title: Multifunctional and High Affinity Polymer Ligand that Provides Bio-Orthogonal Coating of Quantum Dots.
abstract: We detail the design of hydrophilic metal-coordinating ligands and their use for the effective coating of luminescent quantum dots (QDs). The ligand design exploits the specific, reagent-free nucleophilic addition reaction of amine-modified molecules toward maleic anhydride to introduce several lipoic acid metal anchors, hydrophilic zwitterion moieties, and specific reactive groups along a poly(isobutylene-alt-maleic anhydride) (PIMA) chain. Tunable reactive groups tested in this study include azide, biotin, carboxyl, and amine. Cap exchange with these multilipoic acid ligands via a photochemical ligation strategy yields homogeneous QD dispersions that are colloidally stable over several biologically relevant conditions and for extended periods of time. The zwitterionic coating yields compact nanoparticle size and imparts nonsticky surface properties onto the QDs, preventing protein absorption. The introduction of a controllable number of reactive groups allows conjugation of the QDs to biomolecules via bio-orthogonal coupling chemistries including (1) attachment of the neurotransmitter dopamine to QDs via amine-isothiocyanate reaction to produce a platform capable of probing interactions with cysteine in proteins, based on charge transfer interactions; (2) self-assembly of biotinylated QDs with streptavidin-dye; and (3) ligation of azide-functionalized QDs to cyclooctyne-modified transferrin via copper-free click chemistry, used for intracellular delivery. This ligand design strategy can be used to prepare an array of metal-coordinating ligands adapted for coating other inorganic nanoparticles, including magnetic and plasmonic nanomaterials.
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.
authors.forename: Wentao
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.
authors.forename: Anshika
authors.initials: A
authors.lastname: Kapur
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.
authors.forename: Xin
authors.initials: X
authors.lastname: Ji
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.|Department of Material Science and Engineering, Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University , Xiamen, Fujian 361005, PR China.
authors.forename: Birong
authors.initials: B
authors.lastname: Zeng
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Mishra
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.
authors.forename: Hedi
authors.initials: H
authors.lastname: Mattoussi
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D001710:Biotin / Q000737:chemistry; D004298:Dopamine / Q000737:chemistry; D006639:Histidine / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D008299:Maleic Anhydrides / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014168:Transferrin / Q000032:analysis / Q000737:chemistry
chemical_list: D008024:Ligands; D008299:Maleic Anhydrides; D011108:Polymers; D013438:Sulfhydryl Compounds; D014168:Transferrin; C000609390:poly(isobutylene-alt-maleic anhydride); C033223:polyhistidine; D006639:Histidine; D001710:Biotin; D019809:Streptavidin; D004298:Dopamine