阅读说明：本技术 一种可动态检测水中Fe3+及Al3+分子探针及应用 (Can dynamic detection aquatic Fe3+And Al3+Molecular probe and application ) 是由 陈玉婷 李洪亮 王芳 杜鹏 胡慧 范晋勇 张严严 刘世楷 于 2021-09-28 设计创作，主要内容包括：本发明提供了一种可动态检测水中Fe～(3+)及Al～(3+)分子探针及应用,涉及有机化合物检测性能技术领域。本发明提供的分子探针是以2,3-二羟基苯甲醛和2,7二氨基芴为反应原料,通过一步聚合反应制备。由于该分子探针同时含有亚胺、邻二羟基三个金属离子作用位点,对Al～(3+)呈现出显著的“关-开”荧光检测响应；对不同浓度Fe～(3+)表现出“关-开-关”双重荧光检测信号,对Fe～(3+)具有灵敏的定量检测性能,具有显著的应用价值；且其制备方法具有产率高、制备工艺简单,易于实施等优点,适合工业化推广,为本氨基芴希夫碱分子探针的推广应用创造了有利条件。(The invention provides a method for dynamically detecting Fe in water 3+ And Al 3+ A molecular probe and application thereof relate to the technical field of organic compound detection performance. The molecular probe provided by the invention is prepared by taking 2, 3-dihydroxy benzaldehyde and 2, 7-diaminofluorene as reaction raw materials through one-step polymerization reaction. Because the molecular probe simultaneously contains three metal ion action sites of imine and o-dihydroxy, Al is reacted 3+ Exhibits a significant "off-on" fluorescence detection response; for different concentrations of Fe 3+ Exhibits an "off-on-off" dual fluorescence detection signal for Fe 3+ The kit has sensitive quantitative detection performance and obvious application value; and a process for the preparation thereofThe method has the advantages of high yield, simple preparation process, easy implementation and the like, is suitable for industrial popularization, and creates favorable conditions for the popularization and application of the aminofluorene Schiff base molecular probe.)

1. Can dynamic detection aquatic Fe³⁺And Al³⁺The molecular probe of (1), which has a molecular structure of:

。

2. the method of claim 1 for dynamically detecting Fe in water³⁺And Al³⁺The molecular probe is characterized in that a receptor unit simultaneously contains three metal ion action sites of imine and ortho-dihydroxy; for Al³⁺Exhibits a significant "off-on" fluorescence detection response; for different concentrations of Fe³⁺Exhibits an "off-on-off" dual fluorescence detection signal for Fe³⁺Has sensitive quantitative detection performance.

Technical Field

The invention relates to the technical field of organic compound detection performance, in particular to a method for detecting Fe in water³⁺、Al³⁺An aminofluorene Schiff base molecular probe with sensitive off-on-off and off-on fluorescence detection signals and application thereof.

Background

With the social development, the problem of environmental pollution is a hot spot of global common attention, and is also one of the main problems faced by the sustainable development of economy and society in China. Metals such as iron, aluminum, etc. have wide application in current industrial production. However, when they are discharged in a cationic form to the nature along with industrial wastewater, they cause serious pollution to the whole water system, causing great harm to the ecosystem and human living environment. In particular, metal ions discharged into the ecological environment are hardly degraded, and they are easily enriched and expanded in the biological chain. Once the water and food polluted by metal are eaten by people, metal ions can be continuously accumulated in the human body, and serious harm is caused to the human body. For example, iron is one of the essential trace elements of human body, but excessive iron ions in the body can cause abnormal liver function, myocardial damage, diabetes, tumor, osteoporosis and the like; accumulation of aluminum in the brain can cause cerebral neurodegeneration, memory deterioration, and even the manifestation of senile dementia, etc. Therefore, the development of a method for sensitively and rapidly detecting metal ions in water has very important significance in the fields of chemistry and chemical industry, industrial and agricultural production, environmental science and the like.

Among many methods for analyzing and detecting metal ions, fluorescent molecular probes have become one of the hot spots of research due to their characteristics of high sensitivity, low cost, easy operation, etc. The fluorescent molecular probe converts identification information generated in the microscopic world into an optical signal easy to detect on the basis of molecular identification, is generally dispersed in a detected system in an independent molecular state and sends a detection signal, realizes in-situ and real-time detection on a single molecular level, and has sensitive and accurate analysis results. Based on different detection requirements, a large number of Fe detection reagents have been prepared³⁺、Al³⁺And the like. However, most of the existing fluorescent molecular probes only have a sensitive detection function on a certain specific metal ion, and the function is single; and reported Fe³⁺The fluorescent molecular probe mostly changes with the concentration, the fluorescence intensity signal only shows single increase or decrease, and the fluorescence signal is changed with Fe³⁺Few reports have been reported for sensitive molecular probes that exhibit a "off-on-off" bi-directional change in concentration. While to Fe in human practical work³⁺The need for dynamic change in concentration detection is increasing. Therefore, the development of sensitive, easy-to-prepare and dynamic Fe detection³⁺The fluorescent molecular probe is urgently needed in various monitoring fields at present.

In the construction process of the fluorescent molecular probe, the structural characteristic that metal ions are easy to coordinate is combined, groups containing N, O, S atoms with strong coordination capacity and the like are generally selected as metal ion binding sites when an ion receptor is designed, the metal ion binding sites are connected with fluorescent signal groups in a specific connection mode, microscopic identification information of the metal ions is converted into spectroscopic signals which are easy to test, and the fluorescent molecular probe with metal ion detection performance is obtained. The rigidly conjugated fluorene group has the characteristics of higher light stability, easy modification of structure and the like, and is an excellent fluorescent signal group. An imine Schiff base (-C = N-) group easy to synthesize has stronger metal coordination capacity, and the introduction of the group into a fluorescent molecule can increase the metal ion-metal coordination capacity between the molecule and metal ionsComplexation and selectivity of (a); and the conjugation of the fluorescent molecule can be increased by the p-pi conjugation effect after the-C = N-group is connected with the fluorophore, and when a nitrogen atom in the-C = N-group is coordinated with a heavy metal ion, the conjugation degree of the fluorescent molecule can be changed, so that the fluorescent molecule can show sensitive spectral signal change. After combining the two, a series of fluorescent molecular probes with different identification performances are prepared [ A. Hens, A. Maity, K.K. Rajak,Inorg. Chim. Acta,2014, 423, 408; J. Zhang, Z. Zhao, H. Shang, Q. Liu, F. Liu, New J. Chem., 2019, 43, 14179; F. Wang, C. Li, X. Zhang,A. Wang,L. Zhou,C. Jia,J. Xu, Y. Chen, Dyes and Pigments, 2019, 171, 107667]. But for Fe³⁺、Al³⁺Multifunctional fluorene schiff base fluorescent molecular probes with sensitive off-on-off and off-on fluorescent detection signals have not been reported.

Disclosure of Invention

The invention aims to provide a method for treating Fe in water³⁺、Al³⁺The multifunctional fluorescent molecular probe has sensitive 'off-on-off' and 'off-on' fluorescent detection signals respectively.

Another technical purpose of the invention is to provide a method for dynamically detecting Fe in water for people to work and live³⁺And Al³⁺The method has the advantages of rapidness, sensitivity, easy operation, low cost, easy popularization and the like.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

can dynamic detection aquatic Fe³⁺And Al³⁺The aminofluorene Schiff base fluorescent molecular probe has a molecular structure as follows:

can dynamic detection aquatic Fe³⁺And Al³⁺The preparation method of the aminofluorene Schiff base fluorescent molecular probe comprises the following steps:

placing alpha mmol of 2, 3-dihydroxy benzaldehyde into a round-bottom flask containing beta mL of absolute ethyl alcohol, and heating to reflux; then adding gamma mmol 2,7 diaminofluorene and continuing to react for 3-5 hours; filtering a mixture obtained by the reaction, washing with absolute ethyl alcohol, and drying to obtain a deep red aminofluorene Schiff base fluorescent molecular probe; the ratio of alpha, beta and gamma is 2:20: 1.

Can dynamic detection aquatic Fe³⁺And Al³⁺The preparation reaction formula of the aminofluorene Schiff base fluorescent molecular probe is as follows:

the invention has the following technical effects: the aminofluorene Schiff base fluorescent molecular probe receptor unit simultaneously contains three metal ion action sites of imine and ortho-dihydroxy; with Fe in solution³⁺The concentration is increased continuously, the maximum fluorescence emission of the molecule at the position of 410 nm is obviously enhanced and then reduced, and a sensitive 'off-on-off' dual fluorescence detection signal is presented for Fe³⁺The kit has sensitive quantitative detection performance; with Al in the solution³⁺The concentration is increased continuously, the maximum fluorescence emission intensity of the molecule at the position of 410 nm is obviously increased, multiple detection functions are endowed, and the application value is high; the preparation process of the aminofluorene Schiff base fluorescent molecular probe provided by the invention has the advantages of simple preparation process, mild reaction conditions, high yield and the like, is suitable for industrial implementation, and creates favorable conditions for popularization and application of the aminofluorene Schiff base fluorescent molecular probe.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of the compound obtained in example 1-2.

FIG. 2 shows fluorescence emission spectra of aminofluorene Schiff base fluorescent molecular probe added with different metal ions in 95% DMF aqueous solution.

FIG. 3 shows that the aminofluorene Schiff base fluorescent molecular probe is added with Fe with different concentrations in 95% DMF aqueous solution³⁺Fluorescence emission spectrum of (1).

FIG. 4 shows that the aminofluorene Schiff base fluorescent molecular probe is added with Al with different concentrations in 95% DMF aqueous solution³⁺Fluorescence emission spectrum of (1).

FIG. 5 shows aminofluorene Schiff base fluorescenceAdding 10 times of Fe into 95% DMF aqueous solution by using molecular probe³⁺And fluorescence emission spectra of other different metal ions.

Detailed Description

The invention discloses a method capable of dynamically detecting Fe in water³⁺And Al³⁺The aminofluorene Schiff base fluorescent molecular probe has a molecular structure as follows:

；

the catalyst can be prepared by adopting 2, 3-dihydroxy benzaldehyde and 2, 7-diaminofluorene as reaction raw materials through one-step polymerization reaction, and the preparation reaction formula is as follows:

。

example 1

2 mmol of 2, 3-dihydroxy benzaldehyde is put into a round-bottom flask containing 20 mL of absolute ethyl alcohol, and then the temperature is raised to reflux; then 1 mmol of 2,7 diaminofluorene is added and the reaction is continued for 3 hours; and filtering, washing with absolute ethyl alcohol and drying the mixture obtained in the reaction to obtain a crimson aminofluorene Schiff base fluorescent molecular probe A, 235.4 mg, with the yield of 54%.

Example 2

2 mmol of 2, 3-dihydroxy benzaldehyde is put into a round-bottom flask containing 20 mL of absolute ethyl alcohol, and then the temperature is raised to reflux; then 1 mmol of 2,7 diaminofluorene is added to continue the reaction for 5 hours; and filtering, washing with absolute ethyl alcohol and drying the mixture obtained in the reaction to obtain a dark red aminofluorene Schiff base fluorescent molecular probe B, 236 mg and 54% of yield.

The analysis of the compounds A and B obtained in examples 1-2, respectively, showed that the nuclear magnetic hydrogen spectra were consistent, and the data were as follows: in that¹H NMR (DMSO-d₆400 MHz), contains 4 OH proton signal peaks: 13.79 (s, 2H), 9.75 (s, 2H); 2 proton signal peaks on C = N-carbon: 8.90 (s, 2H); 12 aromatic ring proton signal peaks: 8.51 (s, 2H), 7.97 (d, 2H), 7.64 (s, 4H), 7.44 (d, 2H), 6.99 (d, 2H), 6.46 (d, 2H); 2 fluorenyl radicalGroup CH₂-proton signal peak: 4.02 (s, 2H), which is basically consistent with the fluorescent molecular theoretical value of aminofluorene Schiff base. From this, it was confirmed that compound A, B has the following molecular structure:

namely, aminofluorene Schiff base fluorescent molecules.

Example 3

The fluorescence detection performance of aminofluorene Schiff base fluorescent molecules on different metal ions in 95% DMF aqueous solution is as follows: in 95% DMF aqueous solution, concentration 2X 10^-5The mol/L aminofluorene Schiff base fluorescent molecule has a weak fluorescence emission peak near the position of 410 nm; adding 10 times of mol equivalent of Fe³⁺Then, the maximum fluorescence emission intensity at the 410 nm position is increased by 2.4 times, and blue-shifted to the vicinity of the 405 nm position; 10 times molar equivalent of Al³⁺After the probe molecule is added, the maximum fluorescence emission blue of the probe molecule is shifted to be near the position of 403 nm, and the fluorescence intensity is increased by 17.8 times; other metal ions, e.g. Li⁺、Na⁺、K⁺、Ba²⁺、Ca²⁺、Mg²⁺、Ag⁺、Co^{2 +}、Hg²⁺、Mn²⁺、Ni²⁺、Cd²⁺、Zn²⁺After the addition of the plasma metal ions, the maximum fluorescence emission of the compound at the position of 410 nm is changed slightly. These show that aminofluorene schiff base fluorescent molecule pairs Fe³⁺、Al³⁺The ions have different fluorescence detection responses.

Example 4

Aminofluorene Schiff base fluorescent molecule in 95% DMF water solution for different concentrations of Fe³⁺Fluorescence detection performance of (2): at a concentration of 2X 10^-5Fe with different concentrations is respectively added into 95 percent DMF aqueous solution of mol/L aminofluorene Schiff base fluorescent molecules³⁺The molar equivalent ratio of the two is 1:0, 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.5, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 and 1:20 respectively. Detailed fluorescence emission spectroscopy data studies show that: with Fe in aqueous solution³⁺The amount of the substance is increased continuously from 0 to 3When the fluorescence intensity is multiplied, the maximum fluorescence emission of the aminofluorene Schiff base fluorescent molecule is remarkably enhanced near 410 nm, the maximum fluorescence emission is increased by 11 times, and the maximum fluorescence emission is slightly blue-shifted to a 405 nm position; continuing to increase Fe³⁺The amount of the substance is increased from 3 to 10 times, and the fluorescence emission intensity is obviously reduced; then continuing to increase Fe³⁺The fluorescence emission spectrum is basically unchanged when the amount of the substance is up to 20 times; shows that the aminofluorene Schiff base fluorescent molecular probe can treat Fe with different concentrations in 95 percent DMF aqueous solution³⁺Has dynamic 'off-on-off' double fluorescence signal detection potential.

Example 5

Aminofluorene Schiff base fluorescent molecule in 95% DMF water solution for Al with different concentrations³⁺Fluorescence detection performance of (2): at a concentration of 2X 10^-5Al with different concentrations is respectively added into 95 percent DMF aqueous solution of mol/L aminofluorene Schiff base fluorescent molecules³⁺The molar equivalent ratio of the two is 1:0, 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.5, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 and 1:20 respectively. The fluorescence emission spectrum property study of the system shows that: with Al in solution³⁺The concentration is increased continuously, when the molar equivalent is increased from 0 to 10 times, the maximum fluorescence emission intensity of aminofluorene Schiff base fluorescent molecules near 410 nm is obviously increased, and the aminofluorene Schiff base fluorescent molecules are blue-shifted to 403 nm; shows that the fluorescent molecules of aminofluorene Schiff base are aligned to Al in 95% DMF aqueous solution³⁺Has sensitive 'off-on' fluorescence signal detection potential.

Example 6

Fe of aminofluorene Schiff base fluorescent molecule in 95% DMF water solution³⁺Selective competitive properties with other metal ions: at a concentration of 2X 10^-5Respectively adding 10 times of molar equivalent Fe into 95% DMF aqueous solution of mol/L aminofluorene Schiff base fluorescent molecules³⁺And other different metal ions. The fluorescence emission spectrum research of the mixed system shows that: adding 10 times of molar equivalent Fe into aminofluorene Schiff base fluorescent molecules³⁺Then, it has a medium-intensity fluorescence emission near the 405 nm position; when reacting with Li⁺、Na⁺、K⁺、Ba²⁺、Ca²⁺、Mg²⁺、Ag⁺、Co²⁺、Hg²⁺、Mn²⁺、Ni²⁺、Cd²⁺、Zn²⁺、Al³⁺Adding aminofluorene Schiff base fluorescent molecules and Fe into metal ions³⁺After the system is mixed, the fluorescence emission spectrum of the mixed system is not changed very obviously, which shows that even Fe³⁺When coexisting with other metal ions, the aminofluorene Schiff base fluorescent molecule pair Fe³⁺Still exhibit good selective detection performance.

Example 7

Ultraviolet and fluorescent properties of different metal ions in 95% DMF aqueous solution: respectively adding Li into a mixed solvent of N, N-dimethylformamide and water with the volume ratio of 95:5⁺、Na⁺、K⁺、Ba²⁺、Ca²⁺、Mg²⁺、Ag⁺、Co²⁺、Hg²⁺、Mn²⁺、Ni²⁺、Cd²⁺、Zn²⁺、Al³⁺、Fe³⁺After the metal ions are subjected to plasma treatment, the fluorescence emission spectrum of the metal ions is not changed.