Highly sensitive fluorescent sensor for mercury based on hyperbranched rolling circle amplification.

A label-free hyperbranched rolling circle amplification (HRCA) based fluorescent sensor has been developed for Hg(2+) detection. The fluorescence intensity has a linear relationship with the concentration of the target in the range of 0.425 pmol L(-1) to 42.5 nmol L(-1), and the detection limit is as low as 0.14 pmol L(-1) (S/N = 3). The proposed sensor had been applied to detect Hg(2+) in water samples with satisfying results.