Highly sensitive, selective and stable multi-metal ions sensor based on ibuprofen capped mercury nanoparticles

We report a one pot synthesis of mercury nanoparticles (HgNps) from mercuric chloride using hydrazine as a reducing agent and ibuprofen to coat the particles. The particles were synthesized under various conditions of pH and varying mercuric chloride, hydrazine, ibuprofen and sodium hydroxide concentrations. Ibuprofen capped HgNps (Ibu-HgNps) were characterized by UV–visible spectroscopy, scanning transmission electron microscopy (STEM) and Fourier transform infrared (FT-IR) spectroscopy. The as prepared Ibu-HgNps were applied onto glassy carbon electrode (GCE) and used as voltammetric sensor for simultaneous determination of Zn(II), Cd(II), Pb(II) and Cu(II) ions. Response was linear in the range of 0.1–600 ppb with regression coefficients around 0.999 for all metals. The lowest detection limit (LDL) for Zn(II), Cd(II), Pb(II) and Cu(II) was 0.05 ppb, 0.042 ppb, 0.03 ppb and 0.035 ppb showing high reproducibility with relative standard deviation (RSD) of 3.8%, 1.35%, 1.62% and 3.55% respectively for 15 repetitive scans. The sensor was successfully used for monitoring Zn(II), Cd(II), Pb(II) and Cu(II) in various types of water samples.