A universal strategy for aptamer-based nanopore sensing through host-guest interactions inside α-hemolysin

Area of Science:

• Biophysical techniques
• Single-molecule analysis
• Nanopore sensing technology

Background:

• Nanopore sensing is a powerful single-molecule technique with applications in biophysics and stochastic sensing.
• Existing methods require further optimization for enhanced sensitivity and broad applicability.

Purpose of the Study:

• To develop a versatile nanopore sensing strategy.
• To improve detection limits for various analytes.
• To combine aptamer recognition with host-guest interactions for enhanced sensing.

Main Methods:

• Aptamer hybridization with a DNA probe modified with a ferrocene⊂cucurbit[7]uril complex.
• Analyte-induced unwinding of the aptamer-probe duplex, releasing the DNA probe.
• Translocation of the released DNA probe through an α-hemolysin nanopore to generate current events.
• Integration of magnetic beads to further reduce detection limits.

Main Results:

• The strategy enables quantitative detection of analytes via signature current events.
• Magnetic bead integration lowered detection limits by two to three orders of magnitude.
• Demonstrated a versatile approach applicable to a wide range of target molecules.

Conclusions:

• The proposed aptamer and host-guest interaction-based nanopore sensing strategy is highly versatile.
• This method offers a significant improvement in detection sensitivity for various analytes.
• The universal applicability makes it a valuable tool for nanopore-based molecular detection.