Synthesis And Application Of Functionalized Black Phosphorus Quantum Dots In Soil Analysis

At present,there are many kinds of pollution in the soil,including organic matter pollution and heavy metal pollution.The analysis and detection methods of organic matter and heavy metal are emerging in endlessly.Electrochemiluminescence technology is a technology that has the advantages of easy operation and controllability.Over the past few decades,there has been considerable interest in it from the point of view of sensitivity,simple settings,and good control.Quantum dots have size-dependent characteristics and are widely used in environmental detection,immunodetection,various fluorescence,biosensing and other fields,and have attracted attention.In recent years,quantum dots are ECL emitters,which are novel,attracting attention and research.As we all know,the ECL properties of quantum dots have a great correlation with surface states.Some appropriate modifications to the surface of quantum dots can not only significantly enhance the luminescence performance of quantum dots,but also realize molecular recognition of different species.This thesis is based on solvothermal synthesis of black phosphorous quantum dots(BPQDs),synthesis of cyclodextrin cross-linked chitosan complex(CS-?-CD).Fluorescence spectroscopy(FL),ultraviolet-visible absorption spectroscopy(UV-vis),high-resolution transmission electron microscopy(HRTEM)and other methods are used to characterize the properties of nanomaterials such as black phosphorous quantum dots.ECL analysis system(MPI-E)and electrochemistry are used.Methods such as alternating current impedance(EIS)characterize the construction of the sensor.The main contents are as follows:A novel quantum dot fluorescent probe was constructed to detect lead ions in soil.BPQDs with negative charge,chitosan with positive charge and xylenol orange(XO)with negative charge were assembled on BPQDs surface based on layer by layer self-assembly technology,and a fluorescent probe with high sensitivity to Pb2+ was synthesized.The properties of nanomaterials were characterized by fluorescence spectroscopy(FL),which proved that the functional BPQDs were successfully prepared.The linear range of the BPQDs was 0.2?5.0 ?mol/L and the detection limit was 0.067 ?mol/L.The BPQDs was successfully used to analyze the content of Pb2+,further expand BPQDs in the field of fluorescence sensing application prospects.An electrochemiluminescence sensor based on black phosphorus quantum dots was developed to detect BaP.The black phosphorus quantum dots were combined with CS-?-CD by electrostatic action,and the BPQDs ECL luminescence was stable in phosphate buffer containing potassium persulfate by the classical potassium persulfate co-reaction agent.It has the function of specific recognition of benzo[a]pyrene,and the host-guest recognition of cyclodextrin and target BaP is used to lead to the change of assembly resistance on the surface of the glass carbon electrode,thus the corresponding change of ECL signal intensity.The detection concentration of BaP ranged from 2×10-9 mol/L to 2×10-7 mol/L.At low concentration,the linear equation was y=258.269x-82.883(R2=0.998).At high concentration,the linear equation was y=10.693x-2419.661(R2=0.990).The detection limit was 0.935×10-9 mol/L(S/N=3).Figure[22]Table[7]Reference[131]...