Peptide Nanocarriers for Detection of Heavy Metal Ions Using Resistive Pulse Sensing

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomolecular Engineering

Background:

• Resistive pulse sensing (RPS) commonly uses polyionic carriers or nanomaterials for analyte detection.
• Existing methods often rely on DNA aptamers, whose polyanionic nature influences carrier velocity.
• A need exists for alternative nanocarriers with distinct charge properties for enhanced sensing.

Purpose of the Study:

• To develop and evaluate peptide-functionalized superparamagnetic nanocarriers for metal ion detection in solution.
• To investigate the influence of peptide charge on signal generation in RPS.
• To demonstrate the quantification of nickel ions (Ni2+) in environmental water samples.

Main Methods:

• Functionalization of superparamagnetic nanocarriers with peptide ligands.
• Utilizing RPS to measure changes in nanocarrier translocation velocity upon metal ion binding.
• Engineering charged groups within peptides to modulate signal response.
• Testing the assay's performance across a range of nickel ion concentrations and in the presence of interfering ions.

Main Results:

• Peptide-nanocarrier interaction with nickel ions caused measurable changes in translocation velocity.
• The magnitude of velocity change correlated with nickel ion concentration over three orders of magnitude.
• Engineered charged groups did not significantly alter the dominance of metal ion binding on velocity.
• Successful quantification of Ni2+ in tap water and pond water samples was achieved.

Conclusions:

• Peptide-functionalized superparamagnetic nanocarriers offer a viable alternative for metal ion sensing in RPS.
• The assay demonstrates high sensitivity and selectivity for nickel ions, even in complex matrices.
• This approach supports the development of future multiplexed sensing platforms combining peptides and DNA aptamers.