Biofunctionalization of Water-Soluble poly(Phenylene Ethynylene)s

Area of Science:

• Polymer Chemistry
• Organic Chemistry
• Materials Science

Background:

• Water-soluble conjugated polymers, such as poly(phenylene ethynylene) (PPE), offer unique optical and electronic properties.
• Functionalization of these polymers is crucial for expanding their applications in various fields.
• Anionic water-soluble PPEs present a versatile platform for chemical modification.

Purpose of the Study:

• To develop a robust method for covalently linking diverse biofunctional groups to an anionic water-soluble PPE.
• To demonstrate the utility of the functionalized PPEs in prototype applications.
• To establish a versatile platform for creating new functionalized water-soluble conjugated polymers.

Main Methods:

• Amide coupling chemistry was employed to attach amine-functionalized groups to the PPE backbone via activated ester intermediates.
• Reaction conditions were optimized using biotin-ethylene diamine to control the degree of functionalization.
• Five distinct biofunctional moieties (biotin, rhodamine, cholesterol, mannose, folic acid) were successfully conjugated.

Main Results:

• A series of five novel biofunctionalized PPEs were synthesized with controlled loading of moieties.
• The rhodamine- and biotin-modified PPEs demonstrated successful application in pH sensing and flow cytometry labeling, respectively.
• The amide coupling strategy proved effective for diverse biofunctional group conjugation.

Conclusions:

• Amide coupling chemistry provides an efficient route for functionalizing anionic water-soluble PPEs.
• The developed method allows for the facile creation of tailored functional polymers for sensing, bioimaging, and flow cytometry.
• This approach is adaptable to other water-soluble conjugated polymer systems, broadening their application scope.