Study On The Catalytic Activity Of Gold Nanoparticles Based On Single Particle Collision Technology

Single particle collision electrochemical technology has been applied to study the electrochemical process of nanoparticles,such as liposomes,vesicles,viruses,and biological macromolecules.The electrochemical method based on the collision of nanoparticles can realize the rapid detection of the size,concentration and aggregation state of single nanoparticles,and then effectively distinguish the individual differences of nanoparticles and explore the relationship between the activity-structure of single particles,and it is for the detection of single entities.Basic features and dynamic charge transfer characteristics provide new methods.This paper successfully prepared a carbon deposition nanotube electrode that can be applied to single particle collision electrochemical technology.The size of the electrode can reach tens of nanometers,which can more sensitively detect the collision process of gold particles.This paper uses a carbon deposition nanotube electrode system to study the factors affecting the intrinsic catalytic activity of gold particles.The main contents of the paper are as follows:(1)Briefly introduce the basic knowledge of nanoparticles and ultramicroelectrodes,mainly from the classification and characterization of nanoparticles and ultramicroelectrodes.Emphasizes the introduction of the principle and recent development of single particle collision electrochemical technology,and gives a simple outlook on single particle collision technology.(2)The preparation of carbon-deposited nanotube electrodes and gold nanoparticles with different diameters is introduced.The quartz glass tube is drawn into glass nanotubes by a laser drawing instrument,and carbon is deposited on the glass nanotubes by thermal cracking of butane gas to prepare carbon deposition nanotube electrodes,and the ion current of the glass nanotubes is further tested.Its diameter is about 73.59 nm,and the effective area of carbon-deposited nanotube electrode measured by cyclic voltammetry is about 3.79ⅹ102 nm2.The redox reaction of chloroauric acid solution was used to prepare gold particles with a diameter of 13 nm,20 nm,and 40 nm with negatively charged surfaces and a diameter of 20 nm with positively charged gold particles.(3)The carbon-deposited nanotube electrode was used as the working electrode to detect the catalytic activity of gold particles as a peroxidase mimic(peroxidase-like).The single-particle collision technology detects the collision current response,quantifies the electron transfer characteristics of the reaction on the surface of the gold particle at the level of a single particle,and can characterize the intrinsic catalytic activity of the gold particle.Studies have shown that the size of the gold particles has a significant effect on its catalytic activity.The smaller the size of the gold particles,the greater the turnover number(TON)and the maximum turnover number(Kcat)of the gold particles,that is,the more reactions that occur on the surface of the nanoparticles,the more The better the effect;the positive charge on the surface of the gold particles is more conducive to its catalytic effect;the effect of the bias on the catalytic activity of the gold particles is positive feedback,and the applied bias can overcome the potential barrier of the redox reaction on the surface of Au NPs.The interaction between the carbon electrode and the gold particles can be exerted under the electric potential,resulting in faster reaction kinetics.(4)A carbon-deposited nanotube electrode was used as the working electrode to detect the catalytic activity of gold particles on sulfide/polysulfide redox reactions.Under different negative bias voltages,the amplitude of the current signal generated during collision will increase with the increase of the bias voltage.This is due to the reaction kinetics of S2-/Sn2-on the carbon electrode under a larger potential.Faster.In this paper,a highly sensitive carbon-deposited nanotube electrode is used as a working electrode to detect the electrochemical signal of gold particle collision,and the electron transfer characteristics of the redox reaction on the gold particle are obtained by statistical analysis of the electrical signal,and the factors that affect the intrinsic catalytic activity of the gold particle are deeply studied.To provide new ideas for the design of efficient nano-material catalysts.