A method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect

Abstract

The present invention belongs to the technical field of electrochemiluminescence, and specifically discloses a method for identifying tyrosine enantiomers based on porphyrin MOF materials to enhance the electrochemiluminescence effect. Tetrakis(4-carboxyphenyl)porphyrin and metal ion zinc are prepared into a MOF structure, and chiral binaphthol is introduced to achieve chiral transfer, and the morphology of the material is regulated by a surfactant-assisted self-assembly method to obtain a nanoscale product tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly, which is modified on the electrode surface, enhances the electrochemiluminescence signal of L-tyrosine, and does not change the electrochemiluminescence signal of D-tyrosine, and realizes the identification of tyrosine enantiomers based on electrochemiluminescence.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemiluminescence, and particularly relates to a porphyrin-based MOF material and an application thereof to tyrosine enantiomer recognition. Background Art

[0002] Chirality is a common phenomenon in nature, and enantiomers of different configurations generally exhibit completely different biological activities. Amino acids are the molecular building blocks of living organisms and play a vital role in many related fields such as life systems. Therefore, the chiral recognition of amino acid enantiomers is of great significance in life sciences. Common chiral separation techniques include high performance liquid chromatography, gas chromatography, and capillary electrophoresis. However, most of these methods require expensive chiral columns and complex sample pretreatment processes and are not suitable for real-time analysis. Amino acids are the basic units of proteins and are important small molecules with two different configurations, L and D, which lead to different biochemical activities in physiological processes. Generally, L-amino acids have long been considered to be a single form in organisms, but recent studies have shown that there are multiple D-amino acids in mammalian tissues or body fluids and have important physiological functions. The absence of L-tyrosine (L-Tyr) may lead to albinism and alkaloids, while excessive concentrations of L-Tyr may lead to increased sister chromatid exchanges. Unlike L-Tyr, abnormally high levels of D-Tyr in plasma can be used as a monitoring indicator for chronic renal failure. Since the two configurations of tyrosine have different physiological activities, the recognition of tyrosine enantiomers is of practical significance. However, there are few reports on the recognition of tyrosine enantiomers by electrochemiluminescence in the prior art. Summary of the invention

[0003] The present invention aims to provide a porphyrin-based MOF material and its application to the identification of tyrosine enantiomers. The present invention constructs a new tetrakis(4-carboxyphenyl) / S-binaphthol / metal ion zinc electrochemiluminescence system, which has the advantages of simplicity, sensitivity and good selectivity for tyrosine enantiomers.

[0004] The present invention provides the following technical solutions:

[0005] A method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect, comprising the following steps:

[0006] (1) dissolving tetrakis(4-carboxyphenyl)porphyrin, S-binaphthol and zinc acetate in an aqueous solution containing sodium dodecylbenzene sulfate;

[0007] (2) mixing the S-binaphthol solution, the zinc acetate solution and the tetrakis(4-carboxyphenyl)porphyrin solution and stirring to react;

[0008] (3) After the reaction, centrifugation is performed, and the obtained solid is washed with ultrapure water and dried for 4-8 hours to obtain a chiral recognition material tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly.

[0009] (4) Dispersing the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly in step (3) in deionized water, applying the dispersed liquid droplets on the surface of the glassy carbon electrode, and drying at room temperature to obtain a glassy carbon electrode modified with the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly.

[0010] Particularly, in step (1), the molar ratio of tetrakis(4-carboxyphenyl)porphyrin to S-binaphthol and Zn is 1:(1-3):(1-4), and the volume ratio of tetrakis(4-carboxyphenyl)porphyrin solution, S-binaphthol solution and zinc acetate solution is 1:(1-1.5):(0-0.5);

[0011] Particularly, in step (2), the mixing method is to add the S-binaphthol solution and the zinc acetate solution dropwise into the tetrakis(4-phenyl, carboxyl)porphyrin solution, stirring in a water bath at 10-30° C., and reacting for 6-15 hours;

[0012] In particular, the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly is dispersed in deionized water, and the dispersion droplets are applied to the surface of the glassy carbon electrode and dried at room temperature to obtain a glassy carbon electrode modified with the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly; the concentration of the dispersed solution is 1-5 mg / mL, and the mass is 0.5-20 μg, preferably 10 μg.

[0013] Furthermore, a 10 mM ethanol solution of tetraoctylammonium bromide (TOAB) was prepared, and 5-15 μL of the TOAB ethanol solution was drop-coated on the electrode surface to enhance the electrode stability.

[0014] The application for the identification of tyrosine enantiomers is as follows:

[0015] A three-electrode system was formed by a glassy carbon electrode as a working electrode, a platinum wire as a counter electrode, and an Ag / AgCl electrode as a reference electrode. A glassy carbon electrode modified with tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly was used as the working electrode, a saturated calomel electrode was used as the reference electrode, a platinum sheet electrode was used as the counter electrode, N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) was used as the electrolyte, and hydrogen peroxide was used as a co-reactant. Cyclic voltammetry was performed using an electrochemical workstation, and the electrochemiluminescence intensity of the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly in HEPES electrolyte containing L / D-tyrosine was measured using an electrochemiluminescence instrument.

[0016] The voltage range of the cyclic voltammetry test is -1.5-0 V, the pH of the electrolyte HEPES is 4-9, preferably 8, and the amount of the co-reaction reagent hydrogen peroxide is 0-25 mM, preferably 15 mM.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The method for identifying tyrosine enantiomers based on the porphyrin MOF material enhanced electrochemiluminescence effect provided by the present invention is simple and easy to implement, and the prepared tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly has better electrochemiluminescence performance;

[0019] (2) Using micelles formed by surfactants to induce hydrophobic assembly units to enter the micelles, and further assemble through weak interactions between assembly unit molecules, thereby achieving controllable size and shape of self-assembled synthetic materials;

[0020] (3) The present invention uses a glassy carbon electrode modified with a tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly as a working electrode, and prepares a porphyrin ECL main material through tetrakis(4-carboxyphenyl)porphyrin, which can not only coordinate with metals, but also has variable functional groups at the end. The addition of chiral S-binaphthol and Zn allows the material to form a chiral MOF structure with excellent electrochemiluminescence performance, which plays a role in chiral recognition. L-tyrosine can be selectively recognized for binding and enrichment, which increases the electron transfer capacity of the electrode surface and produces a stronger ECL signal. However, D-tyrosine cannot be bound and enriched, so the tyrosine enantiomer can be identified by the intensity of electrochemiluminescence. The selective recognition of tyrosine enantiomers can be achieved, the results are reliable, and the operation method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Cyclic voltammograms of different materials in Example 1 with or without hydrogen peroxide;

[0022] Figure 2 The infrared spectra of TCPP, (S)-BINOL, TCPP-(S)-BINOL, and TCPP-Zn-(S)-BINOL assemblies in Example 1;

[0023] Figure 3 In Example 1, TCPP( Figure 3 A) TCPP-Zn-(S)-BINOL( Figure 3 B) SEM image;

[0024] Figure 4 Comparison of ECL performance of different materials;

[0025] Figure 5ECL comparison chart of TCPP-Zn-(S)-BINOL assembly in HEPES solution containing tyrosine enantiomers in Example 1;

[0026] Figure 6 The ECL diagram of tryptophan, phenylalanine, arginine, proline, histidine and tyrosine enantiomers of TCPP-Zn-(S)-BINOL assembly. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0028] Example 1

[0029] 144.2 mg of sodium dodecyl sulfate (SDS, molecular weight 288.38) was weighed and dissolved in 10 mL of ultrapure water to prepare a 0.05 M sodium dodecyl sulfate solution. 7.9 mg of tetrakis(4-carboxyphenyl)porphyrin (TCPP, molecular weight 790.77) was dissolved in 4 mL of the prepared sodium dodecyl sulfate solution. 5.73 mg of S-binaphthol (S-BINOL, molecular weight 286.32) was dissolved in 5 mL of the prepared sodium dodecyl sulfate solution. 6.6 mg of zinc acetate (Zn(OA)2, molecular weight 219.51) was dissolved in 1 mL of the prepared sodium dodecyl sulfate solution and stirred until completely dissolved. The S-binaphthol solution and the zinc acetate solution were added dropwise to the porphyrin solution, stirred at room temperature overnight, centrifuged, and dried for 6 h to obtain a tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly (TCPP-Zn-(S)-BINOL assembly).

[0030] 1 mg of TCPP-Zn-(S)-BINOL assembly was dispersed in 1 mL of ultrapure water to obtain a dispersion. 10 μL of the dispersion was pipetted with a pipette and applied to the surface of a glassy carbon electrode (GCE) and dried at room temperature. Then 10 μL of 10 mM TOAB ethanol solution was applied to the electrode surface and dried to obtain a glassy carbon electrode modified with tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly (TCPP-Zn-(S)-BINOL). TCPP-Zn-(S)-BINOL / GCE was used as the working electrode, a saturated calomel electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, HEPES with a pH of 8 was used as the electrolyte, and 15 mM hydrogen peroxide was used as the co-reactant. The electrochemiluminescence (ECL) intensity of the TCPP-Zn-(S)-BINOL assembly was tested by an electrochemiluminescence instrument.

[0031] Comparative Example 1

[0032] No zinc acetate solution is added: 144.2 mg of sodium dodecyl sulfate (SDS, molecular weight 288.38) is weighed and dissolved in 10 mL of ultrapure water to prepare a 0.05 M sodium dodecyl sulfate solution, 7.9 mg of tetrakis(4-carboxyphenyl)porphyrin (TCPP, molecular weight 790.77) is dissolved in 4 mL of the prepared sodium dodecyl sulfate solution, 5.73 mg of S-binaphthol ((S)-BINOL, molecular weight 286.32) is dissolved in 5 mL of the prepared sodium dodecyl sulfate solution, and stirred until completely dissolved, the S-binaphthol solution is added dropwise to the porphyrin solution, and 1 mL of the prepared sodium dodecyl sulfate solution is added, stirred at room temperature overnight, centrifuged, and dried for 6 hours to obtain tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol assembly (TCPP-(S)-BINOL assembly).

[0033] 1 mg of TCPP-(S)-BINOL assembly was dispersed in 1 mL of ultrapure water to obtain a dispersion. 10 μL of the dispersion was pipetted with a pipette and applied to the surface of a glassy carbon electrode (GCE) and dried at room temperature. Then 10 μL of 10 mM TOAB ethanol solution was applied to the electrode surface and dried to obtain a glassy carbon electrode (TCPP-(S)-BINOL) modified with tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly. TCPP-(S)-BINOL / GCE was used as the working electrode, a saturated calomel electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, HEPES with a pH of 8 was used as the electrolyte, and 15 mM hydrogen peroxide was used as the co-reactant. The electrochemiluminescence (ECL) intensity of the TCPP-(S)-BINOL assembly was tested by an electrochemiluminescence instrument.

[0034] like Figure 1 In Example 1, the cyclic voltammograms of TCPP, (S)-BINOL, TCPP-(S)-BINOL, and TCPP-Zn-(S)-BINOL with or without hydrogen peroxide are shown. As shown in Figures A, B, and C, when hydrogen peroxide is added, the cathode peak current increases slightly, indicating that TCPP, (S)-BINOL, and TCPP-(S)-BINOL have certain catalytic properties for hydrogen peroxide. Figure D is the cyclic voltammogram of TCPP-Zn-(S)-BINOL with or without hydrogen peroxide. When hydrogen peroxide is added, the cathode peak current value increases significantly. It can be seen that the TCPP-Zn-(S)-BINOL assembly has better catalytic properties for hydrogen peroxide and can produce a large amount of ·OH.

[0035] like Figure 2 From the infrared spectrum of TCPP in Example 1, it can be seen that 1686cm -1 The stretching vibration peak of the carbonyl group in the carboxyl group is at 3510 cm-1 and 3434cm -1 The peaks at (S)-BINOL are the stretching vibration peaks of the two phenolic hydroxyl groups in (S)-BINOL. From the comparison of the infrared spectra of TCPP-(S)-BINOL and TCPP, it can be seen that the carbonyl peak is blue-shifted to 1689 cm -1 , indicating that (S)-BINOL was successfully introduced. Comparison of the infrared spectra of TCPP-Zn-(S)-BINOL assembly with TCPP shows that the carbonyl peak blue-shifted to 1701 cm -1， This indicates that S-binaphthol was successfully introduced, and the intensity of the carbonyl peak was enhanced compared with the infrared spectrum of TCPP-(S)-BINOL, indicating the successful introduction of zinc ions.

[0036] like Figure 3 In Example A, the TCPP monomer presents an irregular large block structure; Figure 3 In Example 1, the TCPP-Zn-(S)-BINOL assembly utilizes the micelles formed by the surfactant SDS to induce the hydrophobic assembly unit to enter the interior of the micelle, and further assembles through weak interactions between the assembly unit molecules to present a smaller spherical structure, thereby achieving controllability of the size and shape of the self-assembled synthetic material.

[0037] like Figure 4 , which is a comparison chart of the ECL performance of TCPP, TCPP-(S)-BINOL, and TCPP-Zn-(S)-BINOL. The ECL intensity of TCPP is 31 a.u., and the ECL intensity of TCPP-(S)-BINOL is 41 a.u. Compared with TCPP, the ECL performance has no obvious change. When Zn is added, the ECL intensity of the TCPP-Zn-(S)-BINOL assembly is 1932 a.u., and the ECL performance is significantly enhanced. Compared with TCPP and TCPP-(S)-BINOL, TCPP-Zn-(S)-BINOL has a greater luminescence intensity and better luminescence performance.

[0038] like Figure 5 , is the ECL comparison diagram of the TCPP-Zn-(S)-BINOL assembly in Example 1 in a HEPES solution containing tyrosine enantiomers. It can be seen that when D-Tyr is added to the solution, the ECL intensity is 1966 a.u., which hardly causes changes in the ECL performance. However, when L-Tyr is added, the ECL intensity is significantly enhanced. The ECL intensity reaches 4056 a.u., and the recognition effect reaches 2.06:1. It can be seen that the TCPP-Zn-(S)-BINOL assembly has a better recognition effect on L-Tyr.

[0039] like Figure 6As shown, it can be seen that the TCPP-Zn-(S)-BINOL assembly has no obvious recognition effect on the five amino acids of tryptophan, phenylalanine, arginine, proline, and histidine, and only has a good recognition effect on the tyrosine enantiomer. When L-tyrosine is present, the ECL intensity increases significantly, and it can be seen that the TCPP-Zn-(S)-BINOL assembly has a good specific recognition effect on L-tyrosine.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect, characterized in that: Preparation method of the porphyrin MOF material: (1) dissolving tetrakis(4-carboxyphenyl)porphyrin, S-binaphthol and zinc acetate in an aqueous solution containing sodium dodecyl sulfate respectively; (2) mixing the S-binaphthol solution, the zinc acetate solution and the tetrakis(4-carboxyphenyl)porphyrin solution and stirring to react; (3) After the reaction, the solid is centrifuged, washed and dried to obtain a chiral recognition material tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly, which is a porphyrin MOF material; Application of porphyrin-based MOF materials for tyrosine enantiomer recognition: A glassy carbon electrode modified with tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly was used as the working electrode, a saturated calomel electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid was used as the electrolyte, and hydrogen peroxide was used as the co-reactant. The electrochemiluminescence intensity of the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly in an electrolyte containing L / D-tyrosine was measured by an electrochemiluminescence instrument for identification.

2. The method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect according to claim 1, characterized in that: The molar ratio of tetrakis(4-carboxyphenyl)porphyrin to S-binaphthol and zinc acetate is 1:(1-3):(1-4).

3. The method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect according to claim 1, characterized in that: The specific conditions of step (2) are to add the zinc acetate solution and the S-binaphthol solution dropwise into the tetrakis(4-carboxyphenyl)porphyrin solution, and stir the reaction at 20-50° C. for 6-15 hours.

4. The method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect according to claim 1, characterized in that: The tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly is dispersed in deionized water, and a drop of the dispersion is applied to the surface of a glassy carbon electrode and dried at room temperature to obtain a glassy carbon electrode modified with the tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly; the concentration of the dispersion is 1-5 mg / mL.

5. The method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect according to claim 4, characterized in that: A 10 mM ethanol solution of tetraoctylammonium bromide was prepared and drop-coated on the surface of the glassy carbon electrode modified with tetrakis(4-carboxyphenyl)porphyrin-S-binaphthol-zinc assembly to enhance the electrode stability.

6. The method for identifying tyrosine enantiomers based on porphyrin MOF material enhanced electrochemiluminescence effect according to claim 1, characterized in that: The pH of the N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid electrolyte is 4-9, and the amount of the coreaction reagent hydrogen peroxide is 1-25 mM.

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