Aqueous quantum dots with high fluorescence, colloidal stability and biocompatibility encapsulated by an amphiphilic fluorine copolymer. (28th September 2019)

• Record Type: Journal Article
• Authors: Yang, Kai; Luo, Guanzhou; Zeng, Xinjuan; Xu, Mengyi; Pi, Pihui; Xu, Shouping; Wen, Xiufang
• Is Part Of: Polymer. Volume 179(2019)
• Publication Date: 2019-09-28
• Subjects: Amphiphilic fluorine copolymers -- Stable -- Nonspecific binding -- Fluorescent probes; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2019.121706
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Quantum dots (QDs) encapsulated by amphiphilic fluorine copolymers have shown great promise as molecular probes for bio-imaging. Here, a series of amphiphilic fluorine copolymers, methoxypolyethylene glycols-block-poly (2-(diethylamino)ethyl methacrylate)-block-poly (2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate) (O m A n F p ), were successfully coated on the surface of semi conductive quantum dots (QDs) to overcome their stability issues in aqueous solution. The hydrodynamic diameters (Dh, DLS ) of theseO m A n F p encapsulated QDs (O m A n F p @QDs) can be tuned between 40 nm and 61 nm by choosing amphiphilic fluorine copolymers with different hydrophobic portions. The obtainedO m A n F p @QDs colloids are found stable over a wide pH range (4.0–12.0) with no sign of aggregation. In the pH range of 4.0–7.0, the repulsion of blockO and cationic blockA onO m A n F p @QDs contributes to the colloids' stability in aqueous solution. The protonation of blockA also leads to the decrease of Dh, DLS from 61 to 51 nm and the enhancement of the transmittance ofO 113 A 11 F 19 @QDs solution from 78% to 92%. In the pH range from 8.0 to 12.0, the repulsion between the strong hydrated blockO makesO m A n F p @QDs nanoparticles stable with deprotonated hydrophobic blockA . The fluorescent quantum yield properties of QDs are well preserved inO m A n F p @QDs aqueous solution due to the protection of blockF wrapping tightly around the QDs cores. The photoluminescence quantum yield (PL QY) is found reserved better under basic conditions due to the co-encapsulation of hydrophobic blockA . The PL intensity ofO m A n F p @QDs in 400 mM NaCl solution changes only slightly. BlockO andF in the polymer offerO m A n F p @QDs with good biocompatibility and low levels of nonspecific binding to bovine serum albumin proteins (BSA). These advantages renderO m A n F p @QDs an attractive candidate as ideal fluorescent probes in advanced biomedical imaging studies. Graphical abstract: Image 1 Highlights: Novel amphiphilic fluorine copolymersO m A n F p were synthesized. Oleylamine-capped CdSe encapsulated byO m A n F p (O m A n F p @QDs) was successfully transfered from CHCl3 to water. The hydrodynamic diameters ofO m A n F p @QDs were tunable. O m A n F p @QDs were colloidally stable in aqueous solution. O m A n F p @QDs exhibited low levels of nonspecific binding to proteins.