Highly sensitive and selective detection of silver(I) ion using nano-C60 as an effective fluorescent sensing platform.

In this Communication, we report water-soluble nano-C(60) in the first use as an effective fluorescent sensing platform for the highly sensitive and selective detection of Ag(+). The general concept used in this approach is based on a fluorescently labeled single-stranded DNA (ssDNA) probe that adsorbs on nano-C(60), leading to substantial dye fluorescence quenching; however, in the presence of Ag(+), C-Ag(+)-C coordination induces the probe to fold into a hairpin structure, which does not adsorb on nano-C(60) and thus retains the dye fluorescence. This sensing system exhibits a detection limit as low as 1 nM and has a high selectivity against other metal ions. Finally and most importantly, we demonstrate its performance in real sample analysis.