Nitrogen Doped Carbon Dots Derived from Natural Seeds and Their Application for Electrochemical Sensing

In this work, nitrogen doped carbon dots (N-CDs) derived from kiwi seeds, white sesame seeds, and black sesame seeds were prepared by a simple, feasible and green route. Then a novel nitrite electrochemical sensor was successfully constructed. The morphology and composition of N-CDs were characterized by Field emission transmission electron microscopy, Fourier transform infrared spectra, Raman spectra and electrochemical methods. The particle size of the as-prepared N-CDs from the three kinds of natural seeds were in the range of 1.4 ∼ 4.9 nm, 1.4 ∼ 4.6 nm, and 1.2 ∼ 4.7 nm, respectively. Moreover, these N-CDs nanomaterials exhibited excellent electrocatalytic performances for nitrite sensing with a detection limit of 0.23 μM (S/N = 3) by electrochemical methods. Additionally, the stability, anti-interference ability and real sample analysis of the sensors had been evaluated. Finally, the electrochemical sensor was successfully applied for nitrite determination in real samples (ham sausages). Based on the present study, more natural seeds could be expected as preferred candidates for N-CDs synthesis, and a general platform of novel electrochemical sensors for nitrite detection is provided.