Title: The effects of QD stabilizer structures on pH dependence, fluorescence characteristics, and QD sizes
Abstract: CdTe quantum dots (QDs) were prepared in aqueous solution using various mercaptocarboxylic acids such as mercaptopropionic acid (MPA), mercaptoethylamine (MEA), and L-cysteine (L-Cys) as stabilizing agents. The pH control of QD suspensions is essential when using fluorescent QDs in biological systems. The pH-dependent photoluminescence (PL) of MPA- and L-Cys-stabilized CdTe QDs was systematically investigated. Experimental results showed that CdTe-L-Cys is effective within a wider pH range than CdTe-MPA and CdTe-MEA, although it is ineffective in the vicinity of the isoelectric point, which makes CdTe-L-Cys quantum dots potentially suitable as a biological labeling probe under physiological conditions. Meanwhile, the effect of stabilizer structure on QD size was studied by comparing CdTe-MPA and CdTe-L-Cys QDs using x-ray diffraction, x-ray photoelectron spectroscopy and transmission electron microscopy. The results indicated that the coordination of amines with cadmium reduced the activity of Cd precursors, and the coordination of S with the CdTe QDs affected their crystal structure, resulting in the formation of relatively large CdTe-L-Cys quantum dots.
Publication Year: 2018
Publication Date: 2018-05-31
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 7
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