Fluorene‐Labeled 2'‐Deoxyuridine as an Environmentally Sensitive Probe for Detection of an Abasic Site

Abstract The fluorescence properties of the fluorene‐labeled 2'‐deoxyuridine derivative U F are sensitive to the polarity and viscosity of its solvent. We incorporated this environment‐sensitive unit into the central position of oligodeoxynucleotides (ODNs) and placed various flanking bases (FBs) around the U F residue, then investigated the changes in fluorescence that occurred when these ODN probes encountered DNA targets containing an abasic site. The ODN probe featuring cytosine‐FBs turned on its fluorescence when contacting the fully matched target DNA sequence, but turned off its fluorescence dramatically when the target DNA contained an abasic site.