The fabrication of quantum dots microgel based POCT microfluidic chip for simultaneously detecting multiple pathogenic heavy metal ions and its applications in actual water samples

Heavy metal ions pollution is one of the most threatened issues for human health and ecosystem balance. Herein, a promising microfluidic chip with microgel arrays for realizing the simultaneously point of care test to multiple pathogenic heavy metal ions was designed, which consisted of a sample perfusion area in the center (pipe width 200 μm), and four detection chambers (width 8000 μm, length 20000 μm) with microcolumn arrays (radius 100 μm, width 550 μm), all the heights were 100 μm. With simulation of the fluid flow, the flow rate of 5 mL/min made the microgel successfully patterning the precursor in microcolumn. By utilizing different kinds of quantum dots microgels, this chip could achieve specific and on-site quick detection for Pb 2+ , Co 2+ , Cu 2+ and Fe 3+ . Moreover, the gel composition had almost no effect on the performance of quantum dots and owned enough space after losing water to absorb the sample solution for reacting with the analytes. Furthermore, this POCT microfluidic chip was applied in the detection of actual water samples, and the fluorescence quenching of the chip was visible to naked eyes. It possessed the potential to achieve the ions quantitative determination. Therefore, this method realized the simultaneous detection of multiple pathogenic heavy meatal ions rapidly and availably and could further applied in actual water pollution samples with enormous advantages.