Aqueous phase synthesis of CdTe quantum dots for biophotonics

Abstract

Over the past few years, CdTe quantum dots have been demonstrated as powerful probes for biophotonics applications. The aqueous phase synthesis technique remains the best approach to make high quality CdTe QDs in a single‐pot process. CdTe QDs prepared directly in the aqueous phase can have quantum yield as high as 80%. In addition, the surface of CdTe QDs prepared using the aqueous phase technique is functionalized with reactive groups that enable them to be directly conjugated with specific ligands for targeted delivery and sensing. In this contribution, we review recent progress in fabricating aqueous CdTe QDs and exploiting their optical properties in novel approaches to biomedical imaging and sensing applications. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

One‐Pot Synthesis of Dual‐Stabilizer‐Capped CdTe Nanocrystals with Efficient Near‐Infrared Photoluminescence and Electrochemiluminescence

“…[7][8][9] CdTe is an important small-band-gap material, and water-soluble visible-emitting CdTe NCs have been extensively prepared in aqueous media. [2] Because type-II NCs can demonstrate a longer PL wavelength than any of the single materials, [10,11] a large amount of aqueous synthetic methods have been carried out for type-II CdTe NCs including CdTe-based core/shell systems, [10] or alloys. [12] Although several type-II NIR-emitting CdTe NCs, such as CdTe/CdS, [13] CdTe/CdSe, [14] CdTe/ZnS, [15] CdHgTe, [16] and CdHgTe/CdS [17] have been synthesized, this strategy is still extremely challenging.…”

“…[1,2] NCs with photoluminescence (PL) in the nearinfrared (NIR) window, especially between 650 and 900 nm, are of particular interest for their possible sensing application since the auto-fluorescence and absorption from biological tissues are lowest in this spectral window. [3][4][5] Even though high-quality NIR-emitting NCs are usually achieved with multistep high-temperature organometallic approaches, [6] synthesizing NIR-emitting NCs in aqueous solution is arousing much attention.…”

Daunorubicin and gambogic acid coloaded cysteamine-CdTe quantum dots minimizing the multidrug resistance of lymphoma in vitro and in vivo

“…CdTe QDs have unique optical properties and have been widely used in simultaneous molecular/tissue imaging, cell labelling, in vivo tumor detection, and drug delivery applications. [19][20][21] With the aid of surface modification with cysteamine, GA and DNR could be facilely loaded onto the CdTe QDs through electronic interaction, resulting in high drug loading. Furthermore, GA can effectively bind to transferrin receptor -a type of protein overexpressed on the surface of different cancer cells, providing GA an additional ability to target cancer cells.…”

Accumulating advantages, reducing limitations: Multimodal nonlinear imaging in biomedical sciences – The synergy of multiple contrast mechanisms

“…Quantum dots made of CdTe are also bright, have broad excitation and narrow emission spectral widths and high photostability. In Figure 4 panel A macrophages have been labelled with green, red and yellow emitting CdTe/ZnTe quantum dots [71]. However, contrary to Cd an optimal marker for nonlinear contrast methods should be non toxic.…”

“…These improvements in comparison to linear microscopy are essential, e.g., for the investigation of neuronal signal transmission. For functional nonlinear imaging external labels are frequently used in animal models and cell cultures in order to increase the imaging speed due to higher signal yields and to facilitate tracking, e.g., of individual cells [71]. In the following illustrative examples of both application fields are presented, starting with structural, i.e., morphological and compositional, i.e., chemical or molecular imaging of different types of tissues generating detailed morphochemical maps, followed by state-of-the art imaging of dynamic processes.…”