Zhao Fei, Kim Inyea, Kim Jongsung
J Nanosci Nanotechnol. 2014 Aug;14(8):5650-3. doi: 10.1166/jnn.2014.8309.
During the past decade, there has been a lot of research on the application of quantum dots (QDs) in photonics and biotechnology. QDs are semiconductor nanocrystals which show many peculiar optical and electrical properties due to their quantum confinement effects. In this work, the correlation of the fluorescence intensity of QDs and the pH under ambient temperature was studied. An optical fiber pH sensor was prepared using CdSe/ZnS carboxyl quantum dots as sensing media. QDs with different sizes and emission colors (green, yellow, and red) were immobilized on the surface of the optical fiber through EDC/sulfo-NHS coupling reaction. The optical fiber was immersed in water, and the photoluminescence (PL) spectra of QDs were obtained at ambient temperature under various pH conditions. The photoluminescence (PL) intensity of QDs increased linearly with the increase of pH, and among the QDs, the red emitting QDs show the largest change in PL intensity with pH. This shows that QDs can be used as pH sensing media and optical fiber pH probe can be prepared.
在过去十年中，对量子点（QDs）在光子学和生物技术中的应用进行了大量研究。量子点是半导体纳米晶体，由于其量子限制效应而表现出许多独特的光学和电学性质。在这项工作中，研究了室温下量子点荧光强度与pH值的相关性。以CdSe/ZnS羧基量子点为传感介质制备了一种光纤pH传感器。通过EDC/磺基-NHS偶联反应将不同尺寸和发射颜色（绿色、黄色和红色）的量子点固定在光纤表面。将光纤浸入水中，在室温下不同pH条件下获得量子点的光致发光（PL）光谱。量子点的光致发光（PL）强度随pH值的增加呈线性增加，并且在这些量子点中，红色发射量子点的PL强度随pH值的变化最大。这表明量子点可作为pH传感介质，并且可以制备光纤pH探针。
