LAUSR

A novel nitrogen-doped fluorescent carbon dots was successfully prepared via a simple onestep hydrothermal method using the medicinal plant Pinellia ternata as an environment-friendly carboncontaining precursor for the first time and ethylenediamine as nitrogen source. The diameter, morphology, ultimate composition and optical performance of the prepared Pinellia ternata nitrogendoped carbon quantum dots (N-CQDs) were characterized by a series of analytical characterization techniques. The photostability was also investigated through the conditions of ionic strength, pH, and storage time. The obtained results showed that the particle size distribution of Pinellia ternata-based NCQDs was uniform with the fluorescence quantum yield as high as 21.3%, and it also exhibited good excitation dependence and excellent light stability. Based on the fluorescence quenching mechanism of fluorescent inner filter effect, it has high sensitivity, selectivity and anti-interference ability for chromium (VI). Under optimal working conditions, the nanoprobe showed a good and sensitive linear response (R = 0.9955) toward chromium (VI) within the concentration range of 0~200 μM with a low detection limit of 15 nM. This method has been successfully applied to the detection of chromium (VI) in environmental water samples, providing a new idea for the development of green natural compound carbon materials.