Single-Molecule Catalysis and Imaging Techniques

Single-molecule catalysis employs advanced optical and spectroscopic methods to observe the behaviour and reactivity of individual catalytic sites or particles, thereby eliminating ensemble averaging and revealing intrinsic heterogeneity. Techniques such as fluorescence microscopy, chemiluminescence imaging, scattering-based detection and super-resolution microscopy have been combined with bespoke nanofluidic platforms and nanoconfined environments to track turnover events, reaction intermediates and energy barriers at the molecular scale. This approach has elucidated real-time kinetics, site-specific activation energies and structure–function correlations that are obscured in bulk measurements. Insights gained from single-molecule studies inform the rational design of catalysts with improved selectivity, activity and durability, with broad implications for energy conversion, environmental remediation and fine‐chemical synthesis. Integration of in situ and operando imaging under realistic reaction conditions is driving progress towards a molecular-level understanding of catalytic mechanisms and guiding scalable applications.

Research from Nature Portfolio

Recent studies have achieved direct optical tracking of single-molecule chemiluminescent reactions in homogeneous solution under catalytic conditions, uncovering Michaelis–Menten kinetics at both particle and active-site levels and enabling measurement of activation energies for individual catalyst entities. Investigations into nanoconfined core–shell catalysts have demonstrated how pore length and diameter modulate molecular orientation, adsorption strength and intermediate lifetimes, providing a molecular-scale rationale for enhanced activity. Additionally, a microfabricated nanofluidic reactor has been introduced to isolate tens of individual nanoparticles in parallel channels, permitting high-throughput fluorescence analysis of catalytic turnover across mass-transport and surface-reaction regimes.

Single-Molecule Catalysis and Imaging Techniques publication trend

The graph below shows the total number of articles in single-molecule catalysis and imaging techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Single-molecule catalysis: Study of the activity and kinetics of catalysts at the level of individual molecules or nanoparticles to avoid ensemble averaging and reveal intrinsic heterogeneity.

Chemiluminescence: Light emission resulting from a chemical reaction, used as a sensitive signal to monitor reaction events at the single-molecule level.

Nanofluidic device: Microfabricated platform containing fluidic channels with nanometre-scale dimensions, designed to isolate and control single molecules or particles during reaction monitoring.

Turnover frequency: Number of substrate molecules converted per active site or particle per unit time, a key metric of catalytic activity.

Nanoconfinement: Restriction of molecular movement within nanoscale pores or cavities, altering reaction pathways, adsorption strength and kinetics.

References

1. Mechanistic Insights Gained by High Spatial Resolution Reactivity Mapping of Homogeneous and Heterogeneous (Electro)Catalysts. Chemical Reviews (2023).
2. Direct probing of single-molecule chemiluminescent reaction dynamics under catalytic conditions in solution. Nature Communications (2023).
3. Deciphering nanoconfinement effects on molecular orientation and reaction intermediate by single molecule imaging. Nature Communications (2019).
4. A nanofluidic device for parallel single nanoparticle catalysis in solution. Nature Communications (2019).
5. Label-Free Imaging of Catalytic H2O2 Decomposition on Single Colloidal Pt Nanoparticles Using Nanofluidic Scattering Microscopy. ACS Nano (2023).