Electrochemical Investigation Of Biomolecules Based On Solid Nanochannel Array

Due to high mechanical strength,the controllable size and stability of the structure,solid nanochannels have recently attracted widespread attentions in gene sequencing,logic gate,molecular devices,biosensors and functional switches.Different from conventional flat electrode surface,solid nanochannel surface not only provides a surface to immobilize molecule,but also construct a different nanoscale environment from that of bulk solution.These special characterizations of nanochannels establish new platform for electrochemical analysis of biomolecules,particularly for electrochemical inactive macromolecules.In our investigations,through designing and constructing functionalized nanochannels with different size,we developed two new methods for electrochemical analysis of the electrochemical inactive biological molecules.The main contents were summarized as follows:1.The vertically ordered silica nanochannels array with diameter of?3 nm were synthesized.The pore size matched the cross-sectional diameter of i-motif structure,1.9 nm,which could promote the folding of i-motif DNA in neural pH solution environment.Such promotion for i-motif formation was not obtained in diluted solution and conventional flat electrode surface.A mechanism of enlarged proton environment trigged by nano-confinement of nanochannels was proposed to elucidate the promotion of i-motif formation in nanochannels.This approach undoubtedly paved a more diversified way for DNA engineer and DNA-based nanosensor.2.Employing asymmetric porous anodic alumina membrane,a new electrochemical method for tyrosinase detection was developed.The tyrosinase can specifically oxidize phenol hydroxyl to diphenol,resulting in rectifying current due to altered charge density.The results indicated that this tyramine-functional nanochannels array(AAO/Tyr)had good selectivity for tyrosinase,showing a good linear relationship ranging from 2 U/ml to 50 U/ml.Using this AAO/Tyr,we successfully detected tyrosinase in melanoma cells.This approach paved a new way for electrochemical analysis of electroinactive enzymes,and others molecules in biological systems.