The strategy of antibody-free biomarker analysis by in-situ synthesized molecularly imprinted polymers on movable valve paper-based device.

In this work, we provided a novel strategy of antibody-free biomarker analysis by in-situ synthesized molecularly imprinted polymers (MIPs) on movable valve microfluidic paper-based electrochemical device (Bio-MIP-ePADs) for clinical detection of biomarkers. The newly movable valves on the device enable continuous and convenient delivery of fluid, which guarantee the performance for fabricating MIPs structure during long time electropolymerization. Moreover, this strategy can directly detect antigens by taking advantage of molecular imprinting on paper-based device, which greatly decreases the cost during clinical testing, reduces the tedious washing procedure and does not need to consider the preservation of the antibody in enzyme linked immunosorbent assay (ELISA). This feature makes the chip suitable for the on-site family treatment or commercial products. To further validate the applicability of this proposed method for clinical diagnostic testing, carcinoembryonic antigen (CEA) was applied as prototyping model target for the clinical analysis. The proposed Bio-MIP-ePADs were cheap, easy to prepare, disposable and provided reliable analysis by comparing with ELISA. We hope the application of this technology will open up a new avenue to the point-of-care testing (POCT).