Unique norbornene polymer based in-field sensor for As(III)

We report the synthesis of norbornene derived rhodamine (Nor-Rh) and thiol (Nor-Th) monomers and their polymerizations. The response of Nor-Rh against As(III) in the presence of potassium iodate and hydrochloric acid is monitored through UV and fluorescence spectroscopy. The observed colorimetric as well as fluorometric changes are attributed to the redox reaction involved in the unique design. Cyclic voltammogram measurements confirm the oxidation of As(III) to As(V) during the sensing event. The response of the sensing event is instantaneous. This novel design is able to sense ppb levels of As(III) very selectively in an aqueous environment. As(III) is trapped when it is passed through a column containing Nor-Th polymers. As(III) free water is tested using a calibration curve from the Nor-Rh response.