Acknowledgements: Dr. Ray thanks NSF-PREM grant # DMR-0611539, NSF-CRIFMU grant # 0443547 and ARO grant # W911NF-06-1-0512 for their generous funding
Contamination of the environment with mercury has been an important concern throughout the world for decades. Human exposure to high Hg 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 mercury 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 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 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.