Color is everything: Hg 2+ in aqueous media is detected by the formation of thymidine-Hg 2+-
thymidine coordination complexes, which raises the melting temperature of the DNA-
hybridized gold nanoparticle probes and thus the temperature at which the probes disperse
and effect a purple-to-red color change. The method has very high sensitivity and selectivity,
and it provides a simple and fast colorimetric readout (see picture).(Figure Presented)

Mercury is a widespread pollutant with distinct toxicological profiles, and it exists in a variety
of different forms (metallic, ionic, and as part of organic and inorganic salts and complexes).
Solvated mercuric ion (Hg2+), one of the most stable inorganic forms of mercury [1], is a
caustic and carcinogenic material with high cellular toxicity [2].