A label free aptamer-based LPG sensor for detection of mercury in aquatic solutions

We demonstrate a label free fiber optic sensor for detection of mercury ions in aquatic solutions. This sensor utilizes aptamers as bio-recognition element which traps mercury ions and cause a refractive index change in the vicinity of the sensor. Refractive index variations lead to a change in the transmission spectrum that can be used to calculate the concentration of mercury ions in that solution. The concentration of 1 nM mercury ions was detected which is below the specific amount determined by the US environmental protection agency as the maximum authorized contaminant level of Hg2+ ions in drinking water.