Polypyrrole colloidal nanospheres as an effective fluorescent sensing platform for DNA detection

In the present study, we demonstrate the first use of polypyrrole colloidal nanospheres (PPyCNPs) as an effective sensing platform for fluorescence-enhanced DNA detection by the following two steps: (1) PPyCNP adsorbs and quenches a dye-labeled single-stranded DNA (ssDNA) probe; (2) The subsequent hybridization of the probe with its target produces a double-stranded DNA (dsDNA) which detaches from PPyCNP, leading to recovery of dye fluorescence. The present system shows a detection limit as low as 1 nM and has a high selectivity down to single-base mismatch.