Optical properties of pH-sensitive carbon-dots with different modifications

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• 作者：Weiguang Kong ; Huizhen Wu ; Zhenyu Ye ; Ruifeng Li ; Tianning Xu ; Bingpo Zhang
• 关键词：Carbon dots ; Surface modification ; pH measurement ; Bio-imaging ; Colloid
• 刊名：Journal of Luminescence
• 出版年：April, 2014
• 年：2014
• 卷：148
• 期：Complete
• 页码：238-242
• 全文大小：1034 K

文摘

Carbon dots with unique characters of chemical inertness, low cytotoxicity and good biocompatibility, demonstrate important applications in biology and optoelectronics. In this paper we report the optical properties of pH-sensitive carbon dots with different surface modifications. The as-prepared carbon dots can be well dispersed in water by modifying with acid, alkali or metal ions though they tend to form a suspension when being directly dispersed in water. We find that the carbon dots dispersed in water show a new emission and absorption character which is tunable due to the pH-sensitive nature. It is firstly proved that the addition of bivalent copper ions offers a high color contrast for visual colorimetric assays for pH measurement. The effect of surface defects with different modification on the performances of the carbon dots is also explored with a core-shell model. The hydro-dispersed carbon dots can be potentially utilized for cellular imaging or metal ion probes in biochemistry.