Polyelectrolyte Multilayer Films at Liquid-Liquid Interfaces
Inventors: Nicholas Abbott, Nathan Lockwood, Katie Cadwell, Frank Caruso, Elvira Tjipto
The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a method for providing a PEM film at the interface between a liquid crystal and an aqueous solution.
Polyelectrolyte multilayers (PEMs) are successive layers of alternating anionic and cationic polymeric coatings that can be modified to incorporate a variety of adducts. Excipients, including polyelectrolytes, can also be added to functionalize the PEM layers. PEMs are useful as systems for drug and gene delivery, chemical sensors and coatings for silicon wafers, among other things.
UW-Madison researchers have developed a method for providing a PEM film at a liquid-liquid interface, such as the interface between a liquid crystal (LC) and an aqueous solution. A PEM can be incorporated between an LC and an aqueous solution by sequentially depositing layers of anionic and cationic polyelectrolytes at the interface. This modifies the interface and effectively functionalizes the LC layer. If the appropriate adducts and excipients are in the PEM, the PEM can transduce signals from the aqueous solution to the LC. For example, receptors incorporated in the PEM can recognize and bind ligands in the aqueous solution, resulting in changes that alter the orientation of the LC. This alteration can then be easily observed to determine if the ligand is present in the solution.
- Allows current LC-based technologies to detect a broader spectrum of molecules in aqueous, and possibly atmospheric, environments
- Because PEMs can be separated from the LCs and the aqueous solutions, this provides a general route to the formation of free-standing PEMs, which have many uses, including as mobile sensors or as “smart dust.”
- Enhances the properties of LCs
- PEMs can accommodate an almost endless variety of adducts and excipients, enabling them to detect a vast array of molecules.
- PEMs can stabilize liquid-liquid interfaces and prevent molecules from adsorbing to them.
- Systems containing multiple enzymes could be hosted within PEMs formed at liquid-liquid interfaces to increase the amount of enzyme available at the interface, as well as to maximize the activity and stability of the enzymes.