Fabrication of a Smart Nanofluidic Biosensor through a Reversible Covalent Bond Strategy for High-Efficiency Bisulfite Sensing and Removal.

Bioinspired nanochannel based biosensors have been widely applied for sensing ions, small molecules, and biomolecules. However, the low selectivity and difficulty in recycle sensing still heavily hamper their widespread applications. Herein, we designed and fabricated a nanochannel based biosensor for high-efficiency bisulfite (HSO3-) sensing and removal through forming a reversible covalent bond between HSO3- and 4-aminophenyl-phenyl-methanone (APPM). This nanofluidic biosensor displays a promising HSO3- selectivity with high ion rectification/gating ratio (47 and 5) and excellent reversibility and stability. Of note, the L02 cell line containing excess HSO3- could still maintain high vitality in the presence of such an APPM-functionalized biosensor based membrane. These results will not only help to better understand the biological function of HSO3- in living organisms but also inspire us to develop smart artificial nanochannel based biosensors for biological applications.