A single probe for solvent dependent optical recognition of iron(II/III) and arsenite: discrimination between iron redox states with single crystal X-ray structure evidence

The detection and discrimination of Fe 2+ and Fe 3+ ions have been investigated using a simple probe (L), produced by the condensation of ethylenediamine and 3-ethoxysalicyaldehyde. Single crystal X-ray structures demonstrate that L interacts with Fe 2+ and Fe 3+ . In aqueous-DMSO media, the L recognises AsO 2 − by fluorescence and colorimetry techniques. The AsO 2 − aided PET inhibition and H-bond assisted chelation enhanced fluorescence (CHEF) boost fluorescence by 91-fold. The L can detect 0.354 ppb Fe 2+ , 0.22 ppb Fe 3+ and 0.235 ppt AsO 2 − .