Synergy of Two Intermolecular Hydrogen Bonds Promotes Highly Sensitive and Selective Room-Temperature Dimethyl Methylphosphonate Sensing: A Case of rGO-Based Gas Sensors

Thedevelopment of room-temperature chemiresistive gas sensorswith low limit of detection, high sensitivity, and selectivity fordimethyl methylphosphonate (DMMP) detection remains a challenge. Herein,a synergy of the two intermolecular hydrogen bond-promoted approachwas proposed to fabricate a room-temperature DMMP sensor with enhancedperformances. As a proof of concept, ternary p-hexafluoroisopropanolphenyl (HFIP) functionalized polypyrrole-reduced graphene oxide hybrids(HFIP-PPy-rGO) were rationally designed. During the sensing process,rGO serves as a conductive carrier, ensuring that the sensors operateat room temperature, and both HFIP and PPy act as adsorption sitesfor DMMP through hydrogen bonding interactions. As expected, the HFIP-PPy-rGOsensor exhibits high selectivity and sensitivity to DMMP. Besides,the HFIP-PPy-rGO sensor also possesses excellent linear response toDMMP and long-term stability. Experimental results and quartz crystalmicrobalance measurements prove that the specific recognition of DMMPis realized by forming two intermolecular hydrogen bonds between HFIPand DMMP, as well as PPy and DMMP. Additionally, the introductionof HFIP groups also contributes to adjusting device conductivity,enhancing signal conversion function. To put the DMMP sensor intopotential practical application, the obvious sensing response to differentDMMP concentrations in soil was confirmed, and a wireless detectionsystem was built to realize real-time monitoring of DMMP concentrationsin the surroundings. Overall, this study provides a facile and practicalsolution for improving the sensing performance of room-temperaturesensors based on the hydrogen bond theory.