Constructed A Single-Molecule Super-Resolution Fluorescence Imaging System For In-Situ Dynamic Analysis Of A Single Particle Surface Reaction Process

Interface reactions are widely prevalent in the field of chemical catalysis.Investigating the mechanisms of interfaces reactions and optimizing their reaction processes are crucial for enhancing the catalytic activity of particles.However,due to the heterogeneity of particles in terms of type,composition,shape,and structure,the pathways of interface reactions are complex,leading to significant heterogeneity in reaction activity.The average results obtained by traditional macro analysis techniques concealed the heterogeneity of intergranular reactivity and severely limited the identification of surface interface reaction pathways.This presents a substantial challenge for precise analysis of interface reactions at the particle surface.Real-time in-situ detection of interface reactions at the single-molecule level is an effective approach to address these issues.By correlating of the dynamically analyzing the reactions at the surface interfaces in real time,and the catalyst size,crystal facets,defects,composition,and various external field factors,the regulated mechanisms of particle structure and external factors could be accurately understanded.This has significant scientific importance for guiding the design and synthesis of highly active catalyst particles.However,the application of single-molecule level analysis techniques is challenging for real-time dynamic monitoring of interface reactions at particle surface.It is due to the absence of particle manipulation technologies,the difficulty in loading in-situ reaction conditions,and the challenges in precise detection of surface interface reactions.Therefore,there is an urgent need to develop a single-molecule level imaging system suitable for the process of interface reactions at particle surface.This system will be a powerful tool for accurately understanding the process of interface reactions,revealing the regulatory mechanisms of catalyst structure and various external factors on these reactions,and guiding the design and synthesis of highly active catalysts.To address the challenges in interfacial studies,this paper undertakes the following tasks:1.Establishment of a single-molecule super-resolution fluorescence imaging system.The system achieves a detection sensitivity at the single-molecule level,a spatial resolution of 30 nm,and the temporal resolution of 1 ms.Besides possessing high sensitivity and resolution,the single-molecule super-resolution fluorescence imaging system facilitates effective manipulation of individual particles through coupled microfluidic reaction chips,enabling in-situ real-time observation of individual particle surface interfacial reactions.Furthermore,by controlling in-situ reaction conditions,the system provides external field environments such as light fields,electric fields,and magnetic fields,supporting the analysis of the regulatory mechanisms of interfacial reactions in the presence of external fields.Additionally,the obtained single-molecule fluorescence imaging of interfacial reactions is subjected to analysis using single-molecule localization algorithms,allowing precise spatial information on the distribution of active sites on particle surfaces and dynamic information on various interfacial reaction processes.This will provide theoretical guidance for accurately understanding the interfacial reaction process,recognizing the regulatory mechanisms of intrinsic and external factors,and guiding the design and synthesis of catalytic particles with high efficiency.2.Revelation of the regulatory effects and mechanisms of external electric fields on particle surface interfacial photocatalytic reactions.Using a self-built single-molecule localization super-resolution fluorescence imaging system,the spatial separation of photocatalytic oxidation-reduction reactions on individual BiVO₄ crystal surfaces under an electric field is visualized.By statistically analyzing the occurrence frequency of oxidation-reduction reactions on specific crystal facets,the dynamic redistribution behavior of oxidation-reduction reactions induced by the external electric field is revealed.Additionally,the single-molecule dynamics of photocatalytic oxidation-reduction reactions under an electric field are elucidated through fluorescence burst time trajectories.Through the analysis of single-molecule dynamics,we demonstrate that the adsorption step is the reaction rate-limiting step and is unaffected by the external electric field.The dynamic redistribution behavior of photocatalytic oxidation-reduction reactions is attributed to the regulation of catalytic conversion and desorption processes by the external electric field.The impact of an external electric field on photocatalysis is further validated through the hydrogen evolution reaction（HER）.Our research deepens the understanding of the mechanisms of electric field regulation on photocatalytic reactions,providing new design principles and visualization research methods for constructing efficient photocatalytic systems.3.Revelation of the regulatory mechanisms of magnetic field vector characteristics on the efficiency of photocatalytic oxygen evolution reactions.Based on the established single-molecule super-resolution fluorescence imaging system,the temporal and spatial regulation mechanisms of magnetic fields on the photocatalytic oxygen evolution reaction on ZnO nanorod interfaces are revealed.By monitoring the photocatalytic oxygen evolution reaction on ZnO nanorod interfaces in situ,the spatial distribution of active sites for oxygen evolution is obtained,identifying the generation of new active sites and spatial separation induced by the magnetic field effect.Combining density functional theory（DFT）calculations,the microscopic mechanism of the magnetic field-induced polarization effect of bridging oxygen atoms’outer electron clouds leading to the generation of new active sites is revealed.Further enhancement of the magnetic field vector effect and magnetic polarization effect is achieved by synthesizing ZnO nanorod arrays with Fe atom doping,significantly improving the activity of ZnO nanorod oxygen evolution reactions.4.Construction of an Au-Se electrode-biological interface（Au-Se interface）based on the Au-Se bond.Compared to the traditional Au-S bond-based Au-S interface,the Au-Se interface exhibits strong stability and lower charge injection barriers.The Au-Se electrodechemical detection platform effectively avoids false-positive effects caused by biological thiols,achieving high-fidelity detection of MMP-2.The strong stability of the Au-Se interface provides an effective strategy for the high-fidelity detection of intracellular protease at the molecular level.