Fluorescence quenching by complex of a dna aptamer and porphyrin for sensitive detection of porphyrins by capillary electrophoresis

Here, we used a fluorophore-bound, porphyrin-targeted DNA aptamer to increase the sensitivity of capillary electrophoresis for the detection of a model porphyrin. The complex of the DNA aptamer with the porphyrin induced the transfer of energy from the fluorophore to the porphyrin, resulting in the quenching of fluorescence. Monitoring of the quenching of fluorescence by capillary electrophoresis allowed the model porphyrin to be detected at sub-nanomolar concentrations, which is a marked improvement over conventional direct-detection capillary electrophoresis approaches.