The real-time detection of trace-level Hg2+ in water by QCM loaded with thiol-functionalized SBA-15

Thiol-functionalized SBA-15 mesoporous silica materials with various pore sizes and specific surface areas were prepared by using a post-grafting process. All the obtained materials were characterized by SAXS, FT-IR, TGA, TEM and N2 adsorption isotherms. By using these functionalized mesoporous silica as sensing materials, the QCM sensor was constructed and used for detecting heavy metal ions. The experimental results indicated that the QCM sensor can detect 1 ppm Hg2+ with the response frequency of 175 Hz in the response time of 1 min. The influence of response time, the amount of thiol groups, pore size and specific surface area of SBA-15 mesoporous silica on Hg2+ detection was studied systematically in this paper.