PATP and TNT. Of course, the formation of this complex also leads to incomplete recovery of the sensor in high TNT concentrations. The scientific findings of this work will provide new idea for exploring the next generation of acoustic gas-phase explosives sensors.