Magnetic mesoporous thiourea-formaldehyde resin as selective adsorbent: A simple and highly-sensitive electroanalysis...

A simple and sensitive electroanalysis method has been developed for the direct determination of lead ions of nanomolar levels in real samples of drinking water and milk by employing magnetic mesoporous thiourea-formaldehyde resin (TUF@Fe₃O₄) nanocomposites as the capturing absorbents. Here, the prepared TUF@Fe₃O₄ with the large-surface-area mesoporous structure and strong Pb²⁺-binding ligands could facilitate the selective and large-scale adsorption of Pb²⁺ ions from the complex sample matrices to be further magnetically separated onto the magnetic electrodes. Moreover, the Pb²⁺ ions magnetically accumulated were electrochemically measured alternatively by the solid state-based anodic stripping of PbCl₂. The detection limit was found to be 0.0070nmolL^-1. The as-developed Pb²⁺ electroanalysis method with the magnetic electrodes and TUF@Fe₃O₄ nanocomposites could avoid the complicated sample preparation and electrode modification, thus holding the great potential of applications for the Pb²⁺ detection in different real samples.