Electrophoretic chip based on special wettability surfaces for detection of heavy metals

Electrophoretic chip coupling to electrochemical detection enables the separation, monitoring, and on-site testing of multiple analytes simultaneously. However, bonding technology and detection sensitivity of the electrophoretic chip have severely diminished its value in industrial production. In this paper, a novel open PDMS/PCB electrophoretic chip based on special wettability surfaces was proposed. The developed chip employs the combination of superhydrophobic surface and super-hydrophilic microchannels to complete the function of bonding technology, avoiding the unreliability of the bonding process. The developed chip applied the super-hydrophilic porous MXene/CeO₂/PVA hydrogels electrode, enhancing the sensitivity of chip. Finally, the developed chip was employed to simultaneously detect Pb²⁺, Hg²⁺, Cu²⁺, and Cd²⁺ in laboratory and tap water via differential pulse voltammetry (DPV). It exhibited excellent performance with a low limit of detection (Pb²⁺ 0.96 nM, Hg²⁺ 0.87 nM, Cu²⁺ 0.80 nM, and Cd²⁺ 0.97 nM). The features of cost-effectiveness, high-reliability, and high-sensitivity make this electrophoretic chip useful for on-site monitoring of multiple analytes in industrial and medical fields.