Mercury(II) sensors based on calix[4]arene derivatives as receptor molecules

Mercury(II) sensors prepared by incorporating three different calix[4]arene derivatives as neutral receptor molecules showed near-Nernstian slopes within wide linear concentration ranges and low detection limits of order ∼10−6 M. The sensors were found to work well in the pH range of ∼1.0–4.0 with response time of less than 20 s and showed reproducible and stable potentiometric signals. The selectivity coefficient values showed better sensitivity and selectivity of these sensors for mercury(II) ions over various mono-, di, trivalent cations studied. The sensors were also applied as indicator electrodes in the potentiometric titrations and successfully used to determine mercury(II) ions in synthetic samples.