Fluorometric Sensor for Mercury Ion Detection in a Fluidic MEMS Device

Mercury (Hg
²⁺
) ion is one of the heavy metal ions present in water and highly poisonous to human consumption. Thus, developing an efficient sensor for detection of mercury ions at different concentration levels in the water down to nM is essential. Here, we report the development of fluorometric sensor using the fluidic MEMS device (i.e., microfluidic device) with high sensitivity and selective detection of Hg
²⁺
in water using tiny quantity of sensing fluids (~2.8 μL). L-Arginine-capped gold nanoparticles functionalized with Rhodamine 6G allowed the on-chip fluorescence detection of Hg
²⁺
ions concentration regime from 0 to 16 nM in water samples. The developed microfluidic device senses the presence of Hg
²⁺
ions through the change in intensity of fluid fluorescence. The sensor response is found to be linear with respect to the Hg
²⁺
ions concentration ranging from 2 to 12 nM.