Pattern-based detection of anion pollutants in water with DNA polyfluorophores

ions to provide affinity and responsiveness to anions. Seventeen anions were screened with the library under an epifluorescence microscope, ultimately yielding eight chemosensors that could discriminate 250 μM solutions of all 17 anions in buffered water using their patterns of response. This sensor set was able to identify two unknown anion samples from ten closely-responding anions and could also function quantitatively, determining unknown concentrations of anions such as cyanide (as low as 1 mM) and selenate (as low as 50 μM). Further studies with calibration curves established detection limits of selected anions including thiocyanate (detection limit ~300 μM) and arsenate (~800 μM). The results demonstrate DNA-like fluorescent chemosensors as versatile tools for optically analyzing environmentally hazardous anions in aqueous environments.