title: Design of functionalized cellulosic honeycomb films: site-specific biomolecule modification via "click chemistry".
abstract: Value-added materials from naturally abundant polymers such as cellulose are of significant importance. In particular, cellulosic open-framework structures with controlled chemical functionality of the internal surface have great potential in many biosensor applications. Although various cellulose derivatives can form porous honeycomb structured materials, solubility issues and problems with film formation exist. To address this, we have generated robust cellulosic open-framework structures that can be post-functionalized through site-specific modification. Regioselectively modified amphiphilic cellulose azides, 3-O-azidopropoxypoly(ethylene glycol)-2,6-di-O-thexyldimethylsilyl cellulosics, were synthesized, and honeycomb-patterned films were readily produced by the simple breath figures method. Changing the degree of polymerization (DP) of the pendent ethylene glycol (EG(DP)) groups from 22 to 4 increased the corresponding honeycomb film pore diameters from ~1.2 to ~2.6 μm, enabling the potential tuning of pore size. Moreover, these novel azido-functionalized honeycomb films were easily functionalized using Cu(I)-catalyzed alkyne-azide [2 + 3] cycloaddition reaction; biotin was "clicked" onto the azide functionalized cellulosic honeycomb films without any effect to the film structure. These results indicate this system may serve as a platform for the design and development of biosensors.
authors.affiliation: Advanced Biomaterials Chemistry Laboratory, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
authors.forename: William Z
authors.initials: WZ
authors.lastname: Xu
authors.forename: Xinyue
authors.initials: X
authors.lastname: Zhang
authors.forename: John F
authors.initials: JF
authors.lastname: Kadla
mesh_terms: D000480:Alkynes / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D001710:Biotin / Q000737:chemistry; D002384:Catalysis; D002482:Cellulose / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D057930:Click Chemistry; D003300:Copper / Q000737:chemistry; D004867:Equipment Design; D019855:Ethylene Glycol / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis*; D016062:Porosity; D013237:Stereoisomerism; D013499:Surface Properties
chemical_list: D000480:Alkynes; D001386:Azides; D011108:Polymers; D001710:Biotin; D003300:Copper; D002482:Cellulose; D019855:Ethylene Glycol