Selective Detection and Characterization of Small Cysteine-Containing Peptides with Cluster-Modified Nanopore...

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Resistive-pulse nanopore sensing monitors ligand-induced fluctuations in gold nanoclusters.
• Previous work showed fluctuation magnitude correlates with ligand size and ligand exchange can be observed.

Purpose of the Study:

• To explore current fluctuations from peptide ligands attaching to thiopronin-capped gold nanoclusters.
• To determine if these fluctuations can identify specific peptides.
• To assess the potential for selective peptide detection.

Main Methods:

• Utilized resistive-pulse nanopore sensing to analyze gold nanoclusters.
• Investigated current fluctuations upon peptide ligand attachment.
• Examined the role of cysteine residues in peptide attachment.

Main Results:

• Peptide attachment to gold nanoclusters generates distinct current fluctuations.
• Fluctuation magnitude and high-frequency changes can identify specific peptides.
• Peptide attachment requires a cysteine residue, enabling selective detection.
• Multiple cysteine-containing peptides were identified in mixtures.

Conclusions:

• Nanopore sensing of gold nanocluster fluctuations offers a method for peptide identification.
• The requirement of cysteine allows for selective detection of specific peptides.
• This technique can be applied to identify multiple peptides within complex mixtures.