By incorporating a synthetic DNA sequence in a polyacrylamide hydrogel, a new nanomaterial able to measure very low concentrations of mercury in water samples was developed. Next, the new material was incorporated in a Diffusive Gradient in Thin Film (DGT) holder to produce a cost-effective, easy-to-operate, field-deployable DGT-DNA sensor for aqueous mercury(II), which requires no sample preparation. The performance of the DNA-DGT sensor was assessed under variable pH (3–10) and temperature (5–40 °C) conditions, as well as across a range of hydrochemically diverse artificial and natural freshwaters. The results support the use of the new DNA-DGT sensor as an alternative to traditional sampling and analysis methods for determining aqueous mercury(II) concentrations down to the nano molar level in freshwater environments. The research was carried out by ERG member Kunfu Pi (now an associate professor at China University of Geosciences) in collaboration with Philippe Van Cappellen from ERG and Juewen Liu of the Department of Chemistry.
The paper can be accessed via this link.