Quartz crystal microbalance sensor based on affinity interactions between organic thiols and molybdenum disulfide nanoparticles

Molybdenum disulfide nanoparticles have been synthesized for the sensing of thiol vapors in air based on affinity interactions. Purity of MoS2 nanoparticles was confirmed by X-ray diffraction (XRD) analysis and the particle size was determined by atomic force microscopy (AFM). In the current study, the relationship between nanoparticles size and sensitivity is investigated. The sensitivity of the sensor is linearly correlated to particle diameters. Newly fabricated sensors show detection limits of 30 ppm for 1-butanethiol and less than 0.5 ppm for 1-octanethiol. Furthermore, they exhibit minimal cross-reaction towards alkanes (2 Hz response at 500 ppm n-octane). They exhibit linear response behavior towards different concentrations of thiol. Furthermore the MoS2 nanoparticles based system was optimized regarding to sensitivity, selectivity and influence of layer parameters on the sensor signals.