Advanced functional rGO@MoS2@PEDOT: PSS multicomponent-based nanocomposite films for rapid and ultra-sensitive TNT detection

Abstract

Ultra-sensitive and highly selective detectors are attracting increasing attention to combat any undesired terrorist activities. High sensitivity and selectivity are the two major concerns for the development of the sensor for explosive detection. Herein, 2,4,6 TNT explosive sensor based on multicomponent nanocomposite film (Mc-NFs) is fabricated through an interface modulation technique. The Mc-NFs, porphyrin functionalized rGO@MoS2 @PEDOT: PSS (TPP-rGO@MoS2 @PEDOT: PSS) films, exhibit excellent selectivity and ultra-sensitivity towards TNT vapor at room temperature with outstanding sensing response (246% for 1.5 ppb), a rapid response time (3.5 s). The obtained results reveal the synergistic actions of the individual sensor components, where the rich active sites of MoS2 are playing a major role in high sensing response, π-π interactions between TPP-rGO and TNT lead to rapid adsorption/desorption of TNT vapors, and PEDOT: PSS assures the homogenous dispersion of the components in the sensor film. Further, the film exhibits excellent selectivity towards highly oxidizing TNT vapors due to strong N-type nature of the film along with the functionalization of rGO with porphyrin. The sensor has also been investigated for different concentrations of TNT vapors in the concentration range of 1.5–47ppb, showing an average rapid response time of 2 s, and recovery time of 42.5 s. The sensor has a high sensitivity of 4.09% /ppb, remarkable linearity (R-value > 0.976), good reproducibility and repeatability, low limit of detection (0.1 ppb), and good sensing stability. The prepared TPP-rGO-10%@MoS2-5%@PEDOT: PSS film has the potential to be used as an ultra-sensitive TNT detector in handheld devices.