Existential state of solutes substantially affects the efficiency and direction of vari-ous chemical and biological processes,about which current consensus is still limited at macro and micro levels.At the trace level,...Existential state of solutes substantially affects the efficiency and direction of vari-ous chemical and biological processes,about which current consensus is still limited at macro and micro levels.At the trace level,solutes assume a pivotal role across a spectrum of criticalfields.However,their existential states,especially at inter-faces,remain largely elusive.Herein,an exceptional evolution of solute molecules is unveiled from micro to trace,solution to interface,with the aid of surface-enhanced Raman spectroscopy,extinction,DLS and theoretical simulations.Given predom-inant existence of monomers within the solution,these aggregates dominate the interfacial behavior of solute molecules.Moreover,a universal,aggregate-controlled mechanism is demonstrated that aggregates triggered by cosolvent,which can dra-matically promote efficiency of catalytic reactions.The results provide novel insights into the interaction mechanisms between reactants and catalysts,potentially offering fresh perspectives for the manipulation of multiphase catalysis and related biological processes.展开更多
Owing to their structural dispersion,the catalytic properties of nanoparticles are challenging to characterize in ensemble-averaged measurements.The single-molecule approach enables studying the catalysis of nanoparti...Owing to their structural dispersion,the catalytic properties of nanoparticles are challenging to characterize in ensemble-averaged measurements.The single-molecule approach enables studying the catalysis of nanoparticles at the single-particle level with real-time single-turnover resolution.This article reviews our single-molecule fluorescence studies of single Au-nanoparticle catalysis,focusing on the theoretical formulations for extracting quantitative reaction kinetics from the single-turnover resolution catalysis trajectories.We discuss the single-molecule kinetic formulism of the Langmuir-Hinshelwood mechanism for heterogeneous catalysis,as well as of the two-pathway model for product dissociation reactions.This formulism enables the quantitative evaluation of the heterogeneous reactivity and the differential selectivity of individual nanoparticles that are usually hidden in ensemble measurements.Extension of this formulism to single-molecule catalytic kinetics of oligomeric enzymes is also discussed.展开更多
文摘Existential state of solutes substantially affects the efficiency and direction of vari-ous chemical and biological processes,about which current consensus is still limited at macro and micro levels.At the trace level,solutes assume a pivotal role across a spectrum of criticalfields.However,their existential states,especially at inter-faces,remain largely elusive.Herein,an exceptional evolution of solute molecules is unveiled from micro to trace,solution to interface,with the aid of surface-enhanced Raman spectroscopy,extinction,DLS and theoretical simulations.Given predom-inant existence of monomers within the solution,these aggregates dominate the interfacial behavior of solute molecules.Moreover,a universal,aggregate-controlled mechanism is demonstrated that aggregates triggered by cosolvent,which can dra-matically promote efficiency of catalytic reactions.The results provide novel insights into the interaction mechanisms between reactants and catalysts,potentially offering fresh perspectives for the manipulation of multiphase catalysis and related biological processes.
基金We thank the Army Research Office(56355-CH)National Science Foundation(NSF,No.CBET 0851257)+1 种基金American Chemical Society Petroleum Research Foundation(No.47918-G5)NSF-funded Cornell Center for Materials Research for fi nancial support。
文摘Owing to their structural dispersion,the catalytic properties of nanoparticles are challenging to characterize in ensemble-averaged measurements.The single-molecule approach enables studying the catalysis of nanoparticles at the single-particle level with real-time single-turnover resolution.This article reviews our single-molecule fluorescence studies of single Au-nanoparticle catalysis,focusing on the theoretical formulations for extracting quantitative reaction kinetics from the single-turnover resolution catalysis trajectories.We discuss the single-molecule kinetic formulism of the Langmuir-Hinshelwood mechanism for heterogeneous catalysis,as well as of the two-pathway model for product dissociation reactions.This formulism enables the quantitative evaluation of the heterogeneous reactivity and the differential selectivity of individual nanoparticles that are usually hidden in ensemble measurements.Extension of this formulism to single-molecule catalytic kinetics of oligomeric enzymes is also discussed.
