A Novel Single-Labeled Fluorescent Oligonucleotide Probe for Mercury(II) Ion Detection: Using the Inherent Quenching of Deoxyguanosines

A novel single-labeled fluorescent oligonucleotide (OND) probe for the detection of nanomolar mercury(II) ion in aqueous solution is developed based on the inherent quenching of deoxyguanosines. The formation of hairpin structure of OND-Hg2+ complex brings deoxyguanosines close to dye, resulting in decreased dye fluorescence due to photoinduced electron transfer from dye to deoxyguanosines.