Using Onion for Green Synthesis of N-CQDs as Nanosensor for Detection and Determination of Nitrite

Adding heteroatoms to carbon quantum dots can improve their structural and optical properties and also its applications in extent areas. In this work N-doped carbon quantum dots N-CQDs were synthesized by green method as fluorescence sensors for determination and detection of nitrite. In the green method onion and N,N-Diisopropylethylamine were combined in a hydrothermal way. The product was characterized by FT-IR and also Optical properties and photoluminescent properties of them were studied by UV-visible and Photoluminescence spectrometry respectively. The size of the result N-CQDs was estimated less than 10 nm utilizing TEM. As the concentration of the analyte nitrite was increased, the fluorescent intensity of the N-CQDs was decreased in a linear order due to the quenching mechanism. Under optimum laboratory conditions time 30 minutes and Acidic pH, the concentration range of N-CQDs for determination of nitrite was 0.014-2142.85 µM, LOD 0.008 µM and R2 was equaled to 0.989.