An ion imprinting technology-assisted rotational microfluidic hybrid chip for the fluorescence detection of hexavalent chromium ions.

Ion imprinting technology was integrated on a rotational microfluidic paper- and cloth-based hybrid chip for the sensitive and selective detection of hexavalent chromium (Cr(VI)) ions. The rotational microfluidic hybrid chip consisted of CdTe quantum dot based ion imprinting fluorescence sensing cloth and three layers of paper. Users can collect fluorescence signals conveniently rotating the paper layer to expose the corresponding cloth-based sensing component. One microfluidic hybrid chip can realize the four-set multiplexed detection of Cr(VI) ions, with each set providing three parallel measurements. Furthermore, the quantitative determination of Cr(VI) ions can be achieved substituting the calculated fluorescence quenching value into the linear calibration curve. The ion imprinting fluorescence sensing microfluidic hybrid chip provides a simple, efficient, and user-friendly device for Cr(VI) ion detection. Moreover, it might be further adapted for other sensing systems and the point-of-care testing of pollutants in combination with portable instruments or smartphones.