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Updated: Apr 21, 2026

Analyzing Large Protein Complexes by Structural Mass Spectrometry
Published on: June 19, 2010
Enhanced single molecule mass spectrometry via charged metallic clusters
Christopher E Angevine1, Amy E Chavis, Nuwan Kothalawala
1Department of Physics, Virginia Commonwealth University , Richmond, Virginia 23284, United States.
Adding a gold nanoparticle cluster to nanopores significantly enhances the detection of molecules like polyethylene glycol (PEG). This method improves the accuracy and range of nanopore sensing for various charged analytes.
Area of Science:
- Biophysics
- Nanotechnology
- Analytical Chemistry
Background:
- Nanopore sensing offers label-free characterization of water-soluble molecules.
- Accurate analyte identification in nanopores relies on molecule residence time.
Purpose of the Study:
- To investigate the effect of a gold nanoparticle cluster on analyte residence time in nanopores.
- To enhance the detection capabilities of nanopore sensing for molecules such as polyethylene glycol (PEG).
Main Methods:
- Immobilization of a Au25(SG)18 metallic cluster onto an α-hemolysin (αHL) nanopore.
- Measurement of polyethylene glycol (PEG) residence times within the modified nanopore.
- Analysis of current blockade distributions and development of a residence time model.
Main Results:
- The Au25(SG)18 cluster increased PEG mean residence time by over an order of magnitude.
- Enhanced residence time improved the range of detectable PEG sizes and peak resolution.
- Coulombic interactions between the charged analyte and cluster were identified as key to residence time enhancement.
Conclusions:
- Binding a metallic cluster to nanopores significantly enhances analyte residence time.
- This approach improves the sensitivity and resolution of nanopore-based molecular characterization.
- The cluster-based strategy shows potential for detecting a broader range of charged analytes.
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