NSET, nano probe, gold nanoparticle, mercury detection, arsenic detection, environmental samples
Contamination of the environment with toxic metals like mercury and arsenic have been an important concern throughout the world for decades. Human exposure to high Hg or As levels can harm the brain, heart, kidneys, lungs, and immune system of people of all ages. Driven by the need to detect trace amount of toxic from environmental samples, here we present miniaturized, inexpensive and battery operated ultra-sensitive gold nanoparticle based nanomaterial surface energy transfer (NSET) probe for screening mercury and arsenic levels in contaminated soil, water and fish which has excellent sensitivity (2 ppt) and selectivity for Hg(II) over competing analytes, with the largest fluorescence enhancement to date for sensing Hg(II) in environmental samples (1100-fold). The sensitivity of our probe to detect mercury and arsenic level in soil, water and fish is about 2-3 orders of magnitude higher than the EPA standard limit. We demonstrated that our probe is suitable to screen amount of mercury in different commercial fish, shellfish and water from different sources.