Controlled transformation of aqueous CdTe quantum dots → Te-rich CdTe nanorods → second CdTe QDs

Abstract

The transformation of existing inorganic nanomaterials from one structure into another represents a straightforward, versatile and effective approach for the synthesis of nanomaterials. Hence, in this paper, we focus on the controlled transformation of water-soluble CdTe quantum dots (QDs) A Terich CdTe nanaorods (NRs) A second CdTe QDs. It was found that in the presence of L-cysteine (Lcys), aqueous thiolglycolic acid (TGA)-stabilized CdTe QDs might spontaneously assemble and recrystallize into luminescent Te-rich CdTe nanorods under ambient conditions. However, increasing the temperature of the nanorod dispersion to 90 uC or adding a specific amount of TGA into the dispersion of NRs might effectively induce the transformation of Te-rich CdTe NRs A second CdTe QDs. These unique transformation processes that involve simultaneous complicated changes in the chemical compositions, structures and morphologies of nanocrystals were systematically characterized by optical techniques, transmission electron microscopy (TEM) and powder X-ray diffractometry (XRD).

Highly luminescent water-soluble quaternary Zn–Ag–In–S quantum dots for tumor cell-targeted imaging

“…[15][16][17][18][19] And, the precursors Ag + and S 2À are much more stable than Cu + and Se 2À , Te 2À in water under air. [20][21][22] Thus, AgInS 2 -based QDs may provide excellent band-gap tunability in the visible region, and can be produced directly in air (without the protection of N 2 ). However, unfortunately, these produced naked I-III-VI 2 QDs usually exhibited weak PL emission.…”

Planar Se multipod crystals with unusual growth directions: thoughts on the spontaneous growth of hexagonal Se

“…S7 †), including four kinds of small molecules containing a carboxyl group (-COOH) such as acetic acid, succinic acid, glutaric acid, and EDTA, and two kinds of small molecules with a hydroxyl (-OH), mercapto and amido (-SH and -NH 2 ) group, namely glycerol and mercaptamine. 30,[37][38][39] When the four kinds of small molecules containing a carboxyl group were used to replace TSC in the preparation of Se crystals, similar branched structures could be observed in all cases (Fig. S8 †).…”

Water-soluble Zn–Ag–In–Se quantum dots with bright and widely tunable emission for biomedical optical imaging

“…Water-soluble CdTe QDs with red PL emission were prepared according to our previously reported method. 28 Human malignant glioma cell line (U87MG), human breast cancer cell line (MCF-7) and normal human liver cell line (L02) were purchased from American Type Culture Collection (ATCC, Manassas, VA, USA). BALB/c nude mice bearing U87MG tumors were purchased from KeyGEN Biotech.…”