High-sensitivity Mercury Ion Detection System Using Unmodified Gold Nanorods

Hg2+ is one of the most universal and severe toxic metal pollutants. Here we reported a high-sensitivity and rapid method for detection of Hg2+. The technique was based on the localized surface plasmon resonance property of gold nanorods. Neither modification of gold nanorods nor separation of analyte was necessary. The longitudinal absorption peak of gold nanorods presented a linear blue shift as Hg2+ concentration increased. The blue shift of longitudinal absorption peak was due to the changes of both aspect ratio and medium dielectric constant. The sensor had a wide linear interval ranging from 285 nM to 8.00 μM, the detection limit was as low as 112 nM, and the sensitivity was 30.48 nm μMμ1, which were comparable to the performance of the modified sensors.