Iron-doped cerium/nucleotide coordination polymer as highly efficient peroxidase mimic for colorimetric detection of fluoride ion.

A new coordination polymer (Ce-Fe-GMP) with excellent catalytic activity was prepared by a facile route, which was further applied to the detection of F- with high sensitivity and selectivity. The simple doping of Fe3+ into the coordination network can easily modulate the mixing ratio of Ce3+ and Ce4+ in the presence of H2O2, which can extremely improve the catalytic ability of Ce-Fe-GMP. Based on the synergistic effect, the Ce-Fe-GMP with dual-active sites shows better peroxidase activity than that of Ce-GMP. In addition, we found that F- can inhibit the peroxidase activity of Ce-Fe-GMP because of the coordination structure fragmentation and the regulation of Ce3+/Ce4+ ratio. Therefore, different concentrations of F- can be detected by the colorimetric reaction based on this mechanism. The absorption at 652 nm displays a good linear relationship versus the concentration of F- over the range 2.0 to 100.0 μM. Furthermore, F- in real mineral-mixed samples can be measured with satisfactory results. The colorimetric strategy based on the peroxidase activity of Ce-Fe-GMP is simple and low-cost, which shows the potential applications in the field of on-site environment measurement.