Three-dimensional paper-based microfluidic chip device for multiplexed fluorescence detection of Cu2+ and Hg2+ ions based on ion imprinting technology

•The paper based microfluidic platform provided a simple, robust and user-friendly way for multiplexed detection Cu2+ and Hg2+ ions.•This method can realize the liquid phase of QDs@IIPs being transferred to the solid glass fiber paper and improve the portability of the device.•The real samples were successfully analyzed with good sensitivity, selectivity and reliability.