Regulating the molecule and electrode interface of a single-molecule junction via the side chain
Yunpeng Li1, Ajun Tang1, Rui Wang1
1Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China. lihongxiang@ecust.edu.cn.
Chemical Communications (Cambridge, England)
|March 29, 2023
Summary
A novel single-molecule junction probe, PyCHO, can differentiate cysteine and homocysteine. This is achieved by regulating the molecule-electrode interface, leading to distinct conductance signals for the reaction products.
Area of Science:
- Molecular electronics
- Chemical sensing
- Biomarker detection
Background:
- The molecule-electrode interface is crucial for single-molecule junction properties.
- Distinguishing between structurally similar biomolecules like cysteine and homocysteine remains a challenge.
- Developing selective and sensitive molecular probes is essential for early disease detection.
Purpose of the Study:
- To develop a single-molecule junction probe capable of selectively detecting cysteine and homocysteine.
- To investigate the role of side chains in regulating molecule-electrode interfaces.
- To understand the mechanism behind the selective detection of cysteine and homocysteine.
Main Methods:
- Fabrication of single-molecule junctions.
- Development of a PyCHO probe that reacts with cysteine/homocysteine.
- Single molecular conductance measurements.
- Control experiments and theoretical calculations.
Main Results:
- The PyCHO probe successfully distinguished between cysteine and homocysteine.
- The probe formed distinct thiazolidine and thiazinane products upon reaction.
- Single molecular conductance measurements revealed different conductances for PyCHO+Cys and PyCHO+Hcy.
- Theoretical analysis confirmed that side rings distinctly affect the Au-π interaction, causing conductance differences.
Conclusions:
- Side chain engineering of molecular junctions offers a powerful strategy for regulating interfacial properties.
- The PyCHO probe demonstrates high selectivity and sensitivity for differentiating cysteine and homocysteine.
- This work provides a new platform for developing advanced molecular electronic sensors for biomedical applications.
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