Simultaneous detection of CMPA and PMPA, hydrolytes of soman and cyclosarin nerve agents, by nanopore analysis

A sensitive nanopore-based analytical method was developed for the detection of cyclohexyl methylphosphonic acid (CMPA) and pinacolyl methylphosphonate (PMPA), hydrolytes of nerve agents soman and cyclosarin, respectively. The method uses a multi-functionalized α-hemolysin protein ion channel as the sensing element, with a host molecule β-cyclodextrin lodged in the lumen of the channel as a molecular adapter. The capture and release of CMPA/PMPA by the β-cyclodextrin host caused current modulations in the nanopore. Since the event residence times and amplitudes were significantly different, CMPA and PMPA could conveniently be differentiated and simultaneously quantitated.