A recyclable polyoxometalate-based supramolecular chemosensor for efficient detection of carbon dioxide

A new type of supramolecular chemosensor based on the polyoxometalate (POM) Na(9)DyW(10)O(36) (DyW(10)) and the block copolymer poly(ethylene oxide-b-N,N-dimethylaminoethyl methacrylate) (PEO(114)-b-PDMAEMA(16)) is reported. By taking advantage of the CO(2) sensitivity of PDMAEMA blocks to protonate the neutral tertiary amino groups, CO(2) can induce the electrostatic coassembly of anionic DyW(10) with protonated PDMAEMA blocks, and consequently trigger the luminescence chromism of DyW(10) due to the change in the microenvironment of Dy(3+). The hybrid complex in dilute aqueous solution is very sensitive to CO(2) content and shows rapid responsiveness in luminescence. The luminescence intensity of the DyW(10)/PEO-b-PDMAEMA complex increases linearly with an increasing amount of dissolved CO(2), which permits the qualitative and quantitative detection of CO(2). The complex solution also shows good selectivity for CO(2), with good interference tolerance of CO, N(2), HCl, H(2)O and SO(2). The supramolecular chemosensor can be recycled through disassembly of the hybrid complex by simply purging with inert gases to remove CO(2).