Method for detecting Cr2O7<2-> by fluorescent carbon dots synthesized with magnolia grandiflora leaves as carbon source

The invention discloses a method for selectively detecting Cr2O7 in a solution system by fluorescent carbon dots synthesized with magnolia grandiflora leaves as a carbon source. The method comprises a specific process as follows: selective recognition and quantitative detection of Cr2O7 in the Cr2O7 solution system are realized through the fluorescent carbon dots synthesized with the magnolia grandiflora leaves as the carbon source on a fluorescence spectrophotometer, lambda ex is equal to 340 nm and lambda em is equal to 435 nm in the detection process, firstly, the fluorescent carbon dots are synthesized and added to a to-be-detected solution, a fluorescence intensity-Cr2O7 concentration standard curve is drawn according to fluorescence intensity of the fluorescent carbondots in a Cr2O7 standard solution with known gradient concentration, and the concentration of Cr2O7 in the to-be-detected Cr2O7 solution is obtained according to the fluorescence intensity of the to-be-detected C