Portable mercury sensor for tap water using surface plasmon resonance of immobilized gold nanorods

The surface plasmon resonance of surface immobilized gold nanorods (Au NRs) was used to quantify mercury in tap water. Glass substrates were chemically functionalized with (3-mercaptopropyl)trimethoxysilane, which chemically bound the nanorods to produce a portable and sensitive mercury sensor. The analytical capabilities of the sensor were measured using micromolar mercury concentrations. Since the analytical response was dependent upon number of nanorods present, the limit of detection was 2.28×10−19 M mercury per nanorod. The possibility to using glass substrates with immobilized Au NRs is a significant step towards the analysis of mercury in tap water flows at this low concentration level.