A molecular imprinted polymer (MIP) fabricated from a biomaterial (chitosan) was successfully created for the selective trapping of dimethyl methylphosphonate (DMMP) in the thousands of parts per million. DMMP is an organophosphorus compound that can be used in the production of chemical weapons and is the accepted surrogate to test filters and protective clothing designed to trap organophosphorus compounds. Computational calculations (density functional theory: B3LYP/6-31G) were used to calculate the optimum ratio of chitosan to DMMP that would produce the most energetically stable template–monomer complex. Gas chromatography mass spectrometry was used to model the DMMP concentration in the gas phase and to determine the DMMP trapped by the MIP, non-imprinted polymer (NIP), and activated charcoal. The MIP trapped 4554 (±227) ppm (4.55 mg/g) DMMP and outperformed both the NIP (156 (±20) ppm (0.16 mg/g)) and activated charcoal (82 (±17) ppm (0.08 mg/g)). Acetic acid, ammonium hydroxide, acetone, ethanol, and 2-propanol were introduced into the system as interferents and did not significantly affect the amount of DMMP trapped by the MIP: 4286 (±74) ppm (4.29 mg/g). Reusability of the MIP is affected by the extraction process but does not significantly affect the intended use as a filter for hazardous materials. Scanning electron microscopy was used to study the surface morphology of the MIP, and after MeOH extraction, the surface of the MIP became coarser, illustrating the alteration of the material. Overall, the trapping capabilities of the MIP are far superior to activated charcoal 50-fold and can be used as a filling agent in gas masks or gas filters.

The use of chemical warfare agents (CWAs) remains a real threat to public life, in order to safeguard and protect lives. Continues research and investment need to make into early warning systems. Within the scientific literature several sensors have been produced for the detection of CWAs and organophosphorus compounds with varying sensitivities and selectivity. Most sensors developed are unable to detect below the minimum risk level, rendering them ineffective for early warning systems. The use of molecularly imprinted polymers (MIPs) to increase the sensitivity of the sensor is a possible solution to this problem. For an MIP to be successful, the correct monomer must be selected that is complementary to the chosen template molecule. This study utilises computational chemistry for the identification of potential monomers complementary to the chosen template, for the fabrication of an MIP. Dimethyl methylphosphonate (DMMP) was used as the template for the MIP as the compound is a mimic for Sarin and is used heavily within the literature for the design of chemical warfare sensors. By investigating the polymerisation capabilities and interactions with the template, a suitable candidate can be selected without wasting time and resources. The chemical structures of the monomers and template were imported into Spartan and converted into a 3D model. Density functional theory (DFT) with the B3LYP/6-31G level was used to calculate the electronic binding energies with a 1 to 3 ratio of Chitosan to DMMP proving to be the most efficient option.