CN106353290A - Synthesis method of fluorescent gold nanocluster coated with triazole and lemon yellow detection method - Google Patents

Abstract

The invention provides a synthesis method of a fluorescent gold nanocluster coated with triazole and a lemon yellow detection method. The synthesis method of the fluorescent gold nanocluster coated with triazole comprises the following steps: adding a HAuCl4 aqueous solution into a three-opening flask filled with triple-distilled water; then adding a 3-sulfydryl-1,2,4-triazole aqueous solution under the condition of powerful stirring, reacting for 13 hours at the temperature of 90 DEG C to obtain a colorless solution, calculating the concentration being about 0.11mM according to the Au atomic concentration, and storing the solution in a refrigerator at the temperature of 4 DEG C for later use. Through the synthesis method, a water-soluble fluorescent gold nanocluster (TRO-AuNCs) protected by 3-sulfydryl-1,2,4-triazole (TRO) is synthesized; the gold nano material is combined with the analysis and detection technology; strong and stable fluorescence emission property of TRO-AuNCs is used; TRO-AuNCs is used as a fluorescent molecule; lemon yellow is used as a quenching agent; the fluorescence of the fluorescent molecule TRO-AuNCs is quenched through forster resonance energy transfer between the TRO-AuNCs and the lemon yellow. Based on the above principle, a simple method capable of rapidly detecting lemon yellow in beverage is established.

Description

The fluorescence gold nanoclusters synthetic method of triazole parcel and lemon yellow assay method

Technical field

The invention belongs to field of food, it is related to a kind of fluorescence gold nanoclusters synthetic method of triazole parcel and lemon yellow measures Method.

Background technology

Lemon yellow (tz), its systematic naming method is: 3- carboxyl -5- hydroxyl (P-TOLUENE SULFO ACID 99) -4- (P-TOLUENE SULFO ACID 99's azo)-pyrazoles Trisodium salt, its structural formula is as shown in figure -1.A kind of organic food colour of azo of synthetic, be widely used in baked product, The food industry such as confection and beverage.Recently research display, when the lemon yellow of human body excess intake, may cause to body health Adverse effect, such as asthma, urticaria, chromosome damage, genotoxicity, Behavioral teratogenicity or even cancer.More and more grind Study carefully and also demonstrate that the potential toxicity of lemon yellow.Therefore in food, the content of lemon yellow must obtain strict control.For food Safety and human health, set up a kind of method of quick, sensitive, simple, cheap detection lemon yellow and are extremely necessary.

At present, increasing instrument analytical method has applied to the detection of lemon yellow in food.Main inclusion ultraviolet can See spectrophotography (uv-vis), high performance liquid chromatography (hplc), Capillary Zone Electrophoresis (cze), Electrochemical Detection etc.. But some of which method is because its sample pre-treatments is complicated, time-consuming, sensitivity is low or poor selectivity, be not suitable for conventional inspection Survey.Fluorescence gold nano cluster has the physicochemical characteristicss of uniqueness due to it, as minimum grain size, good bio-compatible Property, good light stability so as to have outstanding performance at aspects such as sensing detection, molecular imaging, the diagnosis of cancer and treatments, and by This plays huge impetus to biomedical and analytical chemistry field scientific research development.And fluorescence sense probe is because letter List, high sensitivity and quick advantage, receive much concern recently.

Content of the invention

The purpose of patent of the present invention is to provide a kind of fluorescence gold nanoclusters synthetic method of triazole parcel and lemon yellow to survey Determine method, gold nano-material is combined with analysis and detection technology, establish a kind of simple, quickly to lemon yellow in beverage Detection method.

The fluorescence gold nanoclusters synthetic method of triazole parcel, adds in the there-necked flask fill 80ml triple distillation water The haucl of 1.0ml, 10mm₄Aqueous solution；Then under conditions of being stirred vigorously, 3- sulfydryl -1 of addition 5.0ml, 10mm, 2,4- Triazole aqueous solution, is 3 about with the ph that the hcl of 1m adjusts solution；React 13 hours under the conditions of 90 DEG C and obtain colourless solution, by au Atomic concentration calculates concentration and is about 0.11mm, saves backup in the refrigerator being placed in 4 DEG C.

The method that the fluorescence gold nanoclusters of triazole parcel measure lemon yellow, concentration is wrapped up for 0.0385mm 1.4ml triazole Fluorescence gold nanoclusters, 500ul 30mm ph be 3.0 phosphate buffered solution, and lemon yellow solution or other chaff interferences Matter, sequentially adds in the centrifuge tube of 5ml, and is settled to 4ml with ultra-pure water, then shakes up and balances 5 minutes at 25 DEG C, finally exists λ_exMeasure its fluorescence intensity during=315nm, measure lemon yellow by spectrum analyses

The present invention has synthesized the water soluble fluorescence gold nano cluster (tro- that 3- sulfydryl -1,2,4- triazole (tro) protects Auncs), gold nano-material is combined with analysis and detection technology, using tro-auncs, there is strong and stable fluorescent emission Matter, as fluorescence molecule, lemon yellow, as quencher, passes through between the two tro-auncsResonance energy transfer makes fluorescence The fluorescence of molecule tro-auncs is quenched.The present invention is based on principles above, establishes a kind of simple, quickly to beverage The detection method of middle lemon yellow.

Brief description

Figure -1 is the chemical structural drawing of lemon yellow (tz)；

Figure -2 is the UV-visible absorption spectrum of tro-auncs；

Figure -3 is tro-auncs fluorescence excitation (a) and launching light spectrogram (b)；

Figure -4 is the infrared spectrogram of tro (a) and tro- gold nano cluster (b)；

The fluorescence spectra of the tro-auncs that figure -5 (a) synthesize for differential responses ratio；

Figure -5 (b) are the fluorescence spectra of the tro-auncs of another ratio synthesis；

Figure -6 is the fluorescence intensity schematic diagram of the tro-auncs of synthesis under different ph；

The fluorescence spectra of the tro-auncs that figure -7 (a) synthesize for different time；

Figure -7 (b) are the fluorescence spectra of the tro-auncs of another time synthesis；

Figure -8 is synthesis and the sensing detection lemon yellow schematic diagram of tro-auncs；

Figure -9 is ultra-violet absorption spectrum (b) overlay chart with lemon yellow for the fluorescence emission spectrum (a) of tro-auncs；

Figure -10 is the impact figure to fluorescent quenching for the ph；

Figure -11 is the impact figure to fluorescent quenching for the tro-auncs concentration；

Figure -12 is the impact figure to system fluorescent quenching for the reaction temperature；

The figure impact figure to system fluorescent quenching for -13 response time；

Figure -14 is the interference test figure of lemon yellow and tro-auncs system；

Figure -15 (a) are the fluorescence quenching curve to system for the lemon yellow；

Figure -15 (b) are the linear relationship chart of fluorescent quenching and lemon yellow concentration.

Specific embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation description is it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments, is based on Embodiment in the present invention, those of ordinary skill in the art obtained under the premise of not making creative work all its His embodiment, broadly falls into the scope of protection of the invention.

Experimental section

1 instrument

Key instrument used by this experiment is shown in Table 1:

Table 1 key instrument

2 reagent

Main agents used by this experiment are shown in Table 2:

Table 2 main agents

3 test methods

The synthesis of the water-soluble gold nano cluster that 3.1 tro modify

The present invention has synthesized the water-soluble gold nano cluster with fluorescence property of tro modification using hydro-thermal method.Concrete system Preparation Method is as follows: adds the haucl of 1.0ml, 10mm in the there-necked flask fill 80ml triple distillation water₄Aqueous solution；Then Under conditions of being stirred vigorously, add 3- sulfydryl -1 of 5.0ml, 10mm, 2,4- triazole aqueous solutions, adjust solution with the hcl of 1m Ph be 3 about；React 13 hours under the conditions of 90 DEG C and obtain colourless solution, concentration is about 0.11mm (based on au atomic concentration Calculate), save backup in the refrigerator being placed in 4 DEG C.

The sign of 3.2 tro-auncs

Record the uv absorption spectra of material using uv-2550 ultraviolet-uisible spectrophotometer.Using nicolet 6700 type Fourier transformation infrared spectrometers, kbr pressed disc method measures 4000-500cm respectively^-1Interior tro and tro-auncs.Using Jsm-6510 scanning electron microscope and supporting eds are analyzed to gold nanoclusters element.Gold nanoclusters fluorescence spectrum is surveyed Surely utilize cary eclipse fluorophotometer, excite and be 10nm with transmite slit width, survey under the excitation wavelength of 315nm It launches spectrogram.

The preparation of 3.3 lemon yellow storing solutions

Accurately weigh the lemon yellow of 0.0053g, with being settled to after water dissolution in 100ml volumetric flask, obtain lemon yellow deposit Liquid concentration is 0.1mm, is placed in 4 DEG C of Refrigerator store, is diluted to desired concn during experiment.

3.4 fluorescence detection method

The step of detection lemon yellow operates as follows: by 1.4ml tro-auncs, (general concentration is 0.0385mm), 500ul 30mm ph is 3.0 phosphate buffered solution, and the lemon yellow solution of different volumes or other are dry Disturb material, sequentially add in the centrifuge tube of 5ml, and be settled to 4ml with ultra-pure water, then shake up balance 5 minutes at 25 DEG C, Afterwards in λ_exIts fluorescence intensity is measured during=315nm.

4 results and discussion

The ultraviolet-visible spectrum of the auncs that 4.1 tro modify

The absorption spectrum in the ultraviolet-visible light area of the tro- gold nano cluster that figure -2 is 0.11mm for concentration.As seen from the figure, In the wave-length coverage of whole scanning, in addition to the acromion at 315nm, obvious surface plasma resonance is not observed and inhales Receive peak.Document report, when the particle diameter of the gold nanoclusters of single ply protective is less than 2nm, golden nanometer particle feature at 520nm etc. Ionic absorption band will disappear, and this is due to caused by damping effect.Side shows the particle diameter of the tro- gold nano cluster of synthesis Less than 2nm.And the absworption peak at the acromion occurring at the 315nm of ultra-violet (UV) band, with the gold nanoclusters 384nm of 8 atoms of research report Result be similar to, this peak position is the maximum excitation peak position of fluorescence gold nano cluster.Shoulder therefore for tro-auncs, at 315nm Peak value obtains our concerns.

The fluorescence spectrum of the auncs that 4.2 tro modify

, as dressing agent, at 90 DEG C, the fluorescence excitation of auncs of 13 hour preparations of reaction and emission spectrum are as schemed -3 for tro Shown, scan the fluorescence excitation that obtains and transmitting position be respectively 315nm and 401nm, fluorescence exciting wavelength 315nm at and Acromion 315nm observed by figure -2 is consistent.Do not produce after the auncs solution of gained is placed 6 months in 4 DEG C of refrigerator Precipitation, its fluorescence intensity reduces only about 9%, shows that the fluorescence gold nano cluster synthesizing can steady in a long-term in aqueous be deposited ?.By in process of the test using the reagent arriving such as gold chloride, 3- sulfydryl -1,2,4- triazole, gold chloride and 3- sulfydryl -1,2,4- three The mixed solution of azoles, water etc. are all determined under the conditions of identical fluorometric investigation, and fluorescence phenomenon is not observed, and auxiliary is said Understand the successful synthesis of the water solublity auncs that the tro with strong and stable fluorescent emission property modifies.

Fourier transform infrared spectroscopy (ftir) analysis of 4.3 tro-auncs

For confirming part 3- sulfydryl -1,2,4- triazoles (tro) are combined with the success of gold nano cluster, determine its combination simultaneously Mode, employs Fourier transform infrared spectroscopy (ftir) and auncs and tro part is studied, measurement result such as figure -4 Shown in (a) and (b).Can obtain from this in figure: part tro is in 2620cm^-1The stretching vibration peak of-sh in place.Contrast tro protects The infrared spectrum of the auncs (tro-au nps) of shield, the latter's peak number is less, and 2620cm^-1- sh the stretching vibration peak at place disappears, Sulfydryl on tro after being primarily due to react has carried out coordination with gold atom surface by au-s key and has combined.It can thus be appreciated that part Tro and au there occurs coordination, forms stable au-s key and stops the auncs of generation from reuniting, and plays and modifies and steady Determine the effect of auncs.Shown by the energy dispersive x-ray spectrum analyses of tro-auncs, contain in the gold nano-material of synthesis N, c, s, au element, aids in illustrating tro-auncs and synthesizes successfully.

The investigation of 4.4 tro-auncs synthesis conditions

4.4.1 the investigation of reactant ratio

Experimentation finds, the mol ratio of different part and gold chloride can affect the glimmering of the gold nano-material of synthesis Optical property, the gold nano-material higher in order to obtain fluorescence intensity, our reaction ratios to 1:1,3:1,5:1,7:1,9:1 respectively Example is investigated, and experimental result is as schemed shown in -5 (a) and (b).It can be seen that when reaction ratio is 1:1, synthesis gold Nanometer solution is in light red, has characteristic absorption peak, show have bulky grain gold nano to be formed at 520nm, and significantly not glimmering Optical property；With the increase of reaction ratio, tro-auncs fluorescence intensity gradually strengthens, in reaction than tro-auncs during for 5:1 Fluorescence intensity reach maximum；With reaction ratio continue increase, fluorescence intensity reduce on the contrary it may be possible to due to modify in Jenner The part on rice surface has reached saturation, and the interaction between excessive part causes the gathering of gold nanoclusters, leads to fluorescence intensity Reduce.To sum up, the optimal synthesis ratio selecting in this test is 5:1.

4.4.2 the investigation of reaction acidity

The fluorescence gold nanoclusters aqueous solution of tro parcel is very sensitive to the change of system acidity, therefore reaction acidity is entered Go investigation.In the range of ph is for 1-11 tro-auncs solution fluorescence Strength Changes as figure -6 shown in, in ph=1.00～3.00 Acidity Range in, the tro-auncs of synthesis is clear solution, and increases fluorescence intensity level with system ph and be gradually increased；Work as ph =3.00 about, tro-auncs solution fluorescence intensity reaches maximum；Continuation then as ph increases, the tro-auncs of synthesis Fluorescence intensity reduces on the contrary.And in ph > after 6.00, the gold nanoclusters solution of synthesis starts to become cloudy, and has agglomeration to produce, White precipitate occurs.The tro-auncs solution synthesizing as can be seen here can not stable existence in the basic conditions.Therefore in order to prepare Go out stable, hyperfluorescence emitting performance gold nano cluster solution, the system optimum response acidity of test final choice is ph= 3.00.

4.4.3 the selection in response time

For the impact of the spectrum property to synthesis tro-auncs for the research response time, test and determine synthesis tro-auncs During between 1-15h solution fluorescence spectrum, result is as shown in figure -7.The tro-auncs's that figure -7 (a) synthesize for different time Fluorescence spectra, figure -7 (b) are the fluorescence spectra of the tro-auncs of another time synthesis；As can be seen from the figure with anti- Should, the increase of time, the fluorescent emission peak intensity of tro-auncs gradually strengthens, to 13h about fluorescence intensity reach maximum, so After increase over time fluorescence intensity kept stable, and the position of fluorescence emission peak is not moved substantially.Therefore, for obtaining The gold nano cluster of stable hyperfluorescence emission characteristic, the optimum reacting time selecting in experiment is 13h.

4.5 water solublity tro-auncs are as the fluorescent probe of detection lemon yellow

The preparation process of gold nano cluster of water solublity tro protection and fluorescence sense detect the schematic diagram of lemon yellow as schemed -8 Shown.With tro and gold chloride as raw material, the gold nanoclusters solution that solution ph prepares is adjusted in excitation wavelength with the hcl of 1m There is under 315nm strong fluorescent emission.Add after lemon yellow to system, the fluorescence of gold nano cluster solution occurs substantially to be quenched now As.

Figure -9 wraps up the overlapped spectra of the fluorescence emission spectrum of gold nanoclusters and the ultraviolet-visible spectrum of lemon yellow for tro. It is observed that the two spectrogram there occurs significantly overlap, speculate between lemon yellow and gold nanoclusters it is by fluorescence with this Resonance energy transfer (fret) leads to the fluorescence of fluorescence molecule tro-auncs to be quenched.For confirm this guess we made with Lower research.Theoretical according to the Nonradiative energy transfer of foster, energy transfer following several under the conditions of just can occur；A () gives Being spaced between 2-8nm between body and receptor；B () gives effective overlapping between the fluorescence peak of body and the absworption peak of receptor；(c) Give being suitably oriented between body and the dipole of receptor.Give the distance between body and receptor and energy transfer efficiency can be by equation (4-1), (4-2), (4-3) calculate:

$e=1-\frac{f}{f_0}=\frac{r_0^6}{r_0^6+r^6}---(4-1)$

r₀ ⁶=8.8 × 10^-25k²n^-4φj (4-2)

$j=\frac{{\&integral;}_0^{\mathrm{\∞}}f\left(\mathrm{\λ}\right)\mathrm{\ϵ}\left(\mathrm{\λ}\right){\mathrm{\λ}}^{4}d\mathrm{\λ}}{{\&integral;}_0^{\mathrm{\∞}}f\left(\mathrm{\λ}\right)d\mathrm{\λ}}---(4-3)$

Wherein, r represents the interval giving between body and receptor；r₀Represent and calculated by above equation when rate of energy transfer is 50% The distance obtaining；k²It is the orientation factor given between body-acceptor dipoles；N is the refractive index of medium；φ is the fluorescent quantum giving body Yield；J represents and gives the fluorescence emission peak of body the overlapping degree peak-to-peak with the absorption of receptor；F (λ) is that to give body glimmering in af at wavelength lambda Light intensity；ε (λ) is the molar absorption coefficient in af at wavelength lambda for the receptor.In above equation, k²=2/3, n=1.36, φ= 0.13, substituted into equation (4-1), (4-2), (4-3), drawn j=5.83 × 10^-15cm³·l·mol^-1, e=0.3287, r₀ =3.38nm, r=4.83nm.The r value drawing is less than 8nm, illustrates to be implicitly present in phase interaction between tro-auncs and lemon yellow With, and very likely there occurs energy transfer.In conjunction with the two fluorescent emission and ultraviolet spectra obvious overlapping, show tro- As energy donor, lemon yellow, as energy acceptor, there occurs Resonance energy transfer (fret), thus leading to auncs between the two The fluorescent quenching to tro-auncs for the lemon yellow.And test the fluorescent quenching degree finding lemon yellow concentration and gold nano cluster Assume good linear relationship, based on this we using water miscible tro-auncs as detection lemon yellow fluorescent probe.For obtaining Obtain more sensitive detection signal, and to a series of as experiment conditions such as ph, gold nanoclusters consumption, reaction temperature and response time It is optimized.

4.5.1 the impact to quenching efficiency for the ph

The tro-auncs of present invention synthesis is unstable under alkaline environment, has precipitation to produce and fluorescent emission intensity pole Low, therefore test and mainly investigated the impact to system fluorescence intensity for the ph in acid range.Experimental implementation is as follows: to 8 5ml from It is separately added into 1.4ml tro-auncs (general concentration is 0.0385mm), the 500 μ l 30mm ph phosphate in 1-6 in heart pipe Buffer solution, and lemon yellow molten, the constant volume to 4.0ml of deposit of 100 μm of 0.5ml, mix homogeneously.5min is balanced at 25 DEG C Afterwards, measure its fluorescence intensity., as shown in figure -10, when ph≤3.0, the fluorescent quenching efficiency of system is with the increasing of ph value for result Greatly and gradually strengthen；When ph >=3.0, the fluorescent quenching efficiency of system drastically reduces with the increase of ph value；Work as ph=3.0 When, the fluorescence intensity of system and fluorescent quenching efficiency all reach maximum, and reaction is the sensitiveest, and the linear pass now obtaining System is good.Therefore, this experiment chooses 3.0 as the optimal ph value detecting lemon yellow.

4.5.2 the selection of tro-auncs consumption

The concentration of tro-auncs not only can affect the fluorescent emission intensity of system, also can be to the sensitivity of detection object And linear working range causes serious impact, thus other experiment test conditions ibid in the case of, this experiment is to tro-auncs Concentration investigated in the range of 0.0055-0.0550mm.Result as figure -11 shown in, with the increasing of tro-auncs concentration Plus, fluorescent quenching efficiency is in increase tendency；Reach maximum in 0.0385mm, then as the increase of tro-auncs concentration, The fluorescent quenching efficiency of system is gradually lowered.When the reason this phenomenon is likely due to tro-auncs excessive concentration, produce The self-quenching of tro-auncs.Therefore, in order to obtain satisfied detection signal, last experimental selection gold nanoclusters dense Spend for 0.0385mm.

4.5.3 the investigation of reaction temperature

Because, in the mensure of fluorimetry, reaction temperature can produce shadow to tro-auncs-tz system fluorescence intensity Ring, therefore, other experiment test conditions ibid in the case of, the present invention has investigated the shadow to system fluorescent quenching efficiency for the temperature Ring.As shown in figure -12, when temperature is 25 DEG C, system fluorescent quenching efficiency is the strongest.When reaction temperature is less than 25 DEG C or height When 25 DEG C, fluorescent quenching efficiency is all relatively low.This illustrates that low temperature and high temperature are all unfavorable for the carrying out of reaction.Therefore, according to experiment As a result, the present invention selects optimal reaction temperature is 25 DEG C.

4.5.4 the investigation in response time

Under the conditions of 25 DEG C of room temperature, investigate the shadow of the fluorescent quenching efficiency to tro-auncs-tz system for the response time Ring.As shown in figure -13, from 0-5min, fluorescent quenching efficiency strengthens obvious experimental result；When 5min, system is glimmering Optical quenching degree reaches maximum；After 5min, fluorescent quenching efficiency tends towards stability and fluorescence intensity change is little.This explanation is whole Reaction completes in 5min, is capable of the quick detection of lemon yellow in actual sample.Therefore this experimental selection is in 25 DEG C of room temperature Detected after lower reaction 5min.

4.5.5 the interference test of coexisting substances

In order to study further the present invention led to based on the FRET (fluorescence resonance energy transfer) between tro-auncs and lemon yellow glimmering The selection implementations to lemon yellow in detection actual sample for the fluorescent probe prepared by optical quenching principle, if the present invention is to beverage The interfering material that may be coexisted with lemon yellow in juice, orange juice is investigated.Result is shown in Figure 14, finds to work as na⁺、k⁺、ca²⁺、mg^{2 +}、zn²⁺、cl^-、no₃ ^-、so₄ ^2-、co₃ ^2-、ch₃coo^-, glucose, Fructose isoconcentration be when being 150 times of lemon yellow concentration, will not be right Detection lemon yellow produces impact；Work as cr³⁺, vitamin c, rhodamine b, methylene blue concentration is when being 30 times of lemon yellow, will not be to lemon The yellow detection of lemon causes too big interference.

Scheme the interference test of -14 lemon yellow and tro-auncs system, the concentration of phosphate buffer ph=3.0, tz is 5.93μm；Na+, k+, zn2+, mg2+, ca2+, cl-, no3-, so42-, co32-, ch3coo-, glucose, the concentration of Fructose are 0.89mm；Cr3+, vitamin c, rhodamine b, the concentration of methylene blue are 0.18mm.

To sum up, some common food additive and common inorganic ion in the range of finite concentration for lemon yellow Detection by quantitative all have no significant effect.Confirm that the method can be with lemon yellow in the actual beverage of selective enumeration method.

4.6 methodological study

4.6.1 the drafting of standard curve

System is the phosphate buffered solution that ph is 3.0 in the optimum condition selecting, and concentration is the tro- of 0.0385mm Auncs solution, action time is 5.0min, and at reaction temperature is 25 DEG C, the lemon yellow storing solution adding different volumes is so as to Final concentration is respectively 0.00,0.08,0.90,1.50,2.50,5.00,7.50,10.00,12.50,17.50,22.50,27.50, 32.50 and 37.50 μm, measure its fluorescence intensity.Obtain fluorescence spectrum such as figure -15 (a) adding variable concentrations lemon yellow system Shown it can be seen that addition with lemon yellow, the fluorescence intensity of tro-auncs is gradually lowered；With tz concentration as abscissa, glimmering Light intensity is quenched degree (f₀/ f) draw standard curve for vertical coordinate, such as shown in figure -15 (b).Test the linear regression side obtaining Journey is f₀/ f=0.9817+0.0514c (r²=0.9993).Show, lemon yellow concentration is in 0.08～37.50 μ m and body Be the quenching degree of fluorescence intensity be in good linear relationship, the relative mark of 11 parallel laboratory tests of lemon yellow of 12.50 μm of detection Quasi- deviation (rsd) is 2.7%, and test limit (3 σ/k) is 0.028 μm.

4.6.2 beverage full pattern recovery of standard addition and precision test

In order to investigate the full pattern analysis ability of this fluorescent probe, it is applied to actual beverage fruit juice, orange juice, lemon in Mel The yellow mensure of lemon.The process of sample: shake up uniform to guarantee sample before corkage, accurately pipette sample 1ml in the centrifuge tube of 15ml In, it is diluted to 10ml, ultrasonic echography 15min with ultra-pure water, the filter membrane crossing 0.45um is with to be detected.

The response rate is tested: by the analysis mensure to beverage fruit juice, orange juice, Mel, it was found that not having in fruit juice and Mel It is found the presence of lemon yellow；0.21 μ μ lemon yellow is detected in orange juice to exist.In order to investigate accuracy and the precision of the method Degree, the standard sample of lemon yellow is added to fruit juice, orange juice, in honey sample, carries out response rate experiment to it by this experiment.

Precision test: 0.0385mm tro-auncs solution, 0.5ml ph is 3.0 phosphate buffered solution, and one Quantitative actual sample, adds the lemon yellow storing solution of different volumes, is settled to 4ml, makes the Fructus Citri Limoniae that fruit juice and Mel add The ultimate density of yellow basic, normal, high three levels is respectively 0.40,4.00,8.00um；The concentration of lemon yellow that orange juice adds is made to be 0.5-2.0 times of actually detected content is that ultimate density is respectively 0.20,0.30,0.40um.Parallel 3 parts of each concentration, 25 DEG C Measure after balance 5min in thermostatic water bath.Not plus actual sample and lemon yellow storing solution as blank group.By above-mentioned sample In a few days, replication 3 times in the daytime, calculate relative standard deviation (rsd) in a few days, in the daytime, experimental result is shown in Table 3.

This experiment obtains in a few days and in the daytime response rate scope and is respectively fruit juice 949%-95.53% and 88.8%0- 99.27%th, orange juice 92.60%-102.15% and 89.25%-92.65%, Mel 92.38%-105.02% and 90.24%- 103.40%, response rate result is preferable.Rsd is respectively fruit juice 2.81%-4.48% and 3.16%-5.91%, orange juice 2.90%- 6.25% and 2.27%-5.63%, Mel 2.50%-5.54% and 3.36%-5.92%.To sum up, the method has well Reliability, shows that the method that the present invention sets up can be applicable to the mensure of content of tartrazine in actual beverage.

The response rate and Precision test result (n=3) to lemon yellow in the actual beverage of table 3

4.7 methods compare

By comparing discovery with the method for document report, the linearly dependent coefficient r value that method proposed by the present invention obtains is More satisfactory；Though precision is not best, the demand of actually detected lemon yellow can be met；The method of the present invention obtains Test limit (lod) the close even better of 28nm (0.015ppm) and document report can be reached, add far below China's food The sanitary standard setting of agent lemon yellow, i.e. the highest limit standard (0.75ppm) of human body daily intaking amount, therefore the present invention is carried The method going out disclosure satisfy that the needs that in actual sample, lemon yellow measures.

Claims (2)

1. triazole parcel fluorescence gold nanoclusters synthetic method it is characterised in that: to filling three mouthfuls of 80ml triple distillation water burnings The haucl of 1.0ml, 10mm is added in bottle₄Aqueous solution；Then under conditions of being stirred vigorously, add the 3- mercapto of 5.0ml, 10mm Base -1,2,4- triazole aqueous solutions, are 3 about with the ph that the hcl of 1m adjusts solution；Under the conditions of 90 DEG C 13 hours of reaction obtain colourless Solution, calculates concentration by au atomic concentration and is about 0.11mm, save backup in the refrigerator being placed in 4 DEG C.

2. usage right require 1 synthesis triazole parcel fluorescence gold nanoclusters measure lemon yellow method it is characterised in that: will Concentration be 0.0385mm 1.4ml triazole parcel fluorescence gold nanoclusters, 500ul 30mm ph be 3.0 phosphate-buffered molten Liquid, and lemon yellow solution or other interfering materials, sequentially add in the centrifuge tube of 5ml, and are settled to 4ml with ultra-pure water, so After shake up at 25 DEG C balance 5 minutes, finally in λ_exMeasure its fluorescence intensity during=315nm, measure Fructus Citri Limoniae by spectrum analyses Yellow.