Design of ultrasensitive DNA-based fluorescent pH sensitive nanodevices.

Here we tune the pH sensitivity of a DNA-based conformational switch, called the I-switch, to yield a set of fluorescent pH sensitive nanodevices with a collective, expanded pH sensing regime from 5.3 to 7.5. The expanded pH regime of this new family of I-switches originates from a dramatic improvement in the overall percentage signal change in response to pH of these nanodevices.