CN113670867A - Supermolecule fluorescence sensing array and method for detecting multiple metal ions in aqueous solution - Google Patents

Abstract

The invention discloses a supermolecule fluorescence sensing array and method for detecting multiple metal ions in water solution, the supermolecule fluorescence sensing array includes RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]The detection method of the three supramolecular fluorescent probes comprises the following steps: a supramolecular fluorescence sensing array; prepare a group of Ba²⁺、Hg²⁺、Fe²⁺、Fe³⁺、Pb²⁺、Al³⁺And Cr²⁺A metal ion standard solution; detecting a data matrix; analyzing the data matrix by software to obtain a standard model; adding RhB @ Q [7] into the aqueous solution to be detected respectively]、H33342@2Q[7]And BER @ Q [7]]And (3) detecting the fluorescence spectrum and the maximum emission fluorescence intensity in the three supramolecular fluorescent probes, and inputting the detection value into the standard model to obtain a detection result. The supermolecule fluorescence sensing array for detecting various metal ions in aqueous solution provided by the invention can detect Ba²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺The 7 metal ions are qualitatively detectedCompared with the traditional detection technology, the method is more intuitive and convenient.

Description

Supermolecule fluorescence sensing array and method for detecting multiple metal ions in aqueous solution

Technical Field

The invention belongs to the technical field of analytical chemistry, and particularly relates to a supermolecular fluorescence sensing array and a method for detecting multiple metal ions in an aqueous solution.

Background

With the rapid development of industrial civilization, the environmental pollution problem gradually becomes a worldwide problem, and the public of all countries attracts high attention. Heavy metal wastewater (containing heavy metal ions such as barium, chromium, mercury, lead and the like) generated in the industrial production processes such as mining and metallurgy, mechanical manufacturing, chemical industry, electronics, instruments and the like has serious harm to human health and environment, can pollute soil and cause heavy metal enrichment of crops and aquatic organisms.

At present, a plurality of methods for identifying metal ions are available. Such as atomic absorption spectrometry, high performance liquid chromatography, spectrophotometry, etc., have high accuracy and sensitivity, but require expensive instruments and professional detection technicians, which is costly. Also, heavy metal contaminants often coexist in multiple mixtures, thus confusing the analysis, and how to detect and distinguish target analytes is a challenge. Therefore, it is significant to design a simple, sensitive and rapid method for detecting various metal ions in water.

Disclosure of Invention

The invention aims to provide a supermolecule fluorescence sensing array and a method for detecting various metal ions in an aqueous solution²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺Compared with the traditional detection technology, the 7 metal ion qualitative detection method is more visual and convenient.

The invention adopts the following technical scheme to realize the purpose of the invention:

a supermolecule fluorescent sensing array for detecting multiple metal ions in water solution is composed of three supermolecule fluorescent probes, RhB @ Q7, H33342@2Q 7 and BER @ Q7.

In the supermolecule fluorescence sensing array for detecting various metal ions in the aqueous solution, the RhB @ Q7 supermolecule fluorescence probe is prepared by mixing a Q7 solution and a RhB solution with a molar ratio of 1: 1.

In the supermolecule fluorescence sensing array for detecting various metal ions in the aqueous solution, the H33342@2Q 7 supermolecule fluorescence probe is prepared by mixing the Q7 solution and the H33342 solution with the molar ratio of 2: 1.

In the supermolecule fluorescence sensing array for detecting various metal ions in the aqueous solution, the BER @ Q7 supermolecule fluorescence probe is prepared by mixing Q7 solution and BER solution with the molar ratio of 1: 1.

In the supermolecular fluorescence sensing array for detecting multiple metal ions in aqueous solution, the RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]The concentration of three supramolecular fluorescent probes is 1 multiplied by 10^-5mol/L of RhB @ Q [7]]Supramolecular fluorescent probes.

A method for detecting a plurality of metal ions in an aqueous solution, comprising the steps of:

(1) preparing a group of the supermolecule fluorescence sensing array;

(2) prepare a group of Ba²⁺、Hg²⁺、Fe²⁺、Fe³⁺、Pb²⁺、Al³⁺And Cr²⁺A metal ion standard solution;

(3) each metal ion standard solution is respectively added into a supermolecule fluorescence sensing array to obtain a mixed sample solution, a group of data is obtained by detecting the fluorescence spectrum and the maximum emission fluorescence intensity of the mixed sample solution, and a data matrix consisting of 3 sensing elements, 7 metal ions and 5 parallel experiments is obtained by performing more than 2 parallel experiments;

(4) analyzing the data matrix by software to obtain a standard model;

(5) providing 3 parts of aqueous solution to be detected, respectively adding into three kinds of supermolecule fluorescent probes of RhB @ Q7, H33342@2Q 7 and BER @ Q7, detecting fluorescence spectrum and maximum emission fluorescence intensity, inputting the detected value into a standard model to obtain a detection result.

In the method for detecting multiple metal ions in an aqueous solution, in the step (2), the concentration of the metal ion standard solution is 50 times that of the supramolecular fluorescent probe.

In the foregoing method for detecting a plurality of metal ions in an aqueous solution, the step (4) is: performing linear discriminant analysis on the data matrix by using SPSS software to obtain a standard model; the standard model is the LDA model.

Compared with the prior art, the invention has the following beneficial effects:

1. the present invention uses three kinds of guest molecules, rhodamine B (RhB), Hoechst 33342(H33342) and berberine hydrochloride (BER), which have great difference with each other to respectively react with Q7]Construct RhB @ Q [7]]、 H33342@2Q[7]And BER @ Q [7]]Three fluorescent probes form a cucurbituril supramolecular fluorescent sensing array. The Ba can be changed by utilizing different responses of the sensing array to different metal ions, namely, the change of fluorescence under ultraviolet visible absorption spectrum, fluorescence emission spectrum and 365nm ultraviolet lamp²⁺,Hg²⁺,Fe²⁺, Fe³⁺,Pb²⁺,Al³⁺,Cr²⁺The 7 metal ions are identified and detected, the detection method has the characteristics of simplicity, sensitivity, rapidness and effectiveness, and the detection method provided by the invention is more intuitive and convenient than the traditional detection technology.

2. Today, the environmental protection requirement is higher and higher, and the monitoring and detection of environmental pollutants with complex components are very important for environmental protection and human health. The optical sensing array is an array composed of sensing units with broad-spectrum cross response and has the capability of detecting and monitoring complex mixtures. The cucurbituril has a hydrophobic cavity and an electronegative carbonyl port, and can react with some guest molecules to form a fluorescent probe with optical response. The invention provides RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]Three fluorescent probes are used for constructing a cucurbit uril supramolecular sensing array system, and 7 metal ions (Ba) in the aqueous solution can be identified and detected by utilizing different responses of each sensing element in the fluorescent sensing array to different metal ions²⁺, Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺)。

3. The invention forms a supermolecule fluorescent probe based on 3 object molecules and a cucurbituril, and respectively makes the system fluorescence generate strong sensitization. RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]Three fluorescent probes, 365n, have large differences in properties between themm under the irradiation of ultraviolet lamp, RhB @ Q7]Fluorescent light is bright yellow, H33342@2Q [7]]Blue-blue fluorescence, BER @ Q7]The fluorescence appears bright green. When Ba is present²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺The 7 metal ions are added to RhB @ Q [7]]、 H33342@2Q[7]And BER @ Q [7]]Three fluorescent probes have different response modes and response degrees for the 7 metal ions. The fluorescent color of 3 probes under 365nm ultraviolet lamp irradiation is taken to design a fluorescent color array of 3 sensing elements multiplied by 7 metal ions, and the fluorescent color of each metal ion is compared through a matrix. Meanwhile, by a statistical method, the response spectrum of the 7 metal ions on the sensor array system is subjected to pattern recognition by using Linear Discriminant Analysis (LDA), and the response condition of the sensor array system to a sample to be detected is evaluated, so that the purpose of detecting Ba in the aqueous solution is realized²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺These 7 methods of detecting metal ions.

4. The invention provides a preferable RhB @ Q7 supramolecular fluorescent probe which is prepared by mixing a Q7 solution and a RhB solution with a molar ratio of 1: 1; h33342@2Q 7 supramolecular fluorescent probe is prepared by mixing Q7 solution and H33342 solution in a molar ratio of 2: 1; the BER @ Q7 supermolecule fluorescent probe is prepared by mixing a Q7 solution and a BER solution with a molar ratio of 1:1, thereby ensuring that each probe has good fluorescence performance.

Specific bases for the above molar ratios are proposed:

(1) the inventors studied RhB and Q [7] using fluorescence emission spectroscopy]The binding behavior of (c). From 584nm N_RhB/N_Q[7]As can be seen from the relationship between the fluorescence intensity (FIG. 9b) and the Job method (FIG. 9b inset), RhB and Q [7]]The action ratio of (A) to (B) is 1: 1. Subsequently, the inventors continued to use¹HNMR spectra investigated RhB and Q [7]]The binding behavior of RhB @ Q [7] was found]Is Q < 7 >]And 1:1 dynamic equilibrium with one of the two N, N-diethylamino groups on RhB (FIG. 9 c).

Thus, from the fluorescence emission spectrum¹Research and invention of HNMR spectrumHuman discovery of RhB and Q [7]]The mode of action is 1:1 inclusion, and the N, N-diethylamino group on RhB has an inclusion of Q7]Resulting in a significant enhancement of the fluorescence properties of RhB.

(2) First, the fluorescence spectrum is used to study H33342 and Q7]The binding behavior of (c). When Q7 is lower]When added to the H33342 solution, when C_Q[7]/C_H33342When the ratio of (A) to (B) is-2.0, the fluorescence intensity gradually increases and the emission spectrum shows a large blue shift; continuing to add Q [7]]The emission spectrum again shows a large red shift (fig. 10 a). This indicates that the gradual inclusion mode is applicable in this case. That is, a 1:1 host-guest complex is formed in the initial stage, and then a 2:1 host-guest complex is formed in the later stage. Next, the inventor uses¹HNMR titration investigated Q [7]And H33342. As shown in FIG. 10c, the concentration of H33342 was fixed at 1X 10^-4mol·L^-1Gradually adding Q7 to the inside]. When Q < 7 >]When the dropping ratio reaches 1:1, the proton resonance peak of the piperidine (Pip) part of H33342 and the proton resonance peak of the benzimidazole (Bz1) part undergo a significant high field shift, and the proton peak of the PhOEt ring and the proton resonance peak of the ethyl group part of the benzimidazole (Bz2) part move to a low field. This indicates that when H33342 and Q [7]]1:1 when acting, H33342 part Pip is included in Q7]In the cavity of (a). Continuing to add Q7 into the system]To C_Q[7]/C_H33342At 1:2, the benzene ring on Bz2 moves slightly low-field, but the protons on the ethyl group and those on the benzene ring on pheet move high-field compared to the 1:1 host-guest inclusion, indicating that a second Q [7] appears when the second Q [7] occurs]The time portion PhOEt is also encapsulated in Q7]And (4) in the cavity.

Thus, from the fluorescence emission spectrum¹Study of HNMR spectra, H33342 and Q [7]]There are two modes of action: when Q < 7 >]In less, H33342 and Q7]Forming a 1:1 complex; continue to increase Q7]H33342 and Q [7]]Will form a 1:2 stable complex.

(3) BER and Q7 were investigated by fluorescence emission spectroscopy]The binding behavior of (c). BER (10 μm) is self-non-fluorescent, Q7]The effect of concentration on fluorescence intensity is shown in FIG. 11a, with Q7]Increase of BER and Q [7]]Consistent with our invention, the fluorescence also gradually increases when Q7]Increase to 3At 0 μ M, the fluorescence intensity increased by about 65-fold at a wavelength of 553 nm. From N at 500nm_BER/N_Q[7]The relationship between the fluorescence intensity (FIG. 11b) and the Job method (FIG. 11b) can be illustrated, BER and Q7]The action ratio of (A) to (B) is 1: 1. Then continue to use¹HNMR spectroscopy study Q [7]]The binding behavior with BER. When Q7 is added to BER solution]When the proton (marked as a') on the group of alkoxy groups attached to the left side of the quinoline ring splits into two sets of peaks and gradually moves to a high field, and H on the quinoline ring_b,H_c，H_d，H_jAll moving towards the high field. However, H in the BER guest molecule_i，H_e，H_g，H_fAre moving towards the low field. Therefore, BER and Q [7]]When interacting, quinoline ring and partial alkoxy are wrapped in Q7]E.g., as shown in fig. 11 c.

From fluorescence emission spectra and¹the inventors of HNMR spectrum research can find that BER is related to Q7]In a ratio of 1:1, and the quinoline ring and partial alkoxy group on the BER are enclosed in Q7]In the hydrophobic cavity of (FIG. 11c top), BER is associated with Q7]The fluorescence property is enhanced by about 15 times after the formation of the host-guest complex.

5. The invention provides RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]The preferred concentration of the three supramolecular fluorescent probes is 1 × 10^-5mol/L based on when selecting RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]The concentration of three supramolecular fluorescent probes is 1 multiplied by 10^-5At mol/L, three types of guest molecules, namely RhR, H33342 and BER, can not aggregate. At the same time, H33342@2Q [7]]The ultraviolet absorption intensity of the fluorescent material reaches 0.37, and the fluorescence emission intensity reaches 460; BER @ Q [7]]The ultraviolet absorption intensity of the fluorescent material reaches 0.44, the fluorescence emission intensity reaches 687, and the experimental analysis requirements are met.

6. The invention proposes that the concentration of the metal ion standard solution is 50 times of the concentration of three supramolecular fluorescent probes according to the conditions that figure 12, figure 13 and figure 12 are RhB @ Q7 respectively]、H33342@2Q[7]And BER @ Q [7]]The three probes (all at a concentration of 1X 10)^-5mol/L) of the metal ions in the solution 7 respectively, and can find that when the concentration of the metal ions is increased to 50 times of that of the probes, the three types of probes almost completely react with the metal ionsThe effect of the response, therefore a 50-fold concentration was chosen as the selection condition.

Drawings

FIG. 1 is a graph showing fluorescence emission spectra and fluorescence intensity changes of RhB @ Q7 (a-b), H33342@ Q7 (c-d) and BER @ Q7 (e-f) in the presence of 7 kinds of metal ions (500. mu.M);

FIG. 2 is a graph showing the change in fluorescence color under a 365nm ultraviolet lamp of RhB @ Q7 (a), H33342@ Q7 (b), BER @ Q7 (c) in the presence of 7 metal ions;

FIG. 3 is a color matrix plot of the fluorescence color of RhB @ Q7, H33342@2Q 7 and BER @ Q7 under 365nm UV light in the presence of 7 metal ions;

FIG. 4 is a graph of linear discriminant analysis of the fluorescence response of 7 metal ions in pure water;

in FIG. 5, Pb is different²⁺A linear discriminant analysis plot of the concentration fluorescence response;

FIG. 6 shows fluorescence spectrum (a) and ultraviolet absorption spectrum (c) when RhB (10. mu.M) is increased in Q7 concentration, respectively; NRhB/NQ 7 fluorescence intensity dependence curve (b), insert: job plots obtained by continuously varying the mole fractions of RhB and Q < 7 >; enlarging detail of ultraviolet absorption spectrum part when RhB respectively increases Q7 (10 μ M) concentration;

FIG. 7 shows fluorescence spectra and UV absorption spectra of H33342(10 μ M) at increasing Q7 concentrations, respectively; NBER/NQ 7 fluorescence intensity curve; NBER/NQ 7 ultraviolet absorption curve;

FIG. 8 shows fluorescence spectrum (a) and ultraviolet absorption spectrum (c) when BER (10. mu.M) is increased in Q7 concentration, respectively; NBER/NQ [7] fluorescence intensity relationship curve (b) insert: job plots obtained by continuously varying BER and the mole fraction of Q < 7 >; NBER/NQ [7] UV absorption curve (d) insert: job plots obtained by continuously varying BER and the mole fraction of Q < 7 >;

FIG. 9 shows fluorescence spectra (a) when RhB (10. mu.M) was increased in Q7 concentration, respectively; NRhB/NQ 7 fluorescence intensity dependence curve (b), insert: job plots obtained by continuously varying the mole fractions of RhB and Q < 7 >; possible interaction modes between RhB and Q < 7 > (c top); 1H NMR titrimetric spectrum with CQ 7/CRhB added as (a)0, (b)0.5, (c)1.1, (d)1.8, (e)2.8(c bottom);

FIG. 10 shows fluorescence spectra (a) of H33342 (10. mu.M) with increasing Q7 concentration, respectively; NRhB/NQ 7 fluorescence intensity relation curve (b); possible interaction pattern between H33342 and Q7 (c top); 1H NMR titrimetric spectrum with the addition of CQ [7]/C H33342 of ((a)0, (b)0.5, (c)0.7, (d)1.5, (e)1.8, (f)2.5 (bottom of c)

FIG. 11 shows fluorescence spectra (a) when BER (10. mu.M) was increased in Q7 concentration, respectively; NRhB/NQ 7 fluorescence intensity dependence curve (b), insert: job plots obtained by continuously varying BER and the mole fraction of Q < 7 >; possible interaction patterns between BER and Q < 7 > (c Top); 1H NMR titrimetric spectrum with CQ [7]/CBER added (a)0, (b)0.5, (c)0.8, (d)1.2 (bottom of c);

FIG. 12 is Ba²⁺，Hg²⁺，Fe²⁺，Fe³⁺，Pb²⁺，Al³⁺，Cr³⁺For RhB @ Q [7]]Fluorescence spectra of (10. mu.M) titration, inset: N_Mn+/N_RhB@Q[7]A plot of fluorescence intensity;

FIG. 13 is Ba²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺For H33342@2Q [7]]Fluorescence spectra of (10. mu.M) titration, inset: N_M ⁿ⁺/N_H33342@2Q[7]A plot of fluorescence intensity;

FIG. 14 is Ba²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺For BER @ Q [7]]Fluorescence spectra of (10. mu.M) titration, inset: N_Mn+/N_BER@Q[7]A plot of fluorescence intensity;

Detailed Description

The present invention will be described in further detail with reference to specific examples. The experimental procedures used below are, unless otherwise specified, all conventional procedures known in the art and the ingredients or materials used, if not specified, are all commercially available ingredients or materials. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention.

Example 1, a supramolecular fluorescence sensing array and method for detecting multiple metal ions in an aqueous solution. The method specifically comprises the following steps:

1. preparation of RhB @ Q7 supramolecular fluorescent probe standard solution

1) Taking Q [7]]134.2mg dissolved in ultrapure water, sonicated, transferred to a 100mL volumetric flask to give solution A having a concentration of 1X 10^-3mol/L for standby;

2) dissolving RhB 47.9mg in water, transferring into 100mL volumetric flask, and diluting with ultrapure water to desired volume to obtain solution B with concentration of 1 × 10^-3mol/L for standby;

3) mixing the solution A and the solution B at a volume ratio of 1:1 (i.e. a molar ratio of 1:1) to obtain a mixture with a concentration of 1 × 10^-3mol/L probe solution, diluted with water to 1X 10 if necessary^-5mol/L to obtain RhB @ Q [7]]Supramolecular fluorescent probes.

2. Preparation of H33342@2Q 7 supramolecular fluorescent probe standard solution

1) Taking Q [7]]134.2mg dissolved in water, sonicated, transferred to a 100mL volumetric flask to give solution A at a concentration of 1X 10^-3mol/L for standby;

2) dissolving H3334256.2mg in water, transferring into 100mL volumetric flask, and diluting with water to desired volume to obtain solution C with concentration of 1 × 10^-3mol/L for standby;

3) mixing the solution A and solution C at a volume ratio of 2:1 (i.e. a molar ratio of 2:1) to obtain a mixture with a concentration of 1 × 10^-3mol/L probe solution, diluted with water to 1X 10 if necessary^-5mol/L to obtain H33342@2Q [7]Supramolecular fluorescent probes.

3. Preparation of BER @ Q7 supermolecule fluorescent probe standard solution

1) Taking Q [7]]134.2mg dissolved in water, sonicated, transferred to a 100mL volumetric flask to give solution A at a concentration of 1X 10^-3mol/L for standby;

2) dissolving BER 40.8mg in water, transferring into 100mL volumetric flask, and diluting to constant volume with water to obtain solution D with concentration of 1 × 10^-3mol/L for standby;

3) mixing the solution A and solution D at a volume ratio of 1:1 (molar ratio of 1:1) to obtain a mixture with a concentration of 1 × 10^-3mol/L probe solution, diluted with water to 1X 10 if necessary^-5mol/L to obtain BER @ Q7]Supramolecular fluorescent probes.

4. Preparing a metal ion standard solution:

accurately weighing the required metal ion Ba²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr²⁺(perchlorate) analytical grade, dissolved in water to give a 2X 10 molar concentration^-1mol/L of each metal ion standard solution.

5. And (3) qualitative analysis:

1) adding the standard solution of different metal ions (molar ratio of the supermolecule fluorescent probe to each metal ion is 1:50) obtained in step 4 into the solution of RhB @ Q7 supermolecule fluorescent probe obtained in step 1, standing for 20min, respectively performing fluorescence emission spectrometry on the solution and observing the change of fluorescence color under a 365nm ultraviolet lamp:

RhB@Q[7]the supramolecular fluorescent probe is bright yellow fluorescence. If the fluorescence emission at about 588nm is slightly reduced and the color of the fluorescence observed under an ultraviolet lamp is almost unchanged, this indicates that the metal ion is Fe²Or Al³⁺(ii) a If the fluorescence emission at 588nm is obviously reduced and the fluorescence color is changed from yellow to darker yellow, the metal ion is Hg²⁺Or Cr³⁺And Hg is the orange color of the fluorescent material²⁺The dark yellow is Cr³⁺(ii) a If the fluorescence emission at 588nm is reduced to a greater extent and the fluorescence changes from yellow to darker yellow when viewed under an ultraviolet lamp, this indicates that the metal ion is Ba²⁺Or Pb²⁺(ii) a If the fluorescence intensity at 588nm is reduced to the maximum extent and the fluorescence color is almost completely darkened when observed under an ultraviolet lamp, the metal ion is Fe³⁺。

2) Adding the standard solution of different metal ions obtained in step 4 into the H33342@2Q 7 supramolecular fluorescent probe solution obtained in step 2 (the molar ratio of the supramolecular fluorescent probe to each metal ion is 1:50) standing for 20min, and comparing the change of the fluorescence intensity with the change of the fluorescence color under a 365nm ultraviolet lamp:

H33342@2Q[7]the supramolecular fluorescent probe itself is bright bluish fluorescence. If the maximum emission at 582nm is only slightly reduced and the fluorescence color is hardly changed compared with the probe, the metal ion is Al³⁺And Cr³⁺(ii) a If the probe had a complete quenching of the fluorescence emission at 582nm and a complete darkening of the fluorescence color under UV light, this would indicate that the metal ion was Hg²⁺(ii) a If the maximum emission at 582nm is quenched to a degree of less than Hg only²⁺When the fluorescent color under the ultraviolet lamp is changed from cyan to dark green, the metal ion is Fe²⁺And Fe³⁺And more varied is Fe³⁺(ii) a If the maximum emission at 582nm is slightly reduced with the blue shift phenomenon and the fluorescent color is changed from bluish to sky-blue under a 365nm ultraviolet lamp, it indicates that the metal ion is Ba²⁺And Pb²⁺。

3) Adding the standard solution of different metal ions obtained in step 4 into the BER @ Q7 supramolecular fluorescent probe solution obtained in step 3 (the molar ratio of the supramolecular fluorescent probe to each metal ion is 1:50) Standing for 20min, and comparing the change of the fluorescence intensity with the change of the fluorescence color under a 365nm ultraviolet lamp:

BER@Q[7]the supramolecular fluorescent probe is bright green fluorescence. If the fluorescence emission intensity at about 500nm is almost unchanged and the fluorescence color is also almost unchanged compared with the probe, it indicates that the metal ion is Al³⁺，Cr³⁺And Hg²⁺(ii) a If the fluorescence emission at about 500nm is significantly reduced and the fluorescence color changes from bright green to dark green compared to the probe, it indicates that the metal ion is Pb²⁺And Ba²⁺And Fe²⁺(ii) a If the fluorescence emission at about 500nm is maximally reduced and the fluorescence color is almost completely darkened compared to the probe, it indicates that the metal ion is Fe³⁺。

4) Separately adding RhB @ Q [7] obtained in 1), 2) and 3)]、H33342@Q[7]And BER @ Q [7]]The fluorescent color under 365nm ultraviolet lamp irradiation is taken color to design a fluorescent color array of 3 sensing elements multiplied by 7 metal ions, so that the array pair Ba can be obviously found²⁺,Hg²⁺, Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺The responses of the 7 metal ions are remarkably different, and the purpose of well distinguishing the 7 metal ions can be achieved through the contrast of the matrix fluorescence colors, as shown in fig. 3.

6. Statistical data analysis

1) Preparation of RhB @ Q [7] in ultrapure water](10μM)、H33342@2Q[7](10. mu.M) and BER @ Q [7]](10. mu.M) of the three supramolecular fluorescent probes, using a 96-well all-black sterile microtiter plate, 300. mu.L of each of the three probes (each 10. mu.M in concentration) and Ba were added to each well²⁺,Hg²⁺, Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺Mixed sample solutions of these 7 metal ions (500 μ M, 50 times the concentration of the probe) were run in parallel with five sets of data for each mixed sample. And detecting the fluorescence spectrum and the maximum emission fluorescence intensity of the mixed sample on the 96-hole microtiter plate on a full-function microplate detector in sequence. It generates a data matrix consisting of 3 sensing elements × 7 metal ions × 5 parallel experiments, and then performs Linear Discriminant Analysis (LDA) on the data matrix using SPSS version 22.0:

in the LDA model diagram, the region at the upper left corner is Ba²⁺And Pb²⁺(ii) a At the lower left corner is Fe³⁺(ii) a In the middle region is Fe²⁺(ii) a In the upper right corner region is Al³⁺,Cr³⁺(ii) a In the lower right corner region is Hg²⁺. As can be seen from the data results, the sensor array can realize the Ba-alignment to a certain extent²⁺,Hg²⁺,Fe²⁺, Fe³⁺,Pb²⁺,Al³⁺,Cr³⁺Detection and identification of these 7 metal ions.

2) Using the method described in 1), Pb was selected in this example²⁺As model analytes, 7 different Pb were determined²⁺The fluorescence response at a concentration (0. mu.M, 100. mu.M … … 500. mu.M) gave a signal consisting of 3 sensor elements X6 Pb species²⁺Concentration x 5 data matrix of parallel experiments and data analysis with LDA:

pb in the top left corner region of the LDA model diagram²⁺Concentrations of 500 and 600. mu.M; pb in the bottom region²⁺Concentrations of 200,300 and 400. mu.M and unknown concentrations (actually 200. mu.M); pb in the upper right region²⁺The concentration is 100 MuM; located in the lower right-hand corner region is a blank control sample. As can be seen from the data results, the sensing array can detect different metal ions to a certain extent (FIG. 5).

In order to obtain the scheme and verify the technical effect of the invention, the inventor conducts a large number of experiments, and partial experiments are recorded as follows:

experimental case 1: the invention relates to a preparation method of each reagent in the analysis method.

1) Preparation of Q7, RhB, H33342, BER standard solution

Q[7]: taking Q [7]]134.2mg dissolved in ultrapure water, sonicated, transferred to a 100mL volumetric flask to give solution A having a concentration of 1X 10^-3mol/L for standby;

RhB: dissolving RhB 47.9mg in water, transferring into 100mL volumetric flask, and diluting with ultrapure water to desired volume to obtain solution B with concentration of 1 × 10^-3mol/L for standby;

h33342: dissolving H3334256.2mg in water, transferring into 100mL volumetric flask, and diluting with water to desired volume to obtain solution C with concentration of 1 × 10^-3mol/L for standby;

BER: dissolving BER 40.8mg in water, transferring into 100mL volumetric flask, and diluting to constant volume with water to obtain solution D with concentration of 1 × 10^-3mol/L for standby;

2) preparing a metal ion standard solution:

accurately weighing the required metal ion Ba²⁺,Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al³⁺,Cr²⁺(perchlorate) analytical grade, dissolved in water to give a 2X 10 molar concentration^-1mol/L of each metal ion standard solution.

The implementation case is that 2: three supramolecular fluorescent probes RhB @ Q7, H33342@2Q 7 and BER @ Q7 are prepared.

1) In order to determine the action ratio of Q7 to probe formed by RhB, H33342 and BER, the inventor adopts a molar ratio method to respectively measure the ultraviolet absorption, fluorescence emission and the like, and researches the interaction between Q7 and RhB, H33342 and BER; and further determining the action ratio between Q7 and the three guest molecules by using Job's method.

For example: diluting the solution B (RhB) obtained in step 1 with water to 1X 10^-5Determining the ultraviolet visible absorption spectrum of the product by mol/L by a molar ratio method; the fixed excitation wavelength is 550nm, the voltage is 430V, the excitation and emission slit is 5nm, and the fluorescence emission spectrum is measured by a molar ratio method. In RhB pure water, there is characteristic fluorescence emission peak at 584nm when RhB and Q [7]]After complex formation, fluorescence is significantly enhanced. FIG. 6 shows RhB and Q [7] in aqueous solution]UV absorption and fluorescence emission spectra of action when RhB (10. mu.M) is gradually added to Q7 in aqueous solution](0-30. mu.M), the fluorescence intensity of the system is increased, and the ultraviolet absorption intensity at the wavelength of 553nm is also changed with Q7]The addition of (5) is slightly red shifted to 555 nm. Subjecting the solution A (Q7) obtained in step 1]) Diluting with solution B (H33342) with water, and fixing Q7]The total concentration of H33342 is 1X 10^-5mol/L, and the fluorescence emission was measured by Job's method (the fluorescence conditions were the same as those described above). From 584nm N_RhB/N_Q[7]The relationship between the fluorescence intensity and the Job method shows that RhB and Q7]The action ratio of (A) to (B) is 1: 1. Therefore, a volume ratio of 1:1 (i.e. molar ratio 1:1) solution A from step 1 was mixed with solution B and diluted to 1X 10 with water^-5mol/L, namely the concentration is 1 multiplied by 10^-5mol/L of RhB @ Q [7]]Supramolecular fluorescent probe solution.

Q[7]Reference Q7 for the interaction with H33342 and BER]Experimental methods with RhB. Wherein: when a fluorescence emission spectrum is tested, the excitation wavelength of H33342 is 352nm, the voltage is 410V, and the slits are all 5 nm; the BER excitation wavelength is 353nm, the voltage is 485V, and the slits are all 5 nm. Found Q7]The action ratio of the compound to H33342 is 1:2 (FIG. 7), Q7]The mode of action with BER is 1:1 (fig. 8). Then, the concentrations of 1X 10 can be obtained^-5mol/L of H3334@2Q [7]]Supramolecular fluorescent probe solution and concentration of 1 × 10^-5BER @ Q7 of mol/L]Supramolecular fluorescent probe solution.

Example 3: qualitative analysis of 7 kinds of metal ions by RhB @ Q7, H33342@2Q 7 and BER @ Q7

To RhB @ Q [7] prepared in Experimental example 1]、H33342@2Q[7]And BER @ Q [7]]Adding the standard solutions of different metal ions (the molar ratio of the supramolecular fluorescent probe to each metal ion is 1:50) obtained in the step (4) into the 3 supramolecular probe solutions (all are 10 mu M), standing for 20min, and respectively carrying out fluorescence emission spectrometry on the solutions, wherein when the fluorescence emission spectra are measured by observing the fluorescence color under a 365nm ultraviolet lamp, the excitation wavelength of H33342 is 352nm, the voltage is 410V, and the slits are all 5 nm; the RhB excitation wavelength is 550nm, the voltage is 430V, and the slits are all 5 nm; the BER excitation wavelength is 353nm, the voltage is 485V, and the slits are all 5 nm. The results show that: for RhB @ Q [7]]For the fluorescence response degree: fe³⁺＞Ba²⁺＝ Pb²⁺＞Hg²⁺＞Cr³⁺＞Fe²⁺＞Al³⁺As shown in fig. 1(a, b). Fe³⁺Can reduce the fluorescence intensity of the system to the maximum, Ba²⁺Or Pb²⁺Is only weaker than Fe³⁺And secondly Cr³⁺Then is Fe²⁺，Al³⁺The addition of (A) does not cause the fluorescence intensity of the system to change obviously; for H33342@2Q [7]]The response degree is: hg is a mercury vapor^{2 +}＞Fe³⁺＞Fe²⁺＞Cr³⁺＞Al³⁺＞Pb²⁺＞Ba²⁺(FIG. 1(c, d)). Hg is a mercury vapor²⁺Can reduce the fluorescence intensity of the system to the maximum and almost completely quench, Fe³⁺Is only weak than Hg²⁺And secondly Fe²⁺Then is Cr³⁺And Al³⁺，Pb²⁺And Ba²⁺Although the addition of (2) only slightly reduces the fluorescence intensity of the system, the fluorescence emission has obvious blue shift phenomenon; for BER @ Q [7]]For example, the degree of response is: fe³⁺＞Fe²⁺＞Ba²⁺＝Pb²⁺＞Hg²⁺＞Cr³⁺＞Al³⁺(FIG. 1(e, f)). Fe³⁺Can reduce the fluorescence intensity of the system to the maximum, Fe²⁺Is only reduced less than Fe³⁺And secondly is Ba²⁺And Pb²⁺Then Hg²⁺And Cr³⁺，Al³⁺The addition of (A) does not cause a significant change in the fluorescence intensity of the system.

The respective addition of the above-mentioned 7 metal ions to Rh was observed at 365nmB@Q[7]、 H33342@2Q[7]And BER @ Q [7]]The case of a color change is shown in fig. 2. For RhB @ Q [7]]In (2(a)), the probe itself is bright yellow, Fe³⁺Can almost completely quench fluorescence; ba²⁺Or Pb²⁺So that the fluorescence of the system is quenched only if the system is Fe³⁺The fluorescence color is also dark yellow; followed by Hg²⁺Or Cr³⁺Fluorescence reduction ratio Ba²⁺Or Pb²⁺Slightly lighter, the fluorescent color is brighter yellow; and Fe²⁺Or Al³⁺The fluorescence reduction of the system is not obvious and is not greatly different from that of the probe. For H33342@2Q [7]]In contrast (FIG. 2(b)), the probe itself fluoresces bright cyan in water under a 365nm UV lamp, and the fluorescence is very strong. Hg is a mercury vapor²⁺The addition of (a) can completely quench the system fluorescence, and no fluorescence can be observed at the same time; fe²⁺And Fe³⁺The addition of (2) can obviously weaken the fluorescence of the system, and the color is obviously changed from cyan to dark green; ba²⁺And Pb²⁺Changing the fluorescent color of the system from bright cyan to bright blue; al (Al)³⁺And Cr³⁺No significant change in the color of the system occurs. For BER @ Q [7]](FIG. 2(c)) the probe itself is green, Fe³⁺The system fluorescence can be changed into dark green; fe²⁺The degree of darkening the fluorescence color of the system is only less than that of Fe³⁺；Ba²⁺And Pb²⁺Can also darken the fluorescent color of the system, but the degree is not higher than that of Fe³⁺And Fe²⁺(ii) a And Hg²⁺、Cr³⁺Or Al³⁺The change degree of the fluorescence color of the system is very weak, and the fluorescence color is not obviously different from the fluorescence color of the probe.

Example 4: statistical analysis of 7 metal ions by RhB @ Q7, H33342@2Q 7 and BER @ Q7 supramolecular fluorescent probes

1) Array experiments were performed on 96-well all-black sterile microtiter plates. Add 300. mu.L of RhB @ Q [7] to each well separately](10μM、H33342@2Q[7](10μM)、BER@Q[7](10. mu.M) and metal ions (500. mu.M), and each mixed sample was replicated in parallel with five sets of data. And respectively detecting the fluorescence spectrum and the maximum emission fluorescence intensity of the sample on the 96-hole microtiter plate on a full-function microplate detector.It produced a data matrix consisting of 3 sensing systems x 7 metal ions x 5 replicates, which was subjected to Linear Discriminant Analysis (LDA) using SPSS version 22.0, as shown in fig. 4. The results show that: this sensing array can correctly classify 91.4% of the metal ions (table 1). Ba²⁺, Hg²⁺,Fe²⁺,Fe³⁺,Pb²⁺,Al^{3 +},Cr³⁺The 7 metal ions have very obvious discrimination under an LDA discrimination model established by utilizing a Fisher function, so that the sensing array can qualitatively identify and distinguish the 7 metal ions. Analysis revealed that Ba was the major cause of the error²⁺And Pb²⁺Has two Pb²⁺Is misjudged as Ba²⁺One of Ba²⁺The data is misjudged as Pb²⁺So Ba in the sensor array²⁺And Pb²⁺There will be some mutual interference between them.

2) Respectively adding 300 mu L of Pb with different concentration gradients on a 96-well plate²⁺(0mol·L ^-1100 μ M, 200 μ M, 300 μ M, 400 μ M, 500 μ M, 600 μ M + an unknown concentration (actually 200 μ M)), with RhB @ Q [7]](10μM)、H33342@2Q[7](10. mu.M) and BER @ Q [7]](10 μ M) of mixed samples, each mixed sample paralleling five sets of data. Respectively detecting the samples on a full-function micropore plate detector to obtain 3 sensing systems X6 Pb²⁺Concentration x 5 replicates of a data matrix that was subjected to Linear Discriminant Analysis (LDA) using SPSS version 22.0, as shown in fig. 5. The results show that: the array was able to correctly align to 97.1% Pb²⁺The concentration data were classified (table 2). Different Pb²⁺The concentration has very obvious discrimination under an LDA discrimination model established by utilizing a Fisher function, so that the sensing array can qualitatively identify and discriminate 7 metal ions; and the array was able to successfully discriminate all 4 of the unknown data to a concentration range of 200 μ M. These results are encouraging and further demonstrate the versatility of the sensor array to enable quantitative detection and identification of metal ions.

Table 1 LDA classification of different metal ions by sensor array in ultrapure water (leave-one-out cross-validation, misclassified data followed by (×))

TABLE 2 Induction array in ultrapure water for different concentrations of Pb²⁺LDA classification (red indicates classification error)

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims (8)

1. A supramolecular fluorescence sensing array for detecting various metal ions in an aqueous solution is characterized in that: the supermolecule fluorescence sensing array comprises three supermolecule fluorescence probes of RhB @ Q7, H33342@2Q 7 and BER @ Q7.

2. The supramolecular fluorescence sensing array for detecting multiple metal ions in aqueous solution as claimed in claim 1, wherein: the RhB @ Q7 supramolecular fluorescent probe is prepared by mixing a Q7 solution and a RhB solution in a molar ratio of 1: 1.

3. The supramolecular fluorescence sensing array for detecting multiple metal ions in aqueous solution as claimed in claim 1, wherein: the H33342@2Q 7 supramolecular fluorescent probe is prepared by mixing a Q7 solution and an H33342 solution in a molar ratio of 2: 1.

4. The supramolecular fluorescence sensing array for detecting multiple metal ions in aqueous solution as claimed in claim 1, wherein: the BER @ Q7 supramolecular fluorescent probe is prepared by mixing a Q7 solution and a BER solution in a molar ratio of 1: 1.

5. The supramolecular fluorescence sensing array for detecting multiple metal ions in aqueous solution as claimed in claim 1, wherein: the RhB @ Q [7]]、H33342@2Q[7]And BER @ Q [7]]The concentration of three supramolecular fluorescent probes is 1 multiplied by 10^{- 5}mol/L of RhB @ Q [7]]Supramolecular fluorescent probes.

6. A method for detecting a plurality of metal ions in an aqueous solution, comprising: the method comprises the following steps:

(1) formulating a set of supramolecular fluorescence sensing arrays according to any one of claims 1 to 5;

(2) prepare a group of Ba²⁺、Hg²⁺、Fe²⁺、Fe³⁺、Pb²⁺、Al³⁺And Cr²⁺A metal ion standard solution;

(3) each metal ion standard solution is respectively added into a supermolecule fluorescence sensing array to obtain a mixed sample solution, a group of data is obtained by detecting the fluorescence spectrum and the maximum emission fluorescence intensity of the mixed sample solution, and a data matrix consisting of 3 sensing elements, 7 metal ions and 5 parallel experiments is obtained by performing more than 2 parallel experiments;

(4) analyzing the data matrix by software to obtain a standard model;

(5) providing 3 parts of aqueous solution to be detected, respectively adding into three kinds of supermolecule fluorescent probes of RhB @ Q7, H33342@2Q 7 and BER @ Q7, detecting fluorescence spectrum and maximum emission fluorescence intensity, inputting the detected value into a standard model to obtain a detection result.

7. The method of claim 6, wherein the step of detecting the plurality of metal ions in the aqueous solution comprises: in the step (2), the concentration of the metal ion standard solution is 50 times of that of the supramolecular fluorescent probe.

8. The method of claim 6, wherein the step of detecting the plurality of metal ions in the aqueous solution comprises: the step (4) is as follows: performing linear discriminant analysis on the data matrix by using SPSS software to obtain a standard model; the standard model is the LDA model.

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