An Non-metallic Nitrite Electrochemical Sensor Based on In-situ Growth of Carbon Dots on Carbon Cloth

The metals and metal compounds used to construct nitrite sensors dissolve into the solution during operation due to reactions, which not only pollutes the environment but also affects the long-term stability of the sensor. Hence, This study developed a stable and sensitive non-metallic based nitrite electrochemical sensor by directly growing carbon dots(CDs) in situ on carbon cloth(CC) using citric acid and ethylenediamine as precursors. The growth of CDs on CC was confirmed through inverted fluorescence microscopy, transmission electron microscope, and X-ray photoelectron spectrometer. The CDs/CC electrode material, rich in hydrophilic functional groups, enhances contact between the electrode and electrolyte, significantly improving electrical conductivity, active specific surface area and the quantity of active sites on the electrode material. The electrochemical performance results showed that the synergistic effects between the CDs and CC significantly enhanced the electrocatalytic activity toward nitrite. Nitrite detection was achieved high sensitivity, with a detection limit of 0.14 μM. The sensor's performance was further validated by analyzing nitrite in ham sausage, achieving recoveries between 97.72% and 101.40%. This study proposes a new method for manufacturing flexible electrochemical sensors that respond to different target objects by growing different carbon dots on carbon cloth.