Borse Vivek, Kashikar Adisha, Srivastava Rohit
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay (IIT B), Powai, Mumbai 400076, India.
J Nanosci Nanotechnol. 2018 Apr 1;18(4):2582-2591. doi: 10.1166/jnn.2018.14315.
Quantum dots are the semiconductor nanocrystals having unique optical and electronic properties. Quantum dots are category of fluorescent labels utilized for biological tagging, biosensing, bioassays, bioimaging and in vivo imaging as they exhibit very small size, signal brightness, photostability, tuning of light emission range, longer photoluminescence decay time as compared to organic dyes. In this work, we have synthesized and characterized mercaptopropionic acid capped cadmium telluride quantum dots (MPA-CdTe QDs) using hydrothermal method. The study further reports fluorescence intensity stability of quantum dots suspended in different buffers of varying concentration (1-100 mM), stored at various photophysical conditions. Fluorescence intensity values were reduced with increase in buffer concentration. When the samples were stored at room temperature in ambient light condition the quantum dots suspended in different buffers lost the fluorescence intensity after day 15 (except TRIS II). Fluorescence intensity values were found stable for more than 30 days when the samples were stored in dark condition. Samples stored in refrigerator displayed modest fluorescence intensity even after 300 days of storage. Thus, storage of MPA-CdTe QDs in refrigerator may be the suitable choice to maintain its fluorescence stability for longer time for further application.
量子点是具有独特光学和电子特性的半导体纳米晶体。量子点是一类用于生物标记、生物传感、生物测定、生物成像和体内成像的荧光标记物，因为与有机染料相比，它们具有非常小的尺寸、信号亮度、光稳定性、发光范围可调、光致发光衰减时间更长等特点。在这项工作中，我们采用水热法合成并表征了巯基丙酸包覆的碲化镉量子点（MPA-CdTe QDs）。该研究进一步报道了悬浮在不同浓度（1-100 mM）的不同缓冲液中、在各种光物理条件下储存的量子点的荧光强度稳定性。荧光强度值随缓冲液浓度的增加而降低。当样品在室温下于环境光条件下储存时，悬浮在不同缓冲液中的量子点在第15天后失去荧光强度（TRIS II除外）。当样品在黑暗条件下储存时，荧光强度值在30多天内保持稳定。即使在储存300天后，储存在冰箱中的样品仍显示出适度的荧光强度。因此，将MPA-CdTe QDs储存在冰箱中可能是保持其荧光稳定性以便长时间进一步应用的合适选择。
