Acta Chimica Sinica ›› 2014, Vol. 72 ›› Issue (1): 75-82.DOI: 10.6023/A13090931 Previous Articles     Next Articles



崔晓腾, 吕玉洋, 刘颖, 吴伯岳   

  1. 天津医科大学医学检验学院 天津 300203
  • 投稿日期:2013-09-05 发布日期:2013-11-14
  • 通讯作者: 吴伯岳,;Tel:022-60357168
  • 基金资助:

    项目受国家自然科学基金(No. 21205087)资助.

Aqueous Synthesis of Near-Infrared CdTe Quantum Dots for Biothiols Detection in Biological Fluids

Cui Xiaoteng, Lv Yuyang, Liu Ying, Wu Boyue   

  1. College of Laboratory Medicine, Tianjin Medicine University, Tianjin 300203
  • Received:2013-09-05 Published:2013-11-14
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21205087).

As well known that conventional aqueous synthesis of the near-infrared (NIR) CdTe quantum dots (QDs) using thiol ligands as capping reagents is usually very time-consuming. To overcome this defect and prepare NIR CdTe QDs, we present a fast and facile route in aqoueous phase under atmospheric pressure using L-cysteine (L-Cys) as capping reagents. The influences of various experimental conditions on the growth rate and luminescent properties of the obtained CdTe QDs have been systematically investigated, including Te-to-Cd ratio, L-Cys-to-Cd ratio and pH value. The experiment results suggested that lower ratio of Te:Cd or L-Cys:Cd and high pH value would markedly shortened the reaction time. Furthermore, the obtained QDs were used as a kind of NIR fluorescent probes for thiol detection in biological fluids. The change in the fluorescence intensity of the NIR CdTe QDs in the presence of 5.0 μmol·L-1 homocysteine (Hcy), L-Cys or glutathione (GSH) with different interaction time was measured. The effect of pH on the enhanced fluorescence intensity of the NIR CdTe QDs (10 mg·L-1) at 5.0 μmol·L-1 Hcy, L-Cys or GSH and the fluorescence responses of NIR CdTe QDs to 20 essential amino acids (5.0 mmol·L-1 for L-Cys, 5.0 mmol·L-1 for the other 19 amino acids) in pH 7.0 PBS buffer was investigated. The probe offered good sensitivity and selectivity for detecting L-Cys, Hcy and GSH in the presence of 20 other amino acids, main relevant metal ions, and some other molecules in biological fluids. The recovery of spiked 5.0 mmol·L-1 thiols in human serum and cell extracts ranged from 90% to 109%. The precision for 11 replicate measurements of the thiols at 5.0 mmol·L-1 is in the range of 2.4%~3.3%. The detection limits (3s) for L-Cys, Hcy and GSH are 43, 46 and 63 nmol·L-1, respectively. For real sample measurement, four serum samples and cell extract sample from two cancer cell lines (Hela and HepG2) were chosen and the analytical results were comparable with HPLC assay.

Key words: quantum dots, aqueous synthesis, near-infrared fluorescence, biothiol detection