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

Abstract

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 NO2– in water. The results demonstrate that NO2– 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 NO2– using N-CNDs fluorophores is dramatically lower than the maximum limit value of 3.0 mg L–1 (namely, 65 μM) for NO2– 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 NO2– by this developed N-CNDs based fluorescent determination method. Further, the fluores...