Synthesis,Chemiluminescence And Application Of Catalyst Metal Ion And Luminescent Reagents Bifunctionalized 2D Nanomaterials

In this dissertation,the concept and principle as well as typical reactions and catalysts of chemiluminescence?CL?and CL analysis were introduced and the state of arts on the development of CL functionalized nanomaterials were reviewed.Recently,the concept of nanomaterials bifunctionalized by both catalyst and CL reagent have been proposed.The bifunctionalized nanomaterials not only maintain the excellent properties derived from the nanomaterials,but also exhibit unique CL properties,thus rendering them great application potentials in clinical diagnosis,drug analysis,environmental monitoring and food safety,etc.However,the bifunctionalized nanomaterials are far from fully developed.They still cannot meet the requirements for ultra-trace detection and CL microimaging.Two-dimensional nanomaterials with layered structure at nanoscale usually have special physical and chemical properties.They can be endowed with novel properties and functions via surface modification or functionalization,and thus possessing wide applications in many fields.The aim of this dissertation is to develop novel bifunctionalized 2D nanomaterials with metal ion catalyst and CL reagent,to investigate their properties and to explore their applications.By virtue of coordination,?-? interaction,electrostatic interaction and specific chemical reactions,the CL reagent and metal ion catalyst can be functional ized on the surface of 2D nanomaterials.In this dissertation,four novel bifunctionalized nanomaterials were developed.The morphology and surface composition of those materials were characterized,and their assembly mechanisms were discussed.Their CL properties and CL mechanisms were studied.Based on those bifunctionalized nanomaterials,a series of analytical methods were developed,including a sensitive,selective,reagent-less and disposable CL sensor for the detection of ascorbic acid;a CL sensor for detection of thioglycolic acid base on time-resolved kinetics;and a smartphone CL imaging method for rapid detection of hydrogen peroxide.The main results are as follows:1.Lucigenin?Luc?and Co²⁺ complex bifunctionalized graphene oxide?Co?Trp?2/Luc/GO?was synthesized via a facile and simple strategy by virtue of ?-? stacking and electrostatic interaction.The as-prepared Co?Trp?2/Luc/GO hybrids exhibited good stability,water-solubility and excellent CL activity when reacted with H2O2.The CL intensity of the Co?Trp?2/Luc/GO hybrids was more than 30 times higher than that of lucigenin functionalized GO?Luc/GO?.The CL mechanism between Co?Trp?2/Luc/GO and H2O2 has been proposed to be due to that Co²⁺ could facilitate the formation of HO·,O2·-and Co²⁺-HO2-,accelerating lucigenin CL reaction.Moreover,it was also found that ascorbic acid could directly react with Co?Trp?2/Luc/GO to generate CL emission in the presence of the dissolved oxygen.By virtue of Co?Trp?2/Luc/GO as a platform,a sensitive,selective,reagent-less and disposable CL sensor for the detection of ascorbic acid was developed.Ascorbic acid could be determined in the range of 5.0×10-7-1.0×10-3 M with a detection limit of 0.4?M.This work reveals that catalyst Co?Trp?2 assembled on the surface of Luc/GO exhibits unique catalytic effect on lucigenin CL reaction,which provides a new strategy for the synthesis of lucigenin functionalized nanomaterial with high CL efficiency.The synthesized Co?Trp?2/Luc/GO may find more applications in the development of analytical methods.2.GO-based hybrids consisting of N-?4-Aminobutyl?-N-ethylisoluminol?ABEI?,cobalt???-8-hydroxyquinoline-5-sulfonic acid complex?Co??HQS?2?and reduced GO hybrids?Co??HQS?2/ABEI/rGO?were successful synthesized via a facile strategy by virtue of ?-? stacking and coordination.The as-prepared Co??HQS?2/ABEI/rGO hybrids had good stability and can be easily purified.Co??HQS?2/ABEI/rGO could be used as an excellent nanocatalytic reaction platform for CL when reacted with hydrogen peroxide,the dissolved oxygen and periodate in alkaline solution.And the CL intensity was 80,500 and 150 times higher than the previously reported ABEI/GO,respectively.This was attributed to that Co??HQS?2 catalyzed the generation of reactive radicals such as HO·,O2·-,periodate anion radicals?I??and ?-conjugated carbon radicals??-C=C·?as well as ABEI·-on GO surface.GO as a reaction platform facilitated the reaction of ABEI·-with O2·-to produce intensive CL.It was also found that dilution-initiated CL enhancement in Co??HQS?2/ABEI/rGO-H2O2 system,but not in Co??HQS?2/ABEI/rGO-O2 and Co??HQS?2/ABEI/rGO-KIO4 systems.This was due to the competition of dilution-decreased reduced GO quenching effect and dilution-decreased Co??HQS?2 concentration.This work provides new insight into physicochemical property of functionalized GO hybrids and excellent nanocatalytic platforms for CL reactions,which may find future applications in bioassays,biosensors,bioimaging and microchips.3.Bifunctionalized graphene quantum dots with the catalyst Cu²⁺ and CL reagent ABEI(Cu²⁺/ABEI@GQDs)were developed.ABEI and Cu²⁺ were modified to the surface of GQDs by amidation reaction,electrostatic interaction and coordination.Cu²⁺/ABEI@GQDs exhibits excellent CL properties under both alkaline and weakly alkaline conditions when reacted with H2O2,which is superior to the previously reported ABEI functionalized GQDs.The CL intensity of Cu²⁺/ABEI@GQDs is more than 2 orders of magnitude than that of ABEI@GQDs.In Cu²⁺/ABEI@GQDs-H2O2 CL system,Cu²⁺ can catalyze the decomposition of hydrogen peroxide to produce active oxygen-containing radicals and GQDs can promote production of free radical and electron transfer.Based on the synergistic catalyst effect of GQDs and Cu²⁺,the CL intensity and duration are significantly improved.In addition,in the presence of sulfhydryl compounds,Cu²⁺ ions can be reduced to Cu+ by sulfhydryl group.The Cu+produced by this reaction preferred to coordinate with the excess of sulfhydryl compounds and forms?RS-Cu??complexes.It will inhibit the cyclic catalytic decomposition of hydrogen peroxide between Cu²⁺-Cu+,resulting in the quenching of CL.With the consumption of sulfhydryl compounds,the CL signal can be gradually recovered.Then,using thioglycolic acid?TGA?as a model target,we developed a CL sensor for detection of sulfhydryl group based on the time-resolved kinetics.This detection strategy opens up a new way to design novel CL assays.4.A novel CL functionalized nanoclay hydrogel(Co²⁺/Lum-LAP)was developed.CL reagent luminol was adsorbed to the surface of the 2D layered nanoclay laponite?LAP?by hydrogen bonding,electrostatic interaction and ?-? interactions.Subsequently,Co²⁺ as a cation exchanger was modified to LAP through ion exchange reaction,under the synergistic effect of electrostatic attraction and osmotic pressure.Finally,the LAP was self-assembled into a "card house" structure to form hydrogel.In the Co²⁺/Lum-LAP hydrogel-H2O2 system,the hydrogel has excellent CL properties.The light emission is visible by naked eyes and can last for over an hour.Co²⁺ can catalyze the decomposition of H2O2 to produce active radicals,resulting in a strong CL emission.LAP forms a tight layered "card house" structure in the gel,which reduces the diffusion rate of H2O2,resulting in long-term glow CL emission.The immobilization of Co²⁺ on nanoclay enhances the catalytic activity and stability of Co²⁺.Therefore,the Co²⁺/Lum-LAP hydrogel can produce strong CL emission under weak acidic and neutral conditions.By virtue of smartphone,a rapid and simple CL imaging method for determining H2O2 was successfully developed.Based on those advantages,Co²⁺/Lum-LAP hydrogel has great application potential in biosensors,microchips and bioimaging.