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Updated: Nov 2, 2025
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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
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Detecting Individual Bond Switching within Amides in a Tunneling Junction
Mingzhu Huang1,2, Qinghai Zhou3, Feng Liang1
1The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, Wuhan University of Science and Technology, Wuhan, Hubei 430081, China.
Nano Letters
|June 14, 2021
Summary
Researchers monitored amide bond changes at the single-molecule level, observing transitions between single and double bonds. This breakthrough reveals critical insights into amide structure and reactivity using distinctive conductance features.
Area of Science:
- Chemical Physics
- Molecular Biophysics
- Nanotechnology
Background:
- Amides are fundamental to biological chemistry, influencing molecular structure and reactivity.
- Understanding amide bond states is crucial for elucidating their stability and planarity.
- Previous research lacked methods for single-molecule detection of amide bond changes.
Purpose of the Study:
- To develop a method for detecting and measuring bond state changes in amides at the single-molecule level.
- To investigate the dynamic transitions between single and double bonds in amides.
- To correlate conductance features with specific chemical bond states in molecular junctions.
Main Methods:
- Real-time monitoring of conductance in a nanogap between gold electrodes.
- Utilizing distinctive conductance features to identify bond state transitions.
- Employing density functional theory (DFT) simulations to model proton transfer mechanisms.
Main Results:
- Successfully monitored real-time transitions between single and double N-C bonds in amides.
- Identified distinct conductance signatures corresponding to different bond states.
- DFT simulations confirmed proton transfer via a water bridge as the switching mechanism.
- Observed bimodal conductance states in molecular junctions, differing by up to ninefold.
Conclusions:
- The study demonstrates the first real-time, single-molecule detection of amide bond state dynamics.
- Proton transfer facilitated by water molecules drives isomer switching in amides.
- Distinct conductance states provide a measurable signature of N-C bond transitions in molecular junctions.
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