CAMP-modulated biomimetic ionic nanochannels based on smart polymer

Zhixiang Chen,^ab Taolei Sun^a and Guangyan Qing*^b

J. Mater. Chem. B, 2019, 7, 3710.

DOI: 10.1039/c9tb00639g

  The flow of ions across the cell membrane is essential to many life processes. Cyclic 3’, 5’-adenosine monophosphate (cAMP) binds to and regulates the function of cyclic nucleotide–gating channel proteins, which directly mediate the Na⁺/Ca²⁺ transmembrane behaviours. This inspires us to develop a biomimetic cAMP–modulated ionic nanochannel based on a cAMP–responsive polymer design. Driven by specific hydrogen bonding interactions with cAMP, arginine–based smart copolymer film displays remarkable adsorption toward cAMP and can clearly discriminate cAMP from other nucleotides, accompanied with reversible conformational transition of the polymer chain from a contracted state to a swollen one. Benefiting from these features, dynamic gating behaviours of the nanochannels located on the copolymer–modified anodic aluminum oxide (AAO) membrane could be precisely manipulated by cAMP. Sensitive responsiveness (10 pmol·L^–1) and high specificity toward cAMP, high controllability and satisfactory reversibility reveal the great potential of biomolecule responsive polymers in biomimetic nanochannels and nanodevices.