Fabrication Of Functional Nanochannels And Its Application As Biosensors

Cell membranes separate the interior intracellular space from the outside extracellular environment.Due to the structural incompatibility of the hydrophilic metabolites and the hydrophobic cell membranes,ions or molecules cannot diffuse through the cell membrane and their translocation may be facilitated by ion channels.Ion channels are pore‐forming proteins,regulating the flow of ions from either side of the cell membrane to the other,in response to external stimuli like p H,ionic strength,water content,etc.Artificial nanopores/nanochannels,the biomimetic products of biological ion channels,are promising materials in real world applications due to their robust mechanical and controllable chemical properties.Functional modifications of artificial nanopores/nanochannels pave a wide way for the introduction of varied properties,making them smart in response to external stimuli and regulating the transport of ions/molecules.Based on the above mentioned research background,some intelligent nanochannels with certain structure and function are fabricated.Furthermore,their applications in sensing are explored.The research content of the dissertation mainly includes the following two aspects:1.A new rapid and sensitive device for zinc finger peptide detection is fabricated with the ZIF-8-modified micropipets as sensing platform.First,an electrochemistry sensing platform based on ZIF-8-modified micropipets is designed.Second,the Zn（II）ion of ZIF-8 can specifically bind to residues of ZFP is proved,which provides the theoretical basis for the detection.Finally,the ZIF-8-modified micropipets to detect ZFP with a series of concentration gradients and the limit of detection can reach10^-2μg ml^-1.It will be important to further improve the detectability of peptides/proteins and,more importantly,to maximize efforts to create more ambitious functional molecules immobilized into the inner micropipets.A number of exciting developments in the near future are expected to be anticipated from the design,preparation process and experimental results as above reported.2.A highly sensitive and selective sensing device that detects DNA is developed.The target-DNA is integrated into the micropipets using specifically designed sensing probes.The formation of complex DNA nanostructures inside the micropipets efficiently blocks ion conduction.Thus,the presence of target-DNA could be identified by monitoring the change of the ionic current of the micropipets.The detection limit is 10 fmol/L for target-DNA.The non-specific DNA strands and interfering substances are effectively precluded by the sequence specific DNA nanostructures.The proposed strategy could be expanded to detect some diseases related molecular targets and play a considerable role in biosensing.