Poly(ethylene glycol) diacrylate based hydrogel filled micropore with enhanced sensing capability

Area of Science:

• Materials Science
• Nanotechnology
• Biophysics

Background:

• Ionic current rectification (ICR) typically occurs in nanopores due to electrical double-layer overlap.
• Microscale ICR in larger pores is possible but less explored.
• Hydrogel-based systems offer tunable properties for ionic transport control.

Purpose of the Study:

• To demonstrate and investigate microscale ICR in a functionalized hydrogel-filled micropore.
• To explore the impact of hydrogel properties and environmental factors on micropore ICR.
• To develop a sensitive biosensing platform utilizing microscale ICR.

Main Methods:

• Fabrication of a conical micropore filled with a charged hydrogel (PEGDA-based).
• Systematic investigation of ICR phenomena by varying hydrogel space charge density, micropore geometry, filling length, electrolyte concentration, and pH.
• Development and testing of a biosensing platform using the hydrogel-filled micropore for detecting specific analytes.

Main Results:

• Successfully realized microscale ICR in the homogenous hydrogel-filled micropore.
• Identified key parameters influencing micropore ICR, including hydrogel properties and solution conditions.
• Achieved highly sensitive detection of model analytes (PML/RARA fusion genes, ATP) with a detection limit of 0.1 pM, enhanced by the weakly charged hydrogel.

Conclusions:

• Microscale ICR is achievable in hydrogel-filled micropores, offering a robust alternative to traditional nanopore systems.
• The developed hydrogel-filled micropore platform demonstrates significant potential for sensitive and facilitated biosensing applications.
• This work paves the way for more robust and easily fabricated ICR-based devices with wider applicability.