Modulating Nanoparticle Translocation By Surface Chemistry Of Gold Nanopores

Nanopore analysis technology is a discipline with broad development prospects,which will open up new fields and ideas for scientific research.Quartz nanopore is a nanopore that is easy to manufacture and easy to operate.It can be used as a multi-functional nanoprobe for single cell analysis,which can realize rapid material transfer and has the advantages of small interface capacitance and low background noise.The operating principle of solid-state nanopore sensors is very simple.In a typical experiment,biomolecules are driven by externally applied voltages through the nanopore for electrophoresis or electroosmosis,resulting in changes in ion currents.From these mechanisms,molecular properties can be extracted.Information such as length,composition and interactions with other biomolecules.When small protein molecules pass through the nanopore detector,these small molecules have a high translocation rate and a low probability of passing through the nanopore,resulting in detection of only a small portion of the protein,which is a challenge for researchers.Therefore,this paper focuses on the simpler and more efficient nanopore detection tools,providing a strong theoretical basis for biology,medicine,and biophysics.In this paper,a single quartz capillary nanopore was selected as a sensing platform to study its potential applications in electrochemical detection and bioassay.The specific work is as follows:In the first chapter,a brief introduction to the basics of nanoelectrodes and nanopores.It is mainly explained in terms of types,preparation,application and detection principle.To understand the research background,research progress and potential value of nanosensors in detail,the design ideas and research contents of this paper are proposed.In the second chapter,we mainly introduce the preparation methods of two kinds of gold electrodes and two different insulation methods.The chemical deposition method deposits gold on the outer wall of the quartz nanotube,and the gold layer is not dense enough.In the second method,Apiezon wax insulation is very simple and efficient.Generally,bare quartz nanopores require specific modifications to impart certain chemical and electrochemical properties,further improving selectivity and sensitivity.In the third chapter,in order to enhance the ability of the nanoprobe to recognize the detection substance,the surface modification of the gold nanoelectrode is performed.The surface of the gold nanopore was modified with 4-aminothiophenol?4-ATP?,4-mercaptobenzoic acid?4-MBA?and 4-MBA and Cu²⁺,respectively.Finally,quartz nanopores,gold nanopores and surface-modified gold nanopores were used to detect the nanoparticles,and the ion current peaks were used to judge the translocation of the nanoparticles,and the properties of the nanopores were inferred.Comparing the experimental results,we can draw conclusions:?1?Voltage is the main factor affecting the movement of nanoparticles.The higher the voltage,the faster the movement rate of nanoparticles;?2?The surface charge of nanopores can adjust the translocation state of nanoparticles.By changing the charge on the surface of the nanopore,the width of the ion current peak and the shape of the peak change in the movement of the nanoparticle,so that the movement state of the nanoparticle can be regularly controlled by adjusting the surface charge.During the experiment,the metallization layer of the gold nano-electrode can be applied with an alternating voltage,and the nano-particles cause dielectrophoresis in the non-uniform electric field due to the polarization effect,so that more nanoparticles migrate to the nanopore more rapidly,further improving the detection efficiency.