Construction Of CAMP Stimuli?responsive Nanochannels And Its Research In Biomimetic Sensing

Ion channels are particularly prominent components of the nervous system.The transport of ions(Na⁺,K⁺,Ca²⁺,Cl^?)through ion channels is precisely modulated and controlled by a series of stimulus signals,such as a membrane potential change,a neurotransmitter,a mechanical deformation or binding with specific biomolecules.In response to these stimulus,ion channels display apparently a simple opening or closing of the pores.Inspired by ion channels,the development of biomimetic ion channels with high ionic transport efficiency and excellent controllability attracts great efforts in the past decade.These researches could not only help scientists better understand the ionic transport process in living systems,but also boost many exciting applications in smart nanofluidic devices,biosensors,molecular filtration,disease early diagnosis.Thus far,various smart nanochannels based on temperature,pH?,electrical field,or ionic potential stimulus responding modes have been developed,and display excellent gating performance comparable to that of ion channel proteins.However,artificial nanochannels modulated by biomolecules which make a crucial rule in natural biological systems are seldom reported in artificial systems,more intelligent artificial nanochannels manipulated by biomolecules especially signal?biomolecules are urgently needed.CAMP is one of the most important signal?biomolecules as the second messenger used for intracellular signal transduction.Importantly the cAMP binds to and directly regulates ion channels such as the cyclic nucleotide?gated ion channels（CNG channels）which are significant in sensory transduction as well as cellular development in the plasma membrane of some highly specialized cells.Through mimicking the highly specific binding model of cAMP and protein which exist in the CNG channel,we found that arginine could act an excellent receptor for cAMP utilizing multiple hydrogen bonding interactions.Thereby we further demonstrate a biomimetic cAMP?modulated nanochannel system consisting of cAMP recognized unit（ATGPA）capable of specifically binding with cAMP,and a flexible poly（N?isopropylacrylamide）（PNIPAAm）back?bone with a smart hydrogen bonding network to fulfill gating function in response to external stimuli through conformation change.The main research contents are as follows:...