title: Characterization of phthalocyanine functionalized quantum dots by dynamic light scattering, laser Doppler, and capillary electrophoresis.
abstract: In this work, we characterized different phtalocyanine-capped core/shell/shell quantum dots (QDs) in terms of stability, ζ-potential, and size at various pH and ionic strengths, by means of capillary electrophoresis (CE), and compared these results to the ones obtained by laser Doppler electrophoresis (LDE) and dynamic light scattering (DLS). The effect of the phthalocyanine metallic center (Zn, Al, or In), the number (one or four), and nature of substituents (carboxyphenoxy- or sulfonated-) of functionalization on the phthalocyanine physicochemical properties were evaluated. Whereas QDs capped with zinc mono-carboxyphenoxy-phtalocyanine (ZnMCPPc-QDs) remained aggregated in the whole analyzed pH range, even at low ionic strength, QDs capped with zinc tetracarboxyphenoxy phtalocyanine (ZnTPPc-QDs) were easily dispersed in buffers at pH equal to or higher than 7.4. QDs capped with aluminum tetrasulfonated phthalocyanine (AlTSPPc-QDs) and indium tetracarboxyphenoxy phthalocyanines (InTCPPc-QDs) were stable in aqueous suspension only at pH higher than 9.0 due to the presence of functional groups bound to the metallic center of the phthalocyanine. The ζ-potential values determined by CE for all the samples decreased when ionic strength increased, being well correlated with the aggregation of the nanoconjugates at elevated salt concentrations. The use of electrokinetic methodologies has provided insights into the colloidal stability of the photosensitizer-functionalized QDs in physiological relevant solutions and thereby, its usefulness for improving their design and applications for photodynamic therapy. Graphical Abstract Schematic illustration of the phthalocyanine capped QDs nanoconjugates and the capillary electrophoresis methods applied for size and ζ-potential characterization.
authors.affiliation: Chimie ParisTech, PSL Research University, Unite de Technologies Chimiques et Biologiques pour la Sante UTCBS, 75005, Paris, France.|INSERM, UTCBS, U 1022, 75006, Paris, France.|CNRS, UTCBS UMR 8258, 75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cite, UTCBS, 75006, Paris, France.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Ramírez-García
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown, 6140, South Africa.
authors.forename: David O
authors.initials: DO
authors.lastname: Oluwole
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown, 6140, South Africa.
authors.forename: Siphesihle Robin
authors.initials: SR
authors.lastname: Nxele
authors.affiliation: Chimie ParisTech, PSL Research University, Unite de Technologies Chimiques et Biologiques pour la Sante UTCBS, 75005, Paris, France.|INSERM, UTCBS, U 1022, 75006, Paris, France.|CNRS, UTCBS UMR 8258, 75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cite, UTCBS, 75006, Paris, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: d'Orlyé
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown, 6140, South Africa.
authors.forename: Tebello
authors.initials: T
authors.lastname: Nyokong
authors.affiliation: Chimie ParisTech, PSL Research University, Unite de Technologies Chimiques et Biologiques pour la Sante UTCBS, 75005, Paris, France. fethi.bedioui@chimieparistech.fr.|INSERM, UTCBS, U 1022, 75006, Paris, France. fethi.bedioui@chimieparistech.fr.|CNRS, UTCBS UMR 8258, 75006, Paris, France. fethi.bedioui@chimieparistech.fr.|Université Paris Descartes, Sorbonne Paris Cite, UTCBS, 75006, Paris, France. fethi.bedioui@chimieparistech.fr.
authors.forename: Fethi
authors.initials: F
authors.lastname: Bedioui
authors.affiliation: Chimie ParisTech, PSL Research University, Unite de Technologies Chimiques et Biologiques pour la Sante UTCBS, 75005, Paris, France. anne-varenne@chimie-paristech.fr.|INSERM, UTCBS, U 1022, 75006, Paris, France. anne-varenne@chimie-paristech.fr.|CNRS, UTCBS UMR 8258, 75006, Paris, France. anne-varenne@chimie-paristech.fr.|Université Paris Descartes, Sorbonne Paris Cite, UTCBS, 75006, Paris, France. anne-varenne@chimie-paristech.fr.
authors.forename: Anne
authors.initials: A
authors.lastname: Varenne
mesh_terms: D000067493:Dynamic Light Scattering / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods; D007204:Indium / Q000737:chemistry; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D007834:Lasers; D008670:Metals / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D009994:Osmolar Concentration; D010316:Particle Size; D045663:Quantum Dots / Q000737:chemistry*; D055672:Static Electricity; D015032:Zinc / Q000737:chemistry
chemical_list: D007211:Indoles; D054833:Isoindoles; D008670:Metals; D009942:Organometallic Compounds; D007204:Indium; C060570:aluminum phthalocyanine; D015032:Zinc; C013647:phthalocyanine
keywords: Capillary electrophoresis; Colloidal stability; Photodynamic therapy; Photosensitizers; Phthalocyanines; Quantum dots