Bare eye detection of Hg(II) ions based on enzyme inhibition and using mercaptoethanol as a reagent to improve selectivity

摘要: The authors describe a colorimetric method for the determination of Hg2+ ions based on inhibition activity enzyme urease. pH value solution increases when urease hydrolyzes urea, which can be visualized by adding indicator such as Phenol Red (PhR). Mercaptoethanol typical thiol is added to system improve selectivity because it binds metal and then - unlike mercaptoethanol complex does not inhibit Hence, color PhR turns from yellow pink becomes alkaline. complex, in contrast, strongly inhibits remains yellow. findings were used design photometric assay measurement ratio absorptions at 558 nm 430 nm. It has linear response over 25 40 nM concentration range 5 nM detection limit. This well below guideline values specified US Environmental Protection Agency World Health Organization drinking water (10 nM 30 nM, respectively). was employed samples spiked with 10 nM levels where changes still observed visually.