Dual functional membrane capable of both visual sensing and blocking of waterborne virus

Here, we introduce a dual functional membrane capable of both easy detecting with the naked eye and blocking noroviruses. We employed an anodized aluminum oxide (AAO) membrane with uniform pores. The top and bottom parts of the membrane were grafted with polydiacetylene (PDA) and poly(N-isopropylacrylamide) (PNIPAM), respectively. The top part was further bioconjugated by antibody for feline calicivirus (FCV), which is a model virus whose structure is similar to norovirus. The membrane showed color change from blue to red when the FCVs were attached to the antibodies. Water flux was controlled (turned on and off) by changing water temperature by using the well-known thermosensitive property of PNIPAM chains. On and off control of water flow was quickly established (less than 5 s) when a laser with near infrared (NIR) wavelength was turned on and off, respectively. In addition, the membrane completely blocked the virus influx into the water system by antibody binding before visual sensing followed by flow control.