Regenerable DNA-functionalized hydrogels for ultrasensitive, instrument-free mercury(II) detection and removal in water.
Mercury is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, new materials are required to not only detect but also effectively remove mercury from environmental sources such as water. We herein describe a polyacrylamide hydrogel-based sensor functionalized with a thymine-rich DNA that can simultaneously detect and remove mercury from water. Detection is achieved by selective binding of Hg(2+) between two thymine bases, inducing a hairpin structure where, upon addition of SYBR Green I dye, green fluorescence is observed. In the absence of Hg(2+), however, addition of the dye results in yellow fluorescence. Using the naked eye, the detection limit in a 50 mL water sample is 10 nM Hg(2+). This sensor can be regenerated using a simple acid treatment and can remove Hg(2+) from water at a rate of approximately 1 h(-1). This sensor was also used to detect and remove Hg(2+) from samples of Lake Ontario water spiked with mercury. In addition, these hydrogel-based sensors are resistant to nuclease and can be rehydrated from dried gels for storage and DNA protection. Similar methods can be used to functionalize hydrogels with other nucleic acids, proteins, and small molecules for environmental and biomedical applications.
Dave
Neeshma
N
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Chan
Michelle Y
MY
Huang
Po-Jung Jimmy
PJ
Smith
Brendan D
BD
Liu
Juewen
J
D000180:Acrylic Resins / Q000138:chemical synthesis / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D013941:Thymine / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D000099166:Polyacrylamides
D000180:Acrylic Resins; D004247:DNA; D020100:Hydrogels; D008628:Mercury; D013941:Thymine; D014867:Water; D014874:Water Pollutants, Chemical; D000099166:Polyacrylamides