Micelle-templated composite quantum dots for super-resolution imaging

• Published in: Nanotechnology Vol. 25; no. 19; p. 195601
• Main Authors: Xu, Jianquan, Fan, Qirui, Mahajan, Kalpesh D, Ruan, Gang, Herrington, Andrew, Tehrani, Kayvan F, Kner, Peter, Winter, Jessica O
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 16.05.2014; Institute of Physics
• Subjects: Applied sciences; Blinking; Chemical synthesis methods; Cross-disciplinary physics: materials science; rheology; doping; Electronics; Exact sciences and technology; Fluorescence; Imaging; Manganese; Manganese Compounds - chemistry; Materials science; Methods of nanofabrication; Micelles; Microscopy, Fluorescence; Molecular electronics, nanoelectronics; Nanocomposites - chemistry; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Particulate composites; Physics; Quantum dots; Quantum Dots - chemistry; Selenium Compounds - chemistry; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Shells; Signal-To-Noise Ratio; Stability; superresolution imaging; Zinc Compounds - chemistry; Encapsulation; Energy levels; Brightness; Quantum dots; Core shell structure; Doping; Fluorescence; Signal-to-noise ratio; Template reaction; Surface treatments; Manganese additions; Composite materials; Nanocomposites; II-VI semiconductors; Imaging; Micelles; Oxidation; Nanostructured materials; Biomedical imaging
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/25/19/195601

Quantum dots (QDs) have tremendous potential for biomedical imaging, including super-resolution techniques that permit imaging below the diffraction limit. However, most QDs are produced via organic methods, and hence require surface treatment to render them water-soluble for biological applications. Previously, we reported a micelle-templating method that yields nanocomposites containing multiple core shell ZnS-CdSe QDs within the same nanocarrier, increasing overall particle brightness and virtually eliminating QD blinking. Here, this technique is extended to the encapsulation of Mn-doped ZnSe QDs (Mn-ZnSe QDs), which have potential applications in super-resolution imaging as a result of the introduction of Mn2+ dopant energy levels. The size, shape and fluorescence characteristics of these doped QD-micelles were compared to those of micelles created using core shell ZnS-CdSe QDs (ZnS-CdSe QD-micelles). Additionally, the stability of both types of particles to photo-oxidation was investigated. Compared to commercial QDs, micelle-templated QDs demonstrated superior fluorescence intensity, higher signal-to-noise ratios, and greater stability against photo-oxidization,while reducing blinking. Additionally, the fluorescence of doped QD-micelles could be modulated from a bright 'on' state to a dark 'off' state, with a modulation depth of up to 76%, suggesting the potential of doped QD-micelles for applications in super-resolution imaging.