Designing label-free DNA sequences to achieve controllable turn-off/on fluorescence response for Hg2+ detection

Controllable turn off/on fluorescent sensors for Hg2+ detection were developed by designing different label-free DNA sequences and using the minor groove dye of DAPI. These assays exhibit high sensitivity and selectivity, with the detection limits of 5 nM and 1.5 nM for turn off and turn on sensors, respectively.