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Bioinspired Dual-Responsive Nanofluidic Diodes by Poly-l-lysine Modification
Jun Li1, Pengrong An1, Chuanguang Qin1
1MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions, Joint Lab of Nanofluidics and Interfaces (LONI), School of Natural and Applied Sciences, Northwestern Polytechnical University, No. 127, Youyi Road (West), Xi'an City, Shaanxi Province 710072, P. R. China.
Researchers developed a smart nanofluidic device using poly-l-lysine (PLL) coating. This bioinspired modification allows dual control of ionic transport via pH and temperature, enabling reversible "ON" and "OFF" states for potential drug delivery applications.
Area of Science:
- Nanofluidics
- Biomaterials Science
- Surface Chemistry
Background:
- Stimuli-responsive materials are crucial for controlling physicochemical properties and transport phenomena in nanofluidic devices.
- Polyethylene terephthalate (PET) nanopores are widely studied, but surface modification is key to achieving advanced functionalities.
- Poly-l-lysine (PLL) is a biocompatible polymer frequently used in biotechnology for surface coatings.
Purpose of the Study:
- To engineer a dual-responsive nanofluidic channel by modifying a PET nanopore surface with poly-l-lysine (PLL).
- To investigate the effect of PLL coating on ionic transport rectification and its response to pH and temperature stimuli.
- To demonstrate the reversibility of ionic transport switching for potential applications in controlled delivery systems.
Main Methods:
- Bioinspired surface modification of conical ion track-etched PET nanopores using a poly-l-lysine (PLL) coating.
- Characterization of surface charge changes due to the carboxyl to amine group transition upon PLL assembly.
- Ionic transport measurements under varying pH and temperature conditions to assess conductivity switching and reversibility.
Main Results:
- The PLL-modified nanopore exhibited tunable ionic transport, achieving a nonconductive "OFF" state at pH 11.5 and 70 °C.
- Ionic transport could be switched to a conductive "ON" state by decreasing either pH or temperature.
- The transitions between "ON" and "OFF" states demonstrated excellent reversibility and stability.
Conclusions:
- The PLL-modified nanopore functions as a promising smart nanofluidic device with dual pH and temperature responsiveness.
- The demonstrated biocompatibility and ease of PLL modification highlight its potential for biomimetic ion/mass transport and drug delivery applications.
- This work advances the development of intelligent nanofluidic systems for sophisticated molecular manipulation and controlled release.
