Fluorescence Determination of Nitrite in Water Using Prawn-Shell Derived Nitrogen-Doped Carbon Nanodots as Fluorophores

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• 作者：Haimin Zhang ; Shenghong Kang ; Guozhong Wang ; Yunxia Zhang ; Huijun Zhao
• 刊名：ACS Sensor
• 出版年：2016
• 出版时间：July 22, 2016
• 年：2016
• 卷：1
• 期：7
• 页码：875-881
• 全文大小：599K
• ISSN：2379-3694

文摘

In this work, we report the synthesis of nitrogen (N)-doped carbon nanodots (N-CNDs) with an N doping level of 3.6 at. % by hydrothermal treatment of prawn shell and their application as fluorophores for selective and sensitive fluorescence detection of NOb>2b>^– in water. The results demonstrate that NOb>2b>^– detection by directly fluorescent quenching at N-CNDs fluorophores can achieve an analytical detection linear range up to 1.0 mM with a detection limit of 1.0 μM. The obtained detection limit of NOb>2b>^– using N-CNDs fluorophores is dramatically lower than the maximum limit value of 3.0 mg L^–1 (namely, 65 μM) for NOb>2b>^– in drinking water ruled by the World Health Organization (WHO), which is very important for a practical application of the developed analytical method. The interference experiments indicate that only I^– ions among all common anions and cations investigated show very adverse influence on selective detection of NOb>2b>^– by this developed N-CNDs based fluorescent determination method. Further, the fluorescence quenching of N-CNDs on NOb>2b>^– concentrations under the given experimental conditions fits a linear Stern–Volmer relationship very well, indicating a dynamic quenching process in this N-CNDs/NOb>2b>^– fluorescence sensing system. A fluorescent quenching mechanism resulted from the redox reaction between the excited oxidation state of N-CNDs under light excitation and NOb>2b>^– was proposed based on the experimental results. The findings in this work exhibit the great potential using cheap and abundant biomass-derived N-doped carbon nanodots as fluorophores for selective and sensitive determination of environmentally harmful anions.