Mercury (II) sensor by forming Hg/Ag amalgam based on silver nanoparticles modified screen-printed carbon electrode

Abstract

The fabrication of a silver nanoparticles/chitosan/carbon nanotubes modified screen-printed carbon electrode (SPCE) as a highly sensitive platform for ultratrace mercury (II) detection was reported here. Silver nanoparticles (AgNPs) were synthesized by chitosan (CS) and carbon nanotube (CNT) hybrids with a green way. Chitosan trapped AgNPs anchoring on the sidewalls of the CNT arrange the nanoscale silver electrode arrays. Hg/Ag amalgam was formed on the surface of AgNPs/CS/CNT modified SPCE by depositing the mercury species to elemental mercury. Hg(II) detection is achieved by the stripping both Hg0 and Ag0 at +0.16V in the supporting electrolyte (0.1M HCl and 0.1 M KCl). This selective and sensitive detection method exhibits an excellent linear Hg(II) concentration range of 1.0 nM to 12.6 nM and a low detection limit of 0.4nM with R2 = 0.982 (n=13). The newly designed electrode has been successfully employed to measure Hg(II) in the textile samples with a good stability. The method demonstrates acceptable reproducibility and precision.