Hidden Properties of Carbon Dots Revealed After HPLC Fractionation
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- 作者：John C. Vinci ; Ivonne M. Ferrer ; Steven J. Seedhouse ; Allen K. Bourdon ; Justin M. Reynard ; Barbara A. Foster ; Frank V. Bright ; Luis A. Col贸n
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2013
- 出版时间：January 17, 2013
- 年：2013
- 卷：4
- 期：2
- 页码：239-243
- 全文大小：324K
- 年卷期：v.4,no.2(January 17, 2013)
- ISSN：1948-7185
文摘
Carbon dots (C-dots) are often synthesized, modified, and studied as a mixture. Unfortunately, the spectroscopic and biological properties measured for such C-dots assume that there is a high degree of homogeneity in the produced sample. By means of high-resolution separation techniques, we show that 鈥渁s-synthesized鈥?C-dots exist as a relatively complex mixture and that an unprecedented reduction in such complexity can reveal fractions of C-dots with unique luminescence properties. The wavelength-dependent photoluminescence commonly assigned as an inherent property of C-dots is not present in fractionated samples. While ultraviolet鈥搗isible absorption profiles reported for C-dots are typically featureless, we have found fractions of C-dots possessing unique absorption bands, with different fractions possessing specific emission wavelengths. Furthermore, fractionated C-dots showed profound differences in emission quantum yield, allowing for brighter C-dots to be isolated from an apparent low quantum yield mixture. These more luminescent fractions of C-dots displayed improved biological compatibility and usefulness as cellular imaging probes.