Thermocapillary convection modulating ion migration for rapid recognition and detection of Cu (Ⅱ) based on MnO2 NSs-AuNSs modified screen printed electrode

Microfluidic chip for sensing heavy metal ions has been strongly attended due to its merits, but still remains a large challenge from long analysis time derived from the preconcentration process of metal ions. Herein, a heated flow channel was manufactured by 3D printing combined with a filter paper to construct a microfluidic chip, the thermocapillary convection strategy was introduced to accelerate ions migration, allowing for rapidly recognizing metal ions. The MnO 2 nanosheets-Au nanostars (MnO 2 NSs-AuNSs) film was employed as modifier to fabricate a flexible screen printed electrode (SPE) for high-efficiency detecting metal ions based on thermocapillary convection accelerating accumulation method. To verify the proposed strategy, the detection of Cu 2+ was chosen as a model. The results revealed that the proposed strategy possessed a rapid detection to Cu 2+ , which greatly improved the detection efficiency (saved 400 s of preconcentration time) and achieved a detection limit down to 0.0270 ppb. Interestingly, the constructed method was successfully used to evaluate Cu 2+ concentration in sweat samples with satisfactory results. This proposed method maybe provide new insight to develop a novel approach to rapidly and sensitively detect metal ions, which possess huge utilization potentiality for safeguarding human health.