Determination of TNT explosive based on its selectively interaction with creatinine-capped CdSe/ZnS quantum dots

• Creatinine-modified CdSe/ZnS quantum dots fluorescent probe has been prepared.
• This modified QDs has been used for sensing 2,4,6,-trinitrotoluene explosive (TNT).
• The selectivity of fluorescence quenching of creatinine-QD for TNT has been evaluated.
• The potential application of the proposed methodology for the determination of TNT in spiked soils has been demonstrated.

Here, a creatinine-modified CdSe/ZnS quantum dots fluorescent probe has been prepared and used for sensing 2,4,6,-trinitrotoluene explosive (TNT). The proposed method is based on the selective interaction between creatinine and nitroaromatic compounds according to the well-known Jaffé reaction. The procedure for the synthesis of creatinine-CdSe/ZnS reagent is very simple and reproducible and its fluorescent characteristics are reported. We found that the presence of TNT quenches the original fluorescence of creatinine-QD according to the Stern–Volmer model. Under the working conditions, the calibration plot of Io/I versus concentration of TNT was linear in the range 10–300 μg L−1 (R2 = 0.996). The mechanism interaction is discussed. The selectivity of fluorescence quenching of creatinine-QD for TNT has been evaluated. Finally, the potential application of the proposed methodology for the determination of TNT in spiked soils is demonstrated. For the analysis of soil samples a solid-liquid extraction is carried out and a four-point standard addition protocol is used to correct the matrix effect. The method, which is simple and rapid, allows the detection of 0.057 μg g−1 of TNT in soil samples. This sensor could be a useful tool for environmental studies, a crucial topic for nanotechnology nowadays.

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