Three Cyclodextrin Functionalized Graphenes For Detection Of Molecules And Ions

BackgroundGraphene(rGO)has been widely used in the fields of chemistry,biology,materials,and other fields because of its large specific surface area,good toughness and strength,and superior electrical and thermal conductivity.Graphene has a large ?-conjugation system,which can adsorb fluorescing substances with aromatic structure through ?-? conjugate stacking action,and generate fluorescence resonance transition to generate fluorescence quenching phenomenon,but the analytical method based on ?-? conjugate stacking action is poorly selective.Therefore,we designed and prepared a variety of cyclodextrin(CD)-graphene sensors,then detection and identification of betaxolol hydrochloride based on competitive inclusion reaction between cyclodextrin and fluorescent dyes and analytes.Then,we studied the detection and identification of amantadine hydrochloride without ?-conjugated system by a variety of cyclodextrin-graphene sensors.At the same time,we found that R6G/?-CD@rGO and R6G/?-CD@rGO can detect calcium and magnesium ions.Objective(1)Three kinds of fluorescence sensors were prepared by preparing R6G/ alpha-CD@rGO,R6G/ beta-CD@rGO and R6G/ gamma-CD@rGO to realize the detection of betaxolol hydrochloride;(2)Preparation of R6G/?-CD@rGO,R6G/?-CD@rGO and R6G/?-CD@rGO fluorescence sensors for the detection of amantadine hydrochloride.(3)Detection of calcium and magnesium ions was achieved by the fluorescence sensors of preparing R6G/?-CD@r GO and R6G/?-CD@rGO.Method(1)GO forms FD/GO complexes by ?-? stacking interaction with fluorescence dyes(FD),and fluorescence quenching occurs by resonance energy transfer.Due to the competition package cooperation between the fluorescent dye or the analyte(betaxol hydrochloride and amantadine hydrochloride)and cyclodextrin,when the package cooperation intensity of the fluorescent dye and cyclodextrin is weaker than the package cooperation strength of betaxolol hydrochloride and cyclodextrin,the fluorescent dye can be replaced by betaxolol hydrochloride and showed fluorescence and achieved the phenomenon of fluorescence "on-off",(2)The functionalized graphenes(R6G/?-CD@rGO,R6G/?-CD@rGO and R6G/?-CD@rGO)were characterized by TEM?UV-vis and TGA.After addition of R6 G to R6G/?-CD@rGO,R6G/?-CD@rGO and R6G/?-CD@rGO dispersion,the fluorescence of the system will be quenched.After the addition of betaxolol hydrochloride or amantadine hydrochloride,the competition between ?-CD@rGO,?-CD@rGO and ?-CD@rGO and R6 G and betaxolol hydrochloride or amantadine hydrochloride,the fluorescent molecules were displaced to show fluorescence,and fluorescence recovery rate was measured to achieve the purpose of detection.Result(1)The characterization results showed that ?-CD,?-CD and ?-CD were successfully modified on graphene.The R6G/?-CD@rGO,R6G/?-CD@rGO and R6G/?-CD@rGO fluorescence sensors can quickly and sensitively detect the betaxolol hydrochloride content.(2)The R6G/?-CD@rGO,R6G/?-CD@rGO and R6G/?-CD@rGO fluorescence sensors can quickly and sensitively detect betaxolol hydrochloride.(3)The R6G/?-CD@rGO and R6G/?-CD@rGO fluorescence sensors can quickly and sensitively detect calcium and magnesium ions.Conclusion(1)The R6G/?-CD@rGO,R6G/?-CD@rGO,and R6G/?-CD@rGO fluorescence sensors exhibited a good linear relationship when measured at a concentration of 0.0500-16.0000 ?mol/L in betaxolol hydrochloride.The sensor of R6G/?-CD@rGO has the lowest detection sensibility to betaxolol hydrochloride.(2)The R6G/?-CD@rGO,R6G/?-CD@rGO and R6G/?-CD@rGO fluorescence sensors exhibit a good linear relationship when the amantadine hydrochloride concentration of 0.1000-0.8000 mmol/L.The sensor of R6G/?-CD@rGO has the lowest sensibility to amantadine hydrochloride detection.(3)The R6G/?-CD@rGO and R6G/?-CD@rGO fluorescence sensors have a good linear relationship with the detection of Ca2+ at concentrations of 0.3000-1.0000 ?mol/L,R6G/?-CD@rGO and R6 G.The ?-CD@rGO fluorescence sensor showed a good linear relationship at the concentration of 0.2000-1.2500 ?mol/L for magnesium ion detection.