Highly Sensitive Hybrid Nanostructures for Dimethyl Methyl Phosphonate Detection

Abstract

Nanostructured materials synthesized by the hydrothermal and thermal reduction process were tested to detect the dimethyl methylphosphonate (DMMP) as a simulant for chemical warfare agents. Manganese oxide nitrogen-doped graphene oxide with polypyrrole (MnO2@NGO/PPy) exhibited the sensitivity of 51 Hz for 25 ppm of DMMP and showed the selectivity of 1.26 Hz/ppm. Nitrogen-doped multi-walled carbon nanotube (N-MWCNT) demonstrated good linearity with a correlation coefficient of 0.997. A comparison between a surface acoustic wave and quartz crystal microbalance sensor exhibited more than 100-times higher sensitivity of SAW sensor than QCM sensor.

Nano-Sheet-like Morphology of Nitrogen-Doped Graphene-Oxide-Grafted Manganese Oxide and Polypyrrole Composite for Chemical Warfare Agent Simulant Detection

“…The response times ( T 90 ) can be explained as the time taken to attain 90% of the equilibrium, whereas the recovery time is the time taken to reach 10% of the equilibrium via purging with the dry nitrogen [ 67 ]. Figure S15 illustrates the response and recovery time of the hybrid composites.…”

“…For both the composites, the recovery times were longer than the response times. The reversible response also indicates that the adsorption of DMMP onto the sensing materials consists of weak hydrogen bonding or Van der Waals forces [ 67 , 68 ]. The performance comparison was conducted with a composite-material-coated QCM sensor for the detection of DMMP as shown in Table S3 .…”

Synthesis and Characterization of MnO2@Cellulose and Polypyrrole-Decorated MnO2@Cellulose for the Detection of Chemical Warfare Agent Simulant

“…Hence, it may have caused the volumetric changes, allowing a small portion of the sensing material to fall off the CE surface [ 57 ]. The fast recovery of the QCM sensor when the QCM sensor was purged with nitrogen showed that the interaction between the sensing materials and DMMP was the weak force of attraction or hydrogen bonding [ 19 , 58 ].…”

“…The fabrication of the 250 MHz SAW sensor is reported elsewhere [ 10 , 19 , 40 , 41 ]. CE, MnO 2 @CE, and MnO 2 @CE/PPy were mixed with IPA at a 1 mg:7 mL ratio because SAW sensors are highly susceptible to the weight of the deposited sensing materials.…”

“…= 86.937 g/mol) with a density of 5.0 g/cm 3 has a decomposition temperature of 535 °C [ 11 ]. Because of their surface and electronic properties and the gas adsorbent capacity, manganese oxides are used widely in various fields, such as supercapacitors [ 12 ], batteries [ 13 ], water treatment [ 14 ], catalysts [ 15 ], decomposition [ 16 ], adsorption [ 17 ], and gas detection [ 18 , 19 ]. Thomas et al demonstrated the use of TiO 2 @MnO 2 nanorod arrays in the microcantilevers to enhance the detection of CWAs and their simulant [ 20 ].…”