A rapid,sensitive,selective and reliable strip assay based on DNA-functionalized gold nanoparticles for Hg~(2+) detection has been developed,with a detection limit 5 nmol/L.The measurement principle was based on thymine-Hg~(2+)-thymine(T-Hg~(2+)-T) coordination chemistry and streptavidin-biotin interaction.The major advantages of this assay are that results can be read visually without any instrument in less than 10 min and that it does not require any sample pretreatment. A rapid, sensitive, selective and reliable strip assay based on DNA-functionalized gold nanoparticles for Hg 2+ detection has been developed with a detection limit of 5 nmol / L. The measurement principle was based on thymine-Hg ~ (2 +) - thymine (T-Hg ~ (2 +) - T) coordination chemistry and streptavidin-biotin interaction. The major advantages of this assay are that the results can be read visually without any instrument in less than 10 min and that it does not require any sample pretreatment.