A kind of multifunctional and composite type nanometer ratio fluorescent chemical sensor and preparation method thereof andUsingTechnical field
The invention belongs to technical field of environment function material preparation, specifically a kind of mercury ion that is suitable for simultaneously is examinedIt surveys, the preparation method of absorption and the multifunctional and composite type nanometer ratio fluorescent chemical sensor removed,
Background technique
Hypertoxicity, persistence, property easy to migrate and height bioconcentration make mercury ion become currently to natural environment andOne of the environmental contaminants that human health most endangers.Accurate detection, quick adsorption and effective removal of mercury ion are for environment, lifeObject medicine and industrial and agricultural production etc. all have very important significance.
Mercury ion detecting based on fluorescence chemical sensor can provide a kind of fast and convenient real-time in-situ analysis method, butTo be with single luminous intensity variations be detect signal fluorescence chemical sensor it is dense vulnerable to exciting power, probe in actually sensingThe influence of the factors variation such as degree and experimental situation, to influence the accuracy and precision of detection to a certain extent.With reference listThe ratio of fluorescence intensity change carrys out the ratio fluorescent sensor of quantitative detection object at member and two wavelength of fluorescence of detection unit,Due to the introducing of reference cell, measurement error caused by equipment condition itself and external environmental interference can be effectively reduced.At presentMolecule-type ratio fluorescent sensor synthetic route based on organic molecule building is more complex, can not be recycled, it is also difficult to realizeSeparation removes mercury ion from system, is unfavorable for commercially producing application on a large scale.
In recent years, there is research work by the different function monomer with reference and detection property with covalent bond, embedding, oversubscriptionThe forms such as subgroup dress, which are incorporated into, forms compound nanometer ratio fluorescent chemical sensor in the host material with nanostructure.This not only can simplify complicated MOLECULE DESIGN synthesis, while be beneficial to functional further expansion.As a kind of importantFunctional form nano material, magnetic mesoporous Nano particles of silicon dioxide have unique magnetic responsiveness, orderly adjustable meso-hole structure,Big specific surface area is easy to the features such as chemical modification, hypotoxicity, good biocompatibility and stability, while its synthetic methodSimply, easily modification is suitable for practical application and expanded production convenient for separating and recovering and reusing by externally-applied magnetic field.QuantumPoint has wide excitation spectrum and narrow emission spectra, and biggish Stokes shift, photochemical stability is high, and fluorescence lifetime length etc. is excellentFluorescent characteristic more is a kind of ideal fluorescence reference cell functive；It is induced using rhodamine Spirocyclic derivatives in objectThe switch of loop coil can occur down and cause the change of fluorescence signal to construct the research hotspot that fluorescence probe is always sensory field.However, there are no receive magnetic mesoporous silica in the research of current existing all kinds of compound ratio fluorescent sensorsRice corpuscles, quantum dot and rhodamine Spirocyclic derivatives be combined together preparation can be achieved at the same time mercury ion detecting, absorption andThe report of the multifunctional and composite type nanometer ratio fluorescent chemical sensor of removal.
Summary of the invention
The invention aims to provide a kind of multifunctional and composite type nanometer ratio fluorescent chemical sensor and its preparation sideMethod, the chemical sensor are suitable for mercury ion detecting, absorption and removal simultaneously.
The technical scheme is that
Multifunctional and composite type nanometer ratio fluorescent chemical sensor, chemical expression are as follows: Fe3O4@SiO2/CdTe/SiO2@mSiO2-Rh6G。
Multifunctional and composite type nanometer ratio fluorescent chemical sensor preparation method carries out as steps described below:
(1) monodispersed four oxidations three-body nanoparticle (Fe is prepared using hydro-thermal method3O4)；
(2) the ferriferrous oxide nano grain of the non-porous silicas cladding of surface amination is prepared using sol-gel methodSon (Fe3O4@SiO2-NH2)；
(3) magnetism two of rubescent color fluorescence CdTe quantum dot is embedded using EDC/NHS coupling method and sol-gel method preparationSilicon oxide nanoparticle (Fe3O4@SiO2/CdTe/SiO2)；
(4) the magnetic mesoporous silica of rubescent color fluorescence CdTe quantum dot is embedded using surfactants' templating preparationNanoparticle (Fe3O4@SiO2/CdTe/SiO2@mSiO2)；
(5) embedding is modified by the method for covalent coupling using the rhodamine Spirocyclic derivatives to the sensitive green light of mercury ionThe magnetic mesoporous Nano particles of silicon dioxide of cadmium telluride quantum dot prepares multifunctional and composite type nanometer ratio fluorescent chemical sensor(Fe3O4@SiO2/CdTe/SiO2@mSiO2-Rh6G)。
The beneficial effects of the present invention are:
There is presently no magnetic mesoporous Nano particles of silicon dioxide, quantum dot and rhodamine Spirocyclic derivatives are assembled into listThe correlative study that multifunctional and composite type ratio fluorescent sensor is prepared in one nanostructure utilizes magnetic mesoporous silica nanometerOn the one hand this technical solution that signal reference cell and detection unit combine can be greatly simplified traditional ratio by particleThe Molecular Design and synthetic route of rate fluorescent optical sensor complexity, only need to be by replacing different signal reference and signal detectionUnit can be achieved with the testing requirements to different target object；On the other hand the introducing of magnetic mesoporous Nano particles of silicon dioxide can be withRealize the multifunction of sensor, can either quick and precisely quantitative detection ion concentration of mercury, while can also be by being modified with detectionAbsorption, removal and reuse of the simple and efficient realization of the mesoporous layer and externally-applied magnetic field of unit to mercury ion；Secondly, the systemQuantum dot is embedded in the nonporous silica silicon layer between magnetic core and the mesoporous layer for modifying detection unit in Preparation Method, due toThe protection of transparent inert silicon dioxide layer make its as reference signal photoluminescent property substantially not by magnetic kernel and other outsideCarry out the interference of factor；Equipment condition itself and extraneous ring can be effectively reduced using this ratio fluorescent sensor measurement mercury ionMeasurement error caused by border is interfered, improves the accuracy and accuracy of testing result.
Detailed description of the invention
Fig. 1 is Fe3O4(A)；Fe3O4@SiO2-NH2(B)；Fe3O4@SiO2/CdTe(C)；Fe3O4@SiO2/CdTe/SiO2(D)；Fe3O4@SiO2/CdTe/SiO2@mSiO2(E, F) projects Electronic Speculum (TEM) figure and Fe3O4@SiO2/CdTe/SiO2@mSiO2(F)；Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G (G) scanning electron microscope (SEM) figure.
Fig. 2 is Fe3O4(a)；Fe3O4@SiO2/CdTe/SiO2@mSiO2(b)；
Fe3O4@SiO2/CdTe/SiO2@mSiO2The X-ray powder diffraction (XRD) of-Rh6G (c)；
Fig. 3 is Fe3O4@SiO2/CdTe/SiO2@mSiO2The small angle XRD of-Rh6G；
Fig. 4 is Fe3O4@SiO2/CdTe/SiO2@mSiO2-Rh6G N2Adsorption-desorption isothermal；
Fig. 5 is Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G Rich Internet Applications under hysteresis loop and externally-applied magnetic field at room temperatureSchematic diagram.
Fig. 6 is Fe3O4@SiO2/CdTe/SiO2@mSiO2Various concentration Hg is added in-Rh6G (20mg/mL)2+Fluorescence spectrumFigure.
Fig. 7 is Fe3O4@SiO2/CdTe/SiO2@mSiO2The variation of-Rh6G (20mg/mL) ratio fluorescent intensity and Hg2+It is denseRelation curve between degree.
Fig. 8 is Fe3O4@SiO2/CdTe/SiO2@mSiO2When-Rh6G (20mg/mL) is to various interfering ion individualisms withAnd selective response curve when being coexisted with mercury ion.
Fig. 9 is Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G (20mg/mL) reusable linearity curve.
Figure 10 is the time to Fe3O4@SiO2/CdTe/SiO2@mSiO2The influence of-Rh6G absorption mercury ion.
Specific embodiment
For defect recited above, applicants have invented a kind of multifunctional and composite type nanometer ratio fluorescent chemical sensitisationsDevice.
Technical solution of the present invention and application are further described below with reference to embodiment, as described below is only the present inventionPreferred embodiment, be not intended to limit the scope of the present invention.
The technical solution adopted by the present invention is that using magnetic mesoporous Nano particles of silicon dioxide as host material by signalThe rhodamine loop coil of the CdTe quantum and detecting signal unit of reference cell hair the red fluorescence green light sensitive to mercury ionDerivative is fitted together by embedding and the method covalently grafted, and formation is reusable, is capable of providing more acurrate detection knotFruit simultaneously can quick adsorption and effective multifunctional and composite type nanometer ratio fluorescent chemical sensor for removing mercury ion.
Embodiment 1
(1) monodispersed ferriferrous oxide nano-particle (Fe is prepared3O4): 1.35g ferric chloride hexahydrate, 3.6g is anhydrousSodium acetate and 1g sodium citrate are dissolved in 40mL ethylene glycol, and mixed solution obtains uniform Huang after being vigorously mixed at room temperature for 15minThe reaction precursor liquid solution of color；50ml is transferred into 200 DEG C of reactions in the stainless steel cauldron of polytetrafluoroethyllining liningFor 24 hours, it is washed respectively 3 times after cooled to room temperature with ethyl alcohol and deionized water, 60 DEG C of vacuum drying obtain black Fe for 24 hours3O4It receivesRice corpuscles.Product Fe3O4TEM, XRD and hysteresis loop as shown in Figure 1A, 2,5.
(2) ferriferrous oxide nano-particle (Fe of the non-porous silicas cladding of surface amination is prepared3O4@SiO2-NH2): by 0.05g Fe3O4Nanoparticle with 20mL EtOH Sonicate handle after be dispersed in containing 20mL ethyl alcohol, 10mL go fromIt in the mixed solution of sub- water and 0.5mL ammonium hydroxide, is vigorously stirred down and 0.03g TEOS is added dropwise, be added after reacting at room temperature 6hThe reaction was continued is centrifuged afterwards for 24 hours by 0.2mL APS, is respectively washed three times with ethyl alcohol and deionized water, 60 DEG C of vacuum drying obtain surface for 24 hoursRich in amino Fe3O4@SiO2, the TEM of product is as shown in Figure 1B.
(3) the magnetic silica nanoparticle (Fe of preparation embedding hair red fluorescence cadmium telluride quantum dot3O4@SiO2/CdTe/SiO2): by the Fe of 0.05g surface amination3O4@SiO2Ultrasonic disperse surpasses to 2mL redistilled water, then by 2mL CdTe QDsSound is distributed to sodium dihydrogen phosphate-disodium hydrogen phosphate buffering of 20mL 1- ethyl -3- (3- dimethylaminopropyl) carbodiimide hydrochlorideThen two solution are uniformly mixed under ultrasonication, are protected from light 8h at room temperature, obtain product by solution (pH=5)Fe3O4@SiO2/ CdTe, as shown in Figure 1 C；By Fe3O4@SiO2After/CdTe centrifuge washing ultrasonic disperse containing 20mL ethyl alcohol,It in the mixed solution of 10mL deionized water and 0.5mL ammonium hydroxide, is vigorously stirred down and 0.03g TEOS is added dropwise, after reacting at room temperature 6hSiO is formed on quantum dot surface2Protective layer is respectively washed three times with ethyl alcohol and deionized water, and 60 DEG C of vacuum drying obtain for 24 hoursFe3O4@SiO2/CdTe/SiO2, the TEM of product is as shown in figure iD.
(4) the magnetic mesoporous Nano particles of silicon dioxide (Fe of preparation embedding hair red fluorescence cadmium telluride quantum dot3O4@SiO2/CdTe/SiO2@mSiO2): by 0.05g Fe3O4@SiO2/CdTe/SiO2Ultrasonic disperse to contain 0.15g CTAB, 30mLIn the mixed solution of ethyl alcohol, 40mL deionized water and 0.6mL ammonium hydroxide, 0.2g TEOS is added dropwise after being vigorously stirred, reacts at room temperature6h is respectively washed three times with ethyl alcohol and deionized water, after being repeated twice in 200mL ethanol-hydrogen chloride solution back flow reaction 48h, 80DEG C vacuum drying 48h obtain Fe3O4@SiO2/CdTe/SiO2@mSiO2, TEM, SEM, XRD, small angle XRD, N of product2Absorption-is de-Attached thermoisopleth is as shown in Fig. 1 E-G, 2,3,4.
(5) multifunctional and composite type nanometer ratio fluorescent chemical sensor (Fe is prepared3O4@SiO2/CdTe/SiO2@mSiO2-Rh6G): 0.44g Rh6G being dissolved in 20mL anhydrous tetrahydro furan, the excessive APS of 2mL is added dropwise under stirring, nitrogen is protectedMost of solvent is boiled off after protecting lower back flow reaction 48h, a large amount of cold normal hexanes are added, is centrifuged after white powder precipitating is precipitated, use is coldN-hexane wash repeatedly repeatedly, obtain Rh6G-Si after 60 DEG C of vacuum drying 8h；Then by 0.1gRh6G-Si and 0.1gFe3O4@SiO2/CdTe/SiO2@mSiO2(in 150 DEG C of vacuum activatings 24 hours) is added in the dry toluene of 50mL, and nitrogen protection is next timeStream reaction 48 hours, is centrifuged, after successively respectively being washed three times with toluene, ethyl alcohol, ether, 60 DEG C of vacuum drying be can be obtained after coolingFe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G, SEM, XRD of product, hysteresis loop are as shown in Fig. 1 H, 2,5.
(6) detection of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: taking 12 sample bottles, respectivelyThe Fe that 2mg is prepared by step (1)~(5) is added3O4@SiO2/CdTe/SiO2@mSiO2Then-Rh6G has respectively matched 100mLThe mercury ion standard HEPES that the concentration made is 0,0.7,1.6,2.5,3.2,4.1,5,5.8,6.5,7.2,8.2,9.0nM is moltenLiquid (pH=7) is added in 12 sample bottles, room temperature ultrasound 3~5 minutes, stands 2 minutes.Respectively measure 2mL sample dispersion liquid inIn cuvette, using the fluorescence intensity of sepectrophotofluorometer test sample, the fluorescence emission spectrum variation of 12 samples is obtainedFigure, as shown in Figure 6.According to Stern-Volmer establishing equation ratio fluorescent intensity-concentration standard curve, as shown in Figure 7.
(7) 13 samples detecting and selecting property of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: are takenBottle, is separately added into the Fe that 2mg is prepared by step (1)~(5)3O4@SiO2/CdTe/Si02@mSiO2Then-Rh6G respectively willThe 100mL competition that prepared concentration has been 1.0mM identifies ion K+、Na+、Al3+、Ca2+、Mg2+、Mn2+、Ni2+、pb2+、Zn2+、Ag+、Co2+、Cr2+、Cu2+HEPES solution (pH=7) be added 12 sample bottles in, room temperature ultrasound 3~5 minutes, stand 2 pointsClock.2mL sample dispersion liquid is measured respectively in cuvette, using the ratio fluorescent intensity of sepectrophotofluorometer test sample,It then proceedes to that the mercury ion standard HEPES solution that 0.1mL concentration is 1 μM is added, ultrasound 3~5 minutes stands 2 minutes, recyclesThe ratio fluorescent intensity of sepectrophotofluorometer test sample.Fe3O4@SiO2/CdTe/SiO2@mSiO2The selectivity of-Rh6G is such asShown in Fig. 8.
(8) reusability of multifunctional and composite type nanometer ratio fluorescent chemical sensor: in sample bottle be added 2mg byThe Fe of step (1)~(5) preparation3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G, then by 100mL, prepared concentration is 1 μThe mercury ion standard solution of M is added in sample, room temperature ultrasound 3~5 minutes, stands 2 minutes.2mL sample dispersion liquid is measured respectivelyIn cuvette, using the fluorescence intensity of sepectrophotofluorometer test sample, later with magnet by Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G is separated, and in the KI solution that ultrasonic disperse to 2mL concentration is 100 μM, recycles fluorescence spectrophotometryThe fluorescence intensity for counting test sample carries out loop test by aforesaid operations.Fe3O4@SiO2/CdTe/SiO2@mSiO2The weight of-Rh6GMultiple practicability is as shown in Figure 9.
(9) absorption and removal performance of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: 5mg is weighedThe Fe prepared by step (1)~(5)3O4@SiO2/CdTe/SiO2@mSiO2The concentration that the has prepared of-Rh6G ultrasonic disperse to 10mLFor 20mgL-1Mercury ion solution in (pH=7), shaken at room temperature with constant rate machinery, when certain absorptionBetween, with magnet by Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G is separated, and takes supernatant, measures solution using ICP/AESIn remaining ion concentration of mercury.It is calculated using the following equation Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G adsorbs t to mercury ionAdsorbance, absorption when the time reach equilibrium adsorption capacity and removal rate when balancing:
T time adsorbance:
Equilibrium adsorption capacity:
Wherein in formula, C0(mg·L-1) be mercury ion initial concentration, Ct(mg·L-1) and Ce (mgL-1) it is when adsorbing tBetween and adsorption equilibrium after in solution mercury ion residual concentration, V (L) is the volume of solution, and M (g) is Fe3O4@SiO2/CdTe/SiO2@mSiO2The quality of-Rh6G.Time is to Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G adsorbs the influence of mercury ion as schemedShown in 10.
Embodiment 2
(1) monodispersed Fe is prepared3O4Nanoparticle: by 2.7g ferric chloride hexahydrate, 7.2g anhydrous sodium acetate and 1g lemonSour sodium is dissolved in 40mL ethylene glycol, and mixed solution obtains the precursors of homogeneous yellow after being vigorously mixed at room temperature for 30minSolution；100ml is transferred into 160 DEG C of reaction 12h in the stainless steel cauldron of polytetrafluoroethyllining lining, is naturally cooled toIt is washed respectively 3 times after room temperature with ethyl alcohol and deionized water, 60 DEG C of vacuum drying 12h obtain black Fe3O4Nanoparticle.
(2) Fe of surface amination is prepared3O4@SiO2: by 0.1g Fe3O4After nanoparticle is handled with 20mL EtOH SonicateIt is dispersed in the mixed solution containing 20mL ethyl alcohol, 10mL deionized water and 0.5mL ammonium hydroxide, is vigorously stirred down and is added dropwise0.06g TEOS is reacted at room temperature and 0.4mLAPS is added after 6h the reaction was continued is centrifuged afterwards for 24 hours, washed with ethyl alcohol and deionized water and respectively washedIt washs three times, 60 DEG C of vacuum drying obtain surface rich in amino Fe for 24 hours3O4@SiO2。
(3) Fe is prepared3O4@SiO2/CdTe/SiO2: by the Fe of 0.1g surface amination3O4@SiO2Ultrasonic disperse is heavy to 2mLWater is steamed, then by 2mL CdTe QDs ultrasonic disperse to the phosphorus of 20mL 1- ethyl -3- (3- dimethylaminopropyl) carbodiimide hydrochlorideAcid dihydride sodium-disodium hydrogen phosphate buffer solution (pH=6) then will uniformly mix, at room temperature under two solution ultrasonicationsIt is protected from light 12h, obtains product Fe3O4@SiO2/CdTe；By Fe3O4@SiO2Ultrasonic disperse is containing after/CdTe centrifuge washingIn the mixed solution of 20mL ethyl alcohol, 10mL deionized water and 0.5mL ammonium hydroxide, it is vigorously stirred down and 0.06g TEOS, room is added dropwiseSiO is formed on quantum dot surface after temperature reaction 6h2Protective layer is respectively washed three times with ethyl alcohol and deionized water, and 60 DEG C of vacuum are dryIt is dry to obtain Fe for 24 hours3O4@SiO2/CdTe/SiO2。
(4) Fe is prepared3O4@SiO2/CdTe/SiO2@mSiO2: by 0.1g Fe3O4@SiO2/CdTe/SiO2Ultrasonic disperse arrivesIn mixed solution containing 0.15g CTAB, 30mL ethyl alcohol, 40mL deionized water and 0.6mL ammonium hydroxide, add dropwise after being vigorously stirredEnter 0.4g TEOS, reacts at room temperature 6h, respectively washed three times with ethyl alcohol and deionized water, after being repeated twice, in 200mL ethanol-hydrogen chlorideBack flow reaction 48h in solution, 80 DEG C of vacuum drying obtain Fe for 24 hours3O4@SiO2/CdTe/SiO2@mSiO2
(5) Fe is prepared3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G: 0.8g Rh6G is dissolved in the anhydrous tetrahydro furan of 20mLThe APS of 4mL is added dropwise in muttering, under stirring, boils off most of solvent under nitrogen protection after back flow reaction 48h, is added a large amount of coldN-hexane, be centrifuged after white powder precipitating is precipitated, wash repeatedly with cold n-hexane multiple, 60 DEG C of vacuum drying obtain afterwards for 24 hoursRh6G-Si；Then by 0.5g Rh6G-Si and 0.5gFe3O4@SiO2/CdTe/SiO2@mSiO2It is (small in 150 DEG C of vacuum activatings 24When) be added in the dry toluene of 100mL, back flow reaction 48 hours under nitrogen protection are centrifuged after cooling, successively use toluene, secondAfter alcohol, ether respectively wash three times, Fe is can be obtained in 60 DEG C of vacuum drying3O4@SiO2/CdTe/SiO2@mSiO2-Rh6G。
(6) detection of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: taking 12 sample bottles, respectivelyThe Fe that 4mg is prepared by step (1)~(5) is added3O4@SiO2/CdTe/SiO2@mSiO2Then-Rh6G has respectively matched 100mLThe mercury ion standard HEPES that the concentration made is 0,0.7,1.6,2.5,3.2,4.1,5,5.8,6.5,7.2,8.2,9.0nM is moltenLiquid (pH=7) is added in 12 sample bottles, room temperature ultrasound 3~5 minutes, stands 2 minutes.Respectively measure 2mL sample dispersion liquid inIt is glimmering according to Stern-Volmer establishing equation ratio using the fluorescence intensity of sepectrophotofluorometer test sample in cuvetteLuminous intensity-concentration standard curve.
(7) 13 samples detecting and selecting property of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: are takenBottle, is separately added into the Fe that 4mg is prepared by step (1)~(5)3O4@SiO2/CdTe/SiO2@mSiO2Then-Rh6G respectively willThe 100mL competition that prepared concentration has been 1.0mM identifies ion K+、Na+、Al3+、Ca2+、Mg2+、Mn2+、Ni2+、pb2+、Zn2+、Ag+、Co2+、Cr2+、Cu2+HEPES solution (pH=7) be added 12 sample bottles in, room temperature ultrasound 3~5 minutes, stand 2 pointsClock.2mL sample dispersion liquid is measured respectively in cuvette, using the ratio fluorescent intensity of sepectrophotofluorometer test sample,It then proceedes to that the mercury ion standard HEPES solution that 0.1mL concentration is 1 μM is added, ultrasound 3~5 minutes stands 2 minutes, recyclesThe ratio fluorescent intensity of sepectrophotofluorometer test sample.
(8) reusability of multifunctional and composite type nanometer ratio fluorescent chemical sensor: in sample bottle be added 4mg byThe Fe of step (1)~(5) preparation3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G, then by 100mL, prepared concentration is 1 μThe mercury ion standard solution of M is added in sample, room temperature ultrasound 3~5 minutes, stands 2 minutes.2mL sample dispersion liquid is measured respectivelyIn cuvette, using the fluorescence intensity of sepectrophotofluorometer test sample, later with magnet by Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G is separated, and in the KI solution that ultrasonic disperse to 2mL concentration is 100 μM, recycles fluorescence spectrophotometryThe fluorescence intensity of test sample is counted, circulation aforesaid operations carry out reusability test.
(9) it absorption and removal performance of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: weighsThe Fe that 10mg is prepared by step (1)~(5)3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G ultrasonic disperse has been prepared to 10mL'sConcentration is 40mgL-1Mercury ion solution in (pH=7), shaken at room temperature with constant rate machinery, every certain absorptionTime, with magnet by Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G is separated, and takes supernatant, is measured using ICP/AES moltenRemaining ion concentration of mercury in liquid.Multifunctional and composite type nanometer ratio fluorescent is calculated using the formula in 1 step of embodiment (9)It learns adsorbance when sensor adsorbs the t time to mercury ion, adsorb up to the equilibrium adsorption capacity and removal rate when balancing.
Embodiment 3
(1) monodispersed Fe is prepared3O4Nanoparticle: by 2.7g ferric chloride hexahydrate, 7.2g anhydrous sodium acetate and 1g lemonSour sodium is dissolved in 40mL ethylene glycol, and mixed solution obtains the precursors of homogeneous yellow after being vigorously mixed at room temperature for 30minSolution；100ml is transferred into 180 DEG C of reaction 16h in the stainless steel cauldron of polytetrafluoroethyllining lining, is naturally cooled toIt is washed respectively 3 times after room temperature with ethyl alcohol and deionized water, 60 DEG C of vacuum drying 12h obtain black Fe3O4Nanoparticle.
(2) Fe of surface amination is prepared3O4@SiO2: by 0.08g Fe3O4After nanoparticle is handled with 20mL EtOH SonicateIt is dispersed in the mixed solution containing 20mL ethyl alcohol, 10mL deionized water and 0.5mL ammonium hydroxide, is vigorously stirred down and is added dropwise0.05g TEOS is reacted at room temperature and 0.4mLAPS is added after 6h the reaction was continued is centrifuged afterwards for 24 hours, washed with ethyl alcohol and deionized water and respectively washedIt washs three times, 60 DEG C of vacuum drying obtain surface rich in amino Fe for 24 hours3O4@SiO2。
(3) Fe is prepared3O4@SiO2/CdTe/SiO2: by the Fe of 0.08g surface amination3O4@SiO2Ultrasonic disperse is to 2mLRedistilled water, then by 2mL CdTe QDs ultrasonic disperse to 20mL 1- ethyl -3- (3- dimethylaminopropyl) carbodiimide hydrochlorideSodium dihydrogen phosphate-disodium hydrogen phosphate buffer solution (pH=4) then will uniformly mix under two solution ultrasonications, in room temperatureUnder be protected from light 12h, obtain product Fe3O4@SiO2/CdTe；By Fe3O4@SiO2Ultrasonic disperse is containing after/CdTe centrifuge washingIn the mixed solution of 20mL ethyl alcohol, 10mL deionized water and 0.5mL ammonium hydroxide, it is vigorously stirred down and 0.05g TEOS, room is added dropwiseSiO is formed on quantum dot surface after temperature reaction 6h2Protective layer is respectively washed three times with ethyl alcohol and deionized water, and 60 DEG C of vacuum are dryIt is dry to obtain Fe for 24 hours3O4@SiO2/CdTe/SiO2。
(4) Fe is prepared3O4@SiO2/CdTe/SiO2@mSiO2: by 0.08g Fe3O4@SiO2/CdTe/SiO2Ultrasonic disperse arrivesIn mixed solution containing 0.15g CTAB, 30mL ethyl alcohol, 40mL deionized water and 0.6mL ammonium hydroxide, add dropwise after being vigorously stirredEnter 0.3g TEOS, reacts at room temperature 6h, respectively washed three times with ethyl alcohol and deionized water, after being repeated twice, in 200mL ethanol-hydrogen chlorideBack flow reaction 48h in solution, 80 DEG C of vacuum drying obtain Fe for 24 hours3O4@SiO2/CdTe/SiO2@mSiO2
(5) Fe is prepared3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G: 1g Rh6G is dissolved in 40mL anhydrous tetrahydro furanIn, the APS of 5mL is added dropwise under stirring, boils off most of solvent under nitrogen protection after back flow reaction 48h, is added a large amount of coldN-hexane is centrifuged after white powder precipitating is precipitated, is washed repeatedly with cold n-hexane repeatedly, 60 DEG C of vacuum drying obtain afterwards for 24 hoursRh6G-Si；Then by 1g Rh6G-Si and 1g Fe3O4@SiO2/CdTe/SiO2@mSiO2(in 150 DEG C of vacuum activatings 24 hours)Be added in the dry toluene of 150mL, back flow reaction 48 hours under nitrogen protection are centrifuged after cooling, successively with toluene, ethyl alcohol,After ether respectively washs three times, Fe is can be obtained in 60 DEG C of vacuum drying3O4@SiO2/CdTe/SiO2@mSiO2-Rh6G。
(6) detection of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: taking 12 sample bottles, respectivelyThe Fe that 6mg is prepared by step (1)~(5) is added3O4@SiO2/CdTe/SiO2@mSiO2Then-Rh6G has respectively matched 100mLThe mercury ion standard HEPES that the concentration made is 0,0.7,1.6,2.5,3.2,4.1,5,5.8,6.5,7.2,8.2,9.0nM is moltenLiquid (pH=7) is added in 12 sample bottles, room temperature ultrasound 3~5 minutes, stands 2 minutes.Respectively measure 2mL sample dispersion liquid inIt is glimmering according to Stern-Volmer establishing equation ratio using the fluorescence intensity of sepectrophotofluorometer test sample in cuvetteLuminous intensity-concentration standard curve.
(7) 13 samples detecting and selecting property of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: are takenBottle, is separately added into the Fe that 6mg is prepared by step (1)~(5)3O4@SiO2/CdTe/SiO2@mSiO2Then-Rh6G respectively willThe 100mL competition that prepared concentration has been 1.0mM identifies ion K+、Na+、Al3+、Ca2+、Mg2+、Mn2+、Ni2+、pb2+、Zn2+、Ag+、Co2+、Cr2+、Cu2+HEPES solution (pH=7) be added 12 sample bottles in, room temperature ultrasound 3~5 minutes, stand 2 pointsClock.2mL sample dispersion liquid is measured respectively in cuvette, using the ratio fluorescent intensity of sepectrophotofluorometer test sample,It then proceedes to that the mercury ion standard HEPES solution that 0.1mL concentration is 1 μM is added, ultrasound 3~5 minutes stands 2 minutes, recyclesThe ratio fluorescent intensity of sepectrophotofluorometer test sample.
(8) reusability of multifunctional and composite type nanometer ratio fluorescent chemical sensor: in sample bottle be added 6mg byThe Fe of step (1)~(5) preparation3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G, then by 100mL, prepared concentration is 1 μThe mercury ion standard solution of M is added in sample, room temperature ultrasound 3~5 minutes, stands 2 minutes.2mL sample dispersion liquid is measured respectivelyIn cuvette, using the fluorescence intensity of sepectrophotofluorometer test sample, later with magnet by Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G is separated, and in the KI solution that ultrasonic disperse to 2mL concentration is 100 μM, recycles fluorescence spectrophotometryThe fluorescence intensity of test sample is counted, circulation aforesaid operations carry out reusability test.
(9) it absorption and removal performance of the multifunctional and composite type nanometer ratio fluorescent chemical sensor to mercury ion: weighsThe Fe that 20mg is prepared by step (1)~(5)3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G ultrasonic disperse has been prepared to 10mL'sConcentration is 60mgL-1Mercury ion solution in (pH=7), shaken at room temperature with constant rate machinery, every certain absorptionTime, with magnet by Fe3O4@SiO2/CdTe/SiO2@mSiO2- Rh6G is separated, and takes supernatant, is measured using ICP/AES moltenRemaining ion concentration of mercury in liquid.Multifunctional and composite type nanometer ratio fluorescent is calculated using the formula in 1 step of embodiment (9)It learns adsorbance when sensor adsorbs the t time to mercury ion, adsorb up to the equilibrium adsorption capacity and removal rate when balancing.