Portable paper-based molecularly imprinted sensor for visual real-time detection of influenza virus H5N1

The rapid detection of pathogens is important to the control of epidemics. Here, a paper-based molecularly imprinted sensor has been developed for the visual detection of influenza H5N1 virus. Firstly, the paper-based molecularly imprinted was prepared by a sol-gel reaction. Then, H5N1 similar to Apt was covalently bound to the surface of the ZIF-8-NH2 coated with rhodamine B (RhB) through an amide bond, to produce the fluorescent and colorimetric probe ZIF-8-NH2@RhB similar to Apt. When H5N1 and ZIF-8-NH2@RhB similar to Apt are added to the paperbased MIPs, the H5N1 will be combined with MIPs through the synergistic effects of shape and size compatibility and interaction with the functional groups of the monomers, and ZIF-8-NH2@RhB similar to Apt will bind to H5N1 through its aptamers to form a sandwich structure. The sensor has ultra-high sensitivity and the detection limit is 0.58 fmol/L by using fluorescence spectroscopy. A semi-quantitative signal can also be observed with the naked eye within 10 min. A comparative study showed that direct visual detection was highly reliable, and the sensitivity was better than that achieved with a commercially available kit. Importantly, the paper-based sensor is low in produce cost (Original size: RMB 1.53 Yuan each; Smaller size: RMB 0.08 Yuan each) and is easy to cut, store and carry. This sensor is expected to allow self-service, visual, high-throughput, and real-time virus detection, which is of great significance for epidemic prevention and control.