Application Of Chemiluminescence Analysis Based On The Catalytic Properties Of Black Phosphorus Quantum Dots

In recent years,black phosphorus quantum dots（BP QDs）have been widely studied,with the advantages of unique structure,excellent photoelectric properties and good biocompatibility.In this thesis,we mainly focus on the catalytic properties of black phosphorus quantum dots and Ag@BP QDs in the field of chemiluminescence（CL）.The CL signal of luminol system was enhanced by the catalytic activity of both.Ag@BP QDs were successfully prepared by chemical modification of Ag+ to generate silver "shells" around the BP QDs,which effectively enhanced the stability and catalytic activity of BP QDs.Based on the catalytic activity of BP QDs and Ag@BP QDs,simple CL analysis detection platforms for dection of Co（Ⅱ）,alpha-glycosidase and acarbose were established.The applications of these methods have practical value in environmental detection,as well as enzyme activity evaluation.The detailed contents are as follows:Part one.Luminol chemiluminescence system for cobalt（Ⅱ）detection based on catalytic properties of black phosphorus quantum dotsBright yellow BP QDs dispersion solution was successfully prepared according to a previous solvothermal strategy.The CL properties of BP QDs have been studied.Under alkaline condition,BP QDs can enhance luminol CL system without additional oxidant.A possible reaction mechanism is proposed by the study of CL spectrum,ultraviolet-visible absorption spectra,electron paramagnetic resonance spectra as well as radical scavenging experiments.BP QDs catalyze dissolve oxygen to generate a large amount of reactive oxygen radicals（ROS,1O2,O2·-and·OH）.These reactive oxygen radicals oxidize luminol to generate an excited state of 3-aminophthalate,which returns back to ground state and emits CL with the maximum wavelength at 425 nm.These radicals were reported to react with cobalt（Ⅱ）ion to form high active cobalt-ROS complex.The formed complexes are important intermediates in luminol reaction and enhance the CL emission of luminol reaction.The enhanced CL intensity（ΔI）exhibits an excellent linear response for cobalt（Ⅱ）ion from 2.5 to 2000.0 pmol/L.The linear regression equation is ΔI=1.46 cobalt（Ⅱ）ion（pmol/L）+29.03.The limit of detection is calculated to be 0.7 pmol/L（3sb/S）.This CL system has good precision with a relative standard deviation of 1.9%in eleven repeated measurement of 100.0 pmol/L solution of cobalt（Ⅱ）ion.This work not only discovers a new CL property of BP QDs,but also develops a powerful tool for monitoring cobalt（Ⅱ）ion in silica gel and rain water samples.Part two.Determination of α-glucosidase by chemiluminescence analysis based on a novel Ag@BP QDs nanomaterialsThe chemical functionalized Ag@BP QDs,with the shape of "core-shell",were prepared by mechanical stirring and solvothermal strategy.By reducing Ag+,silver nanoparticles can be generated around the BP QDs to form a "core-shell" Ag@BP QDs,which enhanced the stability and catalytic activity of Ag@BP QDs.The CL signal of the system was reduced since ascorbic acid（AA）was released with the specific hydrolysis of 2-O-α-D-glucopyranosyl-L-ascorbic acid（AGG）by αlpha-glucosidase.Therefore,Ag@BP QDs-luminol CL system was established for sensitive and rapid determination of α-Glu activity.There was a good linear relationship between the inhibition rate and α-Glu concentration in the range of 0.05～2.00 U/mL,with the detection limit was 0.024 U/mL.The relative standard deviations was 2.6%（0.25 U/mL,n=11）.This method has been successfully applied to the determination and screening of inhibitor.In summary,the water-soluble BP QDs and Ag@Bp QDs were successfully prepared by solvothermal method.CL analysis methods were established for detection Co（Ⅱ）and alpha-glycosidase based on the excellent optical properties and catalytic activities of both materials.These CL methods have become powerful analytical techniques due to its superior advantages such as no background light interference,rapidity,low cost,high sensitivity and good selectivity.At the same time,they have successfully realized the detection of Co（Ⅱ）in silica gel and rain water,and alphaglycosidase inhibitor screening.This thesis not only expands the research of BP QDs in the field of chemiluminescence,but also has important significance for environmental monitoring and diagnosis of diabetes.