Related Experiment Video
Updated: Feb 20, 2026
10:02
Submillisecond Conformational Changes in Proteins Resolved by Photothermal Beam Deflection
Published on: February 18, 2014
9.5K
A solution-based single-molecule study of surface-bound PBIs: solvent-mediated environmental effects on molecular
Ji-Eun Lee1, Ye Ri Han, Sujin Ham
1Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea. dongho@yonsei.ac.kr.
Physical Chemistry Chemical Physics : PCCP
|October 26, 2017
Summary
Single perylene bisimide (PBI) molecules were studied in solution using single-molecule imaging. PBI molecules exhibit environment-dependent dynamics, with restricted motion observed in aqueous solutions due to hydrogen bonding.
Area of Science:
- Photophysics
- Supramolecular Chemistry
- Materials Science
Background:
- Perylene bisimide (PBI) molecules are widely used in organic electronics and as fluorescent probes.
- Understanding their photophysical properties at the single-molecule level is crucial for designing advanced molecular devices.
- Environmental factors significantly influence the behavior of organic molecules in solution.
Purpose of the Study:
- To investigate the fundamental photophysical properties of single surface-bound perylene bisimide (PBI) molecules in solution.
- To explore the influence of local and chemical environments on PBI fluorescence dynamics.
- To visualize and understand the spatial fluctuations and molecular motion of PBIs in different solvents.
Main Methods:
- Single-molecule immobilization on glass substrates.
- Confocal microscopy for simultaneous monitoring of fluorescence intensity, lifetime, and emission spectra.
- Defocused wide-field imaging for visualizing spatial fluctuations.
- Investigation in both organic and aqueous media.
Main Results:
- Single PBI fluorescence dynamics are highly sensitive to the surrounding environment.
- PBIs exhibit greater steric flexibility in organic solvents compared to aqueous solutions.
- A previously unobserved cage effect, attributed to hydrogen bonding, restricts PBI motion in water.
- Distinct spatial fluctuations were visualized for surface-bound PBIs.
Conclusions:
- The study reveals environment-dependent photophysical behavior of single PBIs.
- Hydrogen bonding in aqueous solutions significantly hinders PBI molecular motion.
- The developed single-molecule technique offers new avenues for studying complex molecular systems.
- This research contributes to the development of optimized molecular devices, including waterproof applications.
