A simple fluorescent assay for lead(II) detection based on lead(II)-stabilized G-quadruplex formation

A fluorescence quenching result was obtained when an FAM-labelled G-rich oligonucleotide T30695 was treated with Pb2+, owing to the formation of a lead(II)-stabilized G-quadruplex. Based on this phenomenon a selective fluorescent assay for lead(II) detection with a limit of detection of 0.77 ppb and a detection range from 0 to 200 ppb was constructed.