CN109596593B

CN109596593B - Method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water

Info

Publication number: CN109596593B
Application number: CN201910107634.XA
Authority: CN
Inventors: 李玉鑫; 于明珂; 李光明; 赵丽娜
Original assignee: Heilongjiang University
Current assignee: Heilongjiang University
Priority date: 2019-02-02
Filing date: 2019-02-02
Publication date: 2021-03-09
Anticipated expiration: 2039-02-02
Also published as: CN109596593A

Abstract

A method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water relates to a method for detecting antibiotics in drinking water. In the present invention, the existing lanthanide metal-organic framework is unstable in dependence on excitation wavelength, and the existing method for determining antibiotics has the problems that professional instruments are required, the pretreatment is cumbersome, and the operation cost is high. Detection methods: 1. Preparation of Tb-dcpcpt crystal; 2. Preparation of RhB@Tb-dcpcpt composite material; 3. Preparation of RhB@Tb-dcpcpt dispersion; 4. Fluorescence detection. The invention is used for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water.

Description

Method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water

Technical Field

The invention relates to a method for detecting antibiotics in drinking water.

Background

Lanthanide metal-organic frameworks (Ln-MOFs) are crystalline organic/inorganic hybrid materials with characteristic luminescence properties, which are self-assembled by multidentate bonds and inorganic nodes of rare earth ions through coordination bonds. In Ln-MOFs, multiple emission characteristics can be easily obtained by adjusting the energy transfer (antenna effect) of the ligand to lanthanide ions, thereby providing a sensitive platform for the color and intensity of the luminescence of Ln-MOFs. On the other hand, the sensitivity of coordination environment leads to the instability of the Ln-MOFs luminescence. Utilizing its instability, Ln-MOFs can be used as sensors for environmental factors such as temperature, pH, solvent effect, etc., which have been widely reported and used as sensitive thermometers, pH indicators and solvent probes. However, instability in excitation wavelength dependence is rarely addressed and exploited.

Porosity is a crucial feature of Ln-MOFs, contributing to the encapsulation of good fluorophores, especially fluorescent dye molecules with excitation wavelength independent properties, to build ground state atoms by ion exchange processes and/or space-limiting effects. By introducing the fluorescent dye into the porous Ln-MOFs, the bi-uniform multi-emission dye @ Ln-MOF composite material not only provides a new way for designing luminescent materials irrelevant to the excitation wavelength, but also provides an opportunity for obtaining durable and sensitive sensors through photon-induced electron transfer and fluorescence resonance energy transfer. Perturbation of different analytes in the various components of a multi-emission sensor may alter the luminescent color and emission intensity ratio of the elements, thereby providing an effective platform for easy and convenient discrimination of the components in a sequence combination. By simultaneously considering the glow-discoloration and on/off processes, multi-selective glow sensing can be easily achieved. But Ln-MOFs based multi-selective materials or composites that are not affected by the excitation wavelength are rarely reported, while systematic analysis of the sensing mechanism remains a major challenge to the development of this type of sensor.

In addition, antibiotics are important drugs for the prevention and treatment of certain diseases, especially resistance to bacterial infections in aqueous environments. However, due to the wide use of antibiotics, more antibiotic residues occur in food, animal and even drinking water. Prolonged intake of these contaminated foods can lead to serious diseases such as immune decline, allergic reactions, hereditary genetic defects, and various types of cancers. Currently, various expensive and complicated methods have been developed for the determination of antibiotics, such as chromatographic techniques, optical sensors, electrochemical sensors and biosensors. Although these techniques have great advantages in terms of sensitivity and selectivity, they necessarily require specialized instruments, require cumbersome pre-processing, and are costly to operate. Therefore, as a luminescence sensor, the dye @ Ln-MOF can provide a simple and convenient antibiotic detection method with high sensitivity. In addition, in the real world, mixtures of antibiotics are often present. Thus, multi-selective luminescence sensing of antibiotics in aqueous solution is of great significance and challenge.

Disclosure of Invention

The invention provides a method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water, aiming at solving the problems that the existing lanthanide metal-organic framework is unstable in dependence on excitation wavelength, and the existing method for determining antibiotics needs professional instruments, is complex in pretreatment and high in operation cost.

A method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water is carried out according to the following steps:

firstly, preparing Tb-dcpcpt crystals:

(I) reacting Tb (NO)₃)₃·6H₂O, 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydro-1, 2,4-triazole, N' -dimethylformamide and H₂Mixing O to obtain a mixture, placing the mixture in a high-temperature reaction kettle, and sealing for 24-72 hours at the temperature of 150-200 ℃ to perform solvothermal reaction to obtain a crystal sample;

the 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydrogen-1, 2,4-triazole and Tb (NO)₃)₃·6H₂The molar ratio of O is 1 (0.5-2); the volume ratio of the mol of the 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydrogen-1, 2,4-triazole to the N, N' -dimethylformamide is 0.1mmol (5-10) mL; the N, N' -dimethylformamide and H₂The volume ratio of O is 1 (0.1-2);

secondly, washing the crystal sample with N, N' -dimethylformamide and ethanol for 3 to 5 times respectively to obtain Tb-dcpcpt crystals;

secondly, preparing a RhB @ Tb-dcpcpt composite material:

immersing Tb-dcpcpt crystal in 10 concentration^-4mol/L～10^-5Keeping the solution in mol/L rhodamine B water solution for 12-48 h to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain a RhB @ Tb-dcpcpt composite material;

thirdly, preparing a RhB @ Tb-dcpcpt dispersion liquid:

under the condition of stirring, dispersing the RhB @ Tb-dcpcpt composite material into water to obtain a RhB @ Tb-dcpcpt dispersion liquid;

the concentration of the RhB @ Tb-dcpcpt dispersion liquid is 0.1 g/L-10 g/L;

fourthly, fluorescence detection:

mixing drinking water with the RhB @ Tb-dcpcpt dispersion liquid to obtain drinking water to be detected, irradiating the drinking water to be detected by adopting ultraviolet light with the wavelength of 300-390 nm, and observing the color of the solution;

the volume ratio of the drinking water to the RhB @ Tb-dcpcpt dispersion liquid is 1 (0.5-2);

the drinking water contains nitrofuran antibiotics or quinolone antibiotics;

when the drinking water contains the nitrofuran antibiotics and the concentration of the nitrofuran antibiotics in the drinking water is higher than 0.502 mu mol/L, the color of the solution is subjected to fluorescence quenching by yellow light;

when the drinking water contains the quinolone antibiotics and the concentration of the quinolone antibiotics in the drinking water is higher than 0.448 mu mol/L, the color of the solution is changed from yellow to white firstly and then to blue.

In the first step of the invention, the 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydro-1, 2,4-triazole, namely 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1H-1,2,4-triazole in English, is abbreviated as H in the invention₃dcpcpt。

The molecular formula of the Tb-dcpcpt crystal prepared in the first step of the invention is [ (CH)₃)₂NH₂][Tb₃(dcpcpt)₃(HCOO)]·DMF·15H₂O, abbreviated Tb-dcpcpt.

The invention has the beneficial effects that:

selection of [ (CH)₃)₂NH₂][Tb₃(dcpcpt)₃(HCOO)]·DMF·15H₂O (Tb-dcpcpt) and rhodamine B cationic dye (RhB) RhB @ Tb-dcpcpt composite materials were prepared. The composite material has the common luminescence of Tb-dcpcpt and RhB, and generates durable yellow light emission under the excitation of 300-390 nm. The 14 antibiotics are detected by luminescence, and the good identification capability is shown no matter on the luminescence intensity of the nitrofuran antibiotics or the luminescence color of the quinolone antibiotics. The sensing behavior has good sensitivity, selectivity and recoverability, which is little affected by the excitation wavelength.

The cation RhB is fixed in an anion Ln-MOF channel through ion exchange, and a yellow luminescent composite material irrelevant to the excitation wavelength is successfully synthesized. The composite material has higher sensitivity and selective detection capability on nitrofuran antibiotics (NZF and NFT). Furthermore, for the quinolone antibiotics (CPFX and NFX), RhB @ Tb-dcpcpt also showed a clear luminescence-color change from yellow to white to blue. The excitation wavelength has little effect on the sensing behavior. The composite material has low detection limit (the detection limit for NZF and NFT is respectively 0.502 mu mol/L and 0.448 mu mol/L, and the detection limit for CPFX and NFX is respectively 2.16 mu mol/L and 0.63 mu mol/L), good stability and selectivity, can be recycled, is a promising furan and quinolone antibiotic sensor, and has potential practical value in the aspect of water quality monitoring.

Drawings

FIG. 1 is an X-ray powder diffraction pattern, 1 is the measured X-ray powder diffraction curve of the RhB @ Tb-dcpcpt composite material prepared in the second step of the example, 2 is the measured X-ray powder diffraction curve of the Tb-dcpcpt crystal prepared in the first step of the example, and 3 is the fitted X-ray powder diffraction curve of the Tb-dcpcpt crystal;

FIG. 2 is a nitrogen adsorption desorption spectrum, 1 being Tb-dcpcpt crystals prepared in the first step of the example, and 2 being RhB @ Tb-dcpcpt composite material prepared in the second step of the example;

FIG. 3 is an ultraviolet-visible absorption spectrum, wherein 1 is Tb-dcpcpt crystals prepared in the first step of the example, 2 is rhodamine B, and 3 is RhB @ Tb-dcpcpt composite material obtained by filtering an aqueous solution;

FIG. 4 is a solid state three dimensional fluorescence spectrum of Tb-dcpcpt crystals prepared in one step one of the examples;

FIG. 5 is a solid state three dimensional fluorescence spectrum of a RhB @ Tb-dcpcpt composite prepared in step two of the example;

FIG. 6 is a measured X-ray powder diffraction pattern of the RhB @ Tb-dcpcpt composite prepared in the second example step and the RhB @ Tb-dcpcpt composite after filtration of the aqueous solution, 1 is the RhB @ Tb-dcpcpt composite prepared in the second example step and 2 is the RhB @ Tb-dcpcpt composite after filtration of the aqueous solution;

FIG. 7 shows the fluorescence spectra of RhB @ Tb-dcpcpt dispersions prepared in the third step of the example at different excitation wavelengths;

FIG. 8 shows the fluorescence spectra of an NZF-containing aqueous solution added to a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE MODEL III, 1 is a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE MODEL III, and 2 is an NZF-containing aqueous solution added to a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE MODEL III;

FIG. 9 shows the fluorescence spectra of an aqueous NFT-containing solution added to a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE STEP three, 1 is a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE STEP three, and 2 is an aqueous NFT-containing solution added to a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE STEP three;

FIG. 10 shows the fluorescence spectra of a dispersion of RhB @ Tb-dcpcpt prepared in EXAMPLE MODEL III after addition of an aqueous solution containing CPFX, 1 shows a dispersion of RhB @ Tb-dcpcpt prepared in EXAMPLE MODEL III, and 2 shows a dispersion of RhB @ Tb-dcpcpt prepared in EXAMPLE MODEL III after addition of an aqueous solution containing CPFX;

FIG. 11 is a plot of the fluorescence spectrum of a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE MODEL III after addition of an aqueous solution containing NFX, 1 being a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE MODEL III, 2 being a plot of a RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE MODEL III after addition of an aqueous solution containing NFX;

FIG. 12 is a plot of the fluorescence spectra of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to aqueous solutions of varying concentrations containing NZF;

FIG. 13 is a graph comparing the relative fluorescence intensity at 544nm for different concentrations of NZF-containing aqueous solutions;

FIG. 14 is a plot of the fluorescence spectra of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to different concentrations of NFT-containing aqueous solutions;

FIG. 15 is a graph comparing the relative fluorescence intensity at 544nm for different concentrations of NFT-containing aqueous solutions;

FIG. 16 is a bar graph of the intensity of the fluorescence peak at 544nm of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example, in the presence of other antibiotics, after addition of different concentrations of NZF containing aqueous solutions;

FIG. 17 is a bar graph of the intensity of the fluorescence peak at 544nm after addition of different concentrations of NFT-containing aqueous solutions in the presence of other antibiotics for the RhB @ Tb-dcpcpt dispersion prepared in step three of the example;

FIG. 18 is a plot of the cyclicity of addition of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example to an aqueous solution containing NZF, 1 for the RhB @ Tb-dcpcpt dispersion, 2 for the RhB @ Tb-dcpcpt dispersion to an aqueous solution containing NZF;

FIG. 19 is a graph of the cyclicity of addition of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example to an aqueous solution containing NFT, 1 for the RhB @ Tb-dcpcpt dispersion, and 2 for the RhB @ Tb-dcpcpt dispersion to an aqueous solution containing NFT;

FIG. 20 is a graph of the X-ray powder diffraction pattern of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after filtration added to an aqueous solution containing various antibiotics, 1 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NFX, 2 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing CPFX, 3 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NFT, 4 the RhB Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NZF, and 5 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of a dispersion containing NZF;

FIG. 21 is a CIE diagram of the fluorescence of the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step after addition of an aqueous solution containing CPFX or NFX in the presence of ACL, 1 is a mixture of the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step with ACL, 2 is the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step after addition of an aqueous solution containing CPFX in the presence of ACL, 3 is the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step after addition of an aqueous solution containing NFT in the presence of ACL;

FIG. 22 is a plot of the fluorescence of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of various concentrations of aqueous solutions containing CPFX;

FIG. 23 is a CIE diagram of fluorescence of RhB @ Tb-dcpcpt dispersions prepared in the third example step after addition of aqueous solutions containing CPFX at different concentrations, 1 is a 0mmol/L aqueous solution of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 2 is a 1mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 3 is a 2mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 4 is a 3mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 5 is a 4mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 6 is a 5mmol/L aqueous solution containing CPTb-dcpcL of dispersions prepared in the third example step, 7 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution containing CPFX at a concentration of 6mmol/L, 8 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution containing CPFX at a concentration of 7mmol/L, and 9 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution containing CPFX at a concentration of 8 mmol/L;

FIG. 24 is a graph of the change in fluorescence color of RhB @ Tb-dcpcpt dispersions prepared in EXAMPLE MODEL III after addition of varying concentrations of aqueous solutions containing CPFX or NFX, a for RhB @ Tb-dcpcpt dispersions prepared in EXAMPLE MODEL III after addition of varying concentrations of aqueous solutions containing CPFX, b for RhB @ Tb-dcpcpt dispersions prepared in EXAMPLE MODEL III after addition of varying concentrations of aqueous solutions containing NFX;

FIG. 25 is a plot of the fluorescence spectra of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of various concentrations of NFX-containing aqueous solutions;

FIG. 26 is a CIE diagram of fluorescence of the RhB @ Tb-dcpcpt dispersion prepared in the third example step after addition to various concentrations of NFX-containing aqueous solutions, 1 is a 0mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 2 is a 1mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 3 is a 2mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 4 is a 3mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 5 is a 4mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 6 is a NFX mmol/L NFX-Tb-dcpcpt aqueous solution of the RhB @ 853 mmol/L dispersion prepared in the third example step, 7 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution having a concentration of NFX was added at 6mmol/L, 8 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution having a concentration of NFX was added at 7mmol/L, and 9 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution having a concentration of NFX was added at 8 mmol/L;

FIG. 27 is a plot of the fluorescence peak of a RhB @ Tb-dcpcpt dispersion prepared according to step three of the example;

FIG. 28 shows the fluorescence peak of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to an aqueous solution containing CPFX;

FIG. 29 shows the fluorescence peak of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to an aqueous solution containing NFX;

FIG. 30 is a fluorescence plot of Tb-dcpcpt crystals, CPFX solid and NFX solid prepared in example step one, 1 Tb-dcpcpt crystals, 2 NFX solid and 3 CPFX solid prepared in example step one.

Detailed Description

The technical solution of the present invention is not limited to the following specific embodiments, but includes any combination of the specific embodiments.

The first embodiment is as follows: the method for detecting the nitrofuran antibiotics or the quinolone antibiotics in the drinking water is carried out according to the following steps:

firstly, preparing Tb-dcpcpt crystals:

secondly, washing the crystal sample with N, N' -dimethylformamide and ethanol for 3 to 5 times respectively to obtain Tb-dcpcpt crystals; secondly, preparing a RhB @ Tb-dcpcpt composite material:

tb-dcpcpcppt crystals were impregnated at a concentration of 10^-4mol/L～10^-5Keeping the solution in mol/L rhodamine B water solution for 12-48 h to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain a RhB @ Tb-dcpcpt composite material;

thirdly, preparing a RhB @ Tb-dcpcpt dispersion liquid:

the concentration of the RhB @ Tb-dcpcpt dispersion liquid is 0.1 g/L-10 g/L;

fourthly, fluorescence detection:

the drinking water contains nitrofuran antibiotics or quinolone antibiotics;

In the embodiment, the nitrofuran antibiotics and the quinolone antibiotics do not exist simultaneously in the drinking water.

The beneficial effects of the embodiment are as follows:

selection of [ (CH)₃)₂NH₂][Tb₃(dcpcpt)₃(HCOO)]·DMF·15H₂O (Tb-dcpcpt) and rhodamine B cationic dye (RhB) RhB @ Tb-dcpcpt composite materials were prepared. The composite material has the common luminescence of Tb-dcpcpt and RhB, and generates durable yellow light emission under the excitation of 300-390 nm. The 14 antibiotics are subjected to luminescenceThe detection shows that the fluorescent powder shows good identification capability no matter the luminous intensity of the nitrofuran antibiotics or the luminous color of the quinolone antibiotics. The sensing behavior has good sensitivity, selectivity and recoverability, which is little affected by the excitation wavelength.

The second embodiment is as follows: the first difference between the present embodiment and the specific embodiment is: the 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydrogen-1, 2,4-triazole and Tb (NO) in the first step₃)₃·6H₂The molar ratio of O is 1 (0.5-1). The rest is the same as the first embodiment.

The third concrete implementation mode: this embodiment is different from the first or second embodiment in that: the volume ratio of the mol of the 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydrogen-1, 2,4-triazole to the N, N' -dimethylformamide in the first step is 0.1mmol (8-10) mL. The other is the same as in one or both of the first and second embodiments.

The fourth concrete implementation mode: the difference between this embodiment mode and one of the first to third embodiment modes is: the N, N' -dimethylformamide and H in the first step₂The volume ratio of O is 1 (0.25-2). The others are the same as in one of the first to third embodiments.

The fifth concrete implementation mode: this embodimentThe difference between the formula and one of the first to fourth embodiments is: in the second step, Tb-dcpcpt crystal is immersed in 10 concentration^-5And (3) keeping the solution in mol/L rhodamine B water solution for 24-48 h to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain the RhB @ Tb-dcpcpt composite material. The other is the same as one of the first to fourth embodiments.

The sixth specific implementation mode: the difference between this embodiment and one of the first to fifth embodiments is: in the second step, Tb-dcpcpt crystal is immersed in 10 concentration^-5And (3) keeping the solution in mol/L rhodamine B water solution for 12-24 h to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain the RhB @ Tb-dcpcpt composite material. The other is the same as one of the first to fifth embodiments.

The seventh embodiment: the difference between this embodiment and one of the first to sixth embodiments is: the concentration of the RhB @ Tb-dcpcpt dispersion liquid in the third step is 1 g/L-10 g/L. The other is the same as one of the first to sixth embodiments.

The specific implementation mode is eight: the present embodiment differs from one of the first to seventh embodiments in that: the concentration of the RhB @ Tb-dcpcpt dispersion liquid in the third step is 0.1 g/L-1 g/L. The other is the same as one of the first to seventh embodiments.

The specific implementation method nine: the present embodiment differs from the first to eighth embodiments in that: the volume ratio of the drinking water to the RhB @ Tb-dcpcpt dispersion liquid in the fourth step is 1 (1-2). The rest is the same as the first to eighth embodiments.

The detailed implementation mode is ten: the present embodiment differs from one of the first to ninth embodiments in that: the volume ratio of the drinking water to the RhB @ Tb-dcpcpt dispersion liquid in the fourth step is 1 (0.5-1). The other is the same as one of the first to ninth embodiments.

The following experiments are adopted to verify the effect of the invention:

the first embodiment is as follows:

firstly, preparing Tb-dcpcpt crystals:

(ii) 0.1mmol of Tb (NO)₃)₃·6H₂O, 0.1mmol of 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydro-1, 2,4-triazole, 8mL of N, N' -dimethylformamide and 2mL of H₂Mixing O to obtain a mixture, placing the mixture in a high-temperature reaction kettle, and sealing for 72 hours at the temperature of 160 ℃ to perform solvothermal reaction to obtain a crystal sample;

secondly, washing the crystal sample with N, N' -dimethylformamide and ethanol for 3 times respectively to obtain Tb-dcpcpt crystals;

secondly, preparing a RhB @ Tb-dcpcpt composite material:

1.6mg of Tb-dcpcpt crystals were immersed in 8mL of 10 concentration solution^-5Keeping the solution in mol/L rhodamine B water solution for 24 hours to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain a RhB @ Tb-dcpcpt composite material;

thirdly, preparing a RhB @ Tb-dcpcpt dispersion liquid:

the concentration of the RhB @ Tb-dcpcpt dispersion liquid is 1 g/L;

fourthly, fluorescence detection:

the volume ratio of the drinking water to the RhB @ Tb-dcpcpt dispersion liquid is 1: 1;

the drinking water contains nitrofuran antibiotics or quinolone antibiotics;

Materials and instruments of this example: the procedure in the first embodiment3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydro-1, 2,4-triazole is produced by Jinan Chemicals, Ltd, and has the product number of 130811AS, the name of English is 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1H-1,2,4-triazole, and in the embodiment, the 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydro-1, 2,4-triazole is abbreviated AS H₃dcpcpt。

Tb₂O₃Reacting with nitric acid to obtain Tb (NO)₃)₃·6H₂And O. Other chemicals were purchased from commercial companies and used without purification. All antibiotic manufacturers are robust technology limited.

Ultraviolet (UV) spectra were collected on a Perkin-Elmer Lambda 35 spectrometer. C, H, O and N were subjected to elemental analysis on a Perkin-Elmer 2400 analyzer. Photoluminescence (PL) spectra were measured using an edinburgh FLS920 spectrofluorometer and the corrected spectra were obtained from the calibration curve provided by the instrument.

The crystalline yield of Tb-dcpcpt prepared in step one of this example: 1.6mg (2.02 wt%).

Theoretical calculation of carbon (C) in Compound C₅₇H₆₇N₁₁O₃₆Tb₃The mass ratio of the components is 34.94%; hydrogen (H) in compounds C₅₇H₆₇N₁₁O₃₆Tb₃In the compound C, oxygen (O) accounts for 3.45% by mass₅₇H₆₇N₁₁O₃₆Tb₃Wherein the mass ratio of nitrogen (N) in the compound C is 29.40%₅₇H₆₇N₁₁O₃₆Tb₃The mass ratio of the component (A) to the component (B) is 7.86%.

Via actual elemental analysis testing: carbon (C) in Tb-dcpcpt crystals accounted for 34.68%; hydrogen (H) accounted for 3.48% in Tb-dcpcpt crystals, oxygen (O) accounted for 29.44% in Tb-dcpcpt crystals, and nitrogen (N) accounted for 8.03% in Tb-dcpcpt crystals.

FIG. 1 is an X-ray powder diffraction pattern, 1 is a measured X-ray powder diffraction curve of a RhB @ Tb-dcpcpt composite material prepared in the second step of the example, 2 is a measured X-ray powder diffraction curve of Tb-dcpcpt crystals prepared in the first step of the example, and 3 is a fitting X-ray powder diffraction curve of the Tb-dcpcpt crystalsDiffraction profile. This example synthesizes Tb-dcpcpt crystals, which are composed of a rigid ligand H, according to previous literature reports₃dcpcpt and Tb (NO)₃)₃·6H₂O is generated under solvothermal conditions. The resulting Tb-dcpcpt crystals had a PXRD spectrum consistent with the previously reported single crystal structure, confirming the successful synthesis of Tb-dcpcpt (FIG. 1). Notably, Tb-dcpcpt crystals not only have permanent porosity (specific surface area 801 m)²(ii)/g; one-dimensional channel dimension of

Porosity 49.8%) and has an anionic structure, and therefore, it is utilized as a carrier for encapsulating cationic dyes.

Rhodamine b (rhb) is an excellent fluorescent carrier for chemical/biological sensing. However, quenching induced by polymerization limits the wide application of RhB. In this example, one encapsulation strategy is achieved by trapping and inhibiting RhB molecules into the porous backbone. The Tb-dcpcpt crystal is soaked in a RhB aqueous solution, and the dye is introduced into a Tb-dcpcpt channel to obtain the RhB @ TB-dcpcpt composite material. After packaging, the crystal color under sunlight changes from transparent to pink, and the luminescent color under ultraviolet light changes from green to yellow. PXRD patterns before and after introduction of RhB showed the same framework structure (fig. 1).

FIG. 2 is a nitrogen adsorption desorption spectrum, 1 being Tb-dcpcpt crystals prepared in the first step of the example, and 2 being RhB @ Tb-dcpcpt composite material prepared in the second step of the example; n is a radical of₂Adsorption isotherms and uv-vis absorption further confirmed successful loading of RhB (fig. 2 and 5).

Several factors drive the implementation of encapsulation: in one aspect, the kinetic size of RhB

Comparable to the window size of Tb-dcpcpt

Thereby providing the possibility of trapping RhB in the pores. After packaging of RhB, multiple framesThe pore channels are almost sealed (fig. 2). On the other hand, the anionic Tb-dcpcpt framework is able to attract RhB cations, resulting in an ion exchange process. Rapid encapsulation of soak solutions (1 day) and lower RhB concentrations (10)^-5mol/L) further confirmed that RhB easily entered Tb-dcpcpt channels.

Photoluminescence of Tb-dcpcpt crystals and RhB @ Tb-dcpcpt composite:

the luminescence spectra of Tb-dcpcpt crystals, RhB and RhB @ Tb-dcpcpt composites were studied in the solid state. FIG. 4 is a solid state three dimensional fluorescence spectrum of Tb-dcpcpt crystals prepared in one step one of the examples; as shown in FIG. 4, Tb-dcpcpt crystals showed Tb at 489nm, 544nm, 581nm and 619nm, respectively³⁺Sharp characteristic peaks corresponding to 5D4 → 7FJ (J ═ 6, 5, 4, and 3) transitions.

FIG. 5 is a solid state three dimensional fluorescence spectrum of a RhB @ Tb-dcpcpt composite prepared in step two of the example; RhB can represent a significant red emission ranging from 600nm to 670nm, so RhB @ Tb-dcpcpt composite shows Tb³⁺And RhB (FIG. 5), the strong emission at 489nm and 544nm being attributed to the skeletal emission, the other strong emission near 635nm being attributed to the emission of RhB.

As the synthesized RhB @ Tb-dcpcpt composite material can detect antibiotics in an aqueous solution, the stability and the luminescence property of the RhB @ Tb-dcpcpt composite material in an aqueous medium are detected. Suspending the RhB @ Tb-dcpcpt composite material into water by stirring to obtain a RhB @ Tb-dcpcpt dispersion liquid, and then filtering the RhB @ Tb-dcpcpt composite material in the RhB @ Tb-dcpcpt dispersion liquid to obtain a RhB @ Tb-dcpcpt composite material after filtering an aqueous solution;

in the RhB @ Tb-dcpcpt composite, the transfer of fluorescence resonance energy from the backbone to RhB may contribute to co-luminescence of the backbone and the dye. FIG. 3 is an ultraviolet-visible absorption spectrum, wherein 1 is Tb-dcpcpt crystals prepared in the first step of the example, 2 is rhodamine B, and 3 is RhB @ Tb-dcpcpt composite material obtained by filtering an aqueous solution. As shown in FIG. 3 and FIG. 4, the UV-Vis absorption spectrum of RhB is mainly around 544nm, almost completely overlapping with the transition band 5D4 → 7F2 of Tb-dcpcpt. After coating, the luminescence intensity of Tb-dcpcpt at 544nm was significantly reduced, confirming the existence of efficient fluorescence resonance energy transfer.

FIG. 6 is a measured X-ray powder diffraction pattern of the RhB @ Tb-dcpcpt composite prepared in the second example step and the RhB @ Tb-dcpcpt composite after filtration of the aqueous solution, 1 is the RhB @ Tb-dcpcpt composite prepared in the second example step and 2 is the RhB @ Tb-dcpcpt composite after filtration of the aqueous solution; the PXRD pattern of RhB @ Tb-dcpcpt filtered from the suspension had little change, indicating that the framework was still intact after being suspended in water (fig. 6).

Small amounts of RhB were detected by uv-vis spectroscopy, indicating that RhB was located in the channels of the scaffold (fig. 3).

The results show that the composite material has good stability, and simultaneously show that the nano-pore channel has a certain limiting effect on the aggregation and the dissociation of the RhB, so that the stability of the composite material is greatly improved. The experimental result also proves the application of RhB @ Tb-dcpcpt in aqueous solution chemical/biological sensing.

FIG. 7 shows the fluorescence spectra of RhB @ Tb-dcpcpt dispersions prepared in the third step of the example at different excitation wavelengths; the luminescent color of the RhB @ Tb-dcpcpt composite material keeps stable yellow light emission in the whole range of the excitation wavelength of 300nm to 390 nm. This contribution solves the problem of instability of lanthanide sensors with respect to excitation wavelength in terms of luminescence intensity and color. Although the RhB @ Tb-dcpcpt composite has persistent yellow emission in aqueous solution (fig. 7), the luminescence of the encapsulated RhB changes from 635nm in fig. 5 to 590nm in fig. 7 due to the concentration effect of the dye molecules. Importantly, these results demonstrate the absence of aggregation-induced quenching of RhB molecules by using a porous network to encapsulate RhB dyes.

Detection of nitrofuran antibiotics:

to the RhB @ Tb-dcpcpt dispersion prepared in step three of the example, an antibiotic-containing aqueous solution was added at a concentration of 0.01mol/L and irradiated with ultraviolet light having a wavelength of 320nm to investigate the ability of RhB @ Tb-dcpcpt to detect trace amounts of antibiotic, the volume ratio of the antibiotic-containing aqueous solution to the RhB @ Tb-dcpcpt dispersion being 1: 1. The antibiotic in the water solution containing the antibiotic is one of the following 6 types of common antibiotics 14, such as beta-lactam antibiotics (penicillin PCL, amoxicillin ACL, cefixime CFX, cefradine CFD), aminoglycoside antibiotics (gentamycin GTM, kanamycin KNM), macrolide antibiotics (roxithromycin ROX, azithromycin AZM), quinolone antibiotics (ciprofloxacin CPFX, norfloxacin NFX), nitrofuran antibiotics (furazolidone NZF, nitrofurantoin NFT) and other antibiotics (vancomycin VCC, lincomycin LCC).

FIG. 8 is a plot of the fluorescence spectrum of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NZF; 1 is the RhB @ Tb-dcpcpt dispersion prepared in example step three, 2 is the RhB @ Tb-dcpcpt dispersion prepared in example step three with the addition of an aqueous solution containing NZF; FIG. 9 shows the fluorescence spectra of a dispersion of RhB @ Tb-dcpcpt prepared in step three of the example after addition of an aqueous NFT-containing solution; 1 is the RhB @ Tb-dcpcpt dispersion prepared in example step three, 2 is the RhB @ Tb-dcpcpt dispersion prepared in example step three with the addition of an NFT-containing aqueous solution; FIG. 10 is a fluorescence spectrum of a dispersion of RhB @ Tb-dcpcpt prepared in step three of the example after addition of an aqueous solution containing CPFX; 1 is the RhB @ Tb-dcpcpt dispersion prepared in example step three, 2 is the RhB @ Tb-dcpcpt dispersion prepared in example step three with the addition of an aqueous solution containing CPFX; FIG. 11 is a plot of the fluorescence spectrum of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NFX; 1 is the RhB @ Tb-dcpcpt dispersion prepared in example step three, 2 is the RhB @ Tb-dcpcpt dispersion prepared in example step three with the addition of an aqueous solution containing NFX; from FIGS. 8-11, RhB @ Tb-dcpcpt exhibited high luminescence quenching upon addition of nitrofuran antibiotics (e.g., NZF and NFT).

FIG. 20 is a graph of the X-ray powder diffraction pattern of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after filtration added to an aqueous solution containing various antibiotics, 1 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NFX, 2 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing CPFX, 3 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NFT, 4 the RhB Tb-dcpcpt dispersion prepared in step three of the example after addition of an aqueous solution containing NZF, and 5 the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of a dispersion containing NZF; PXRD confirms that the structure of RhB @ Tb-dcpcpt is intact after the sensing experiment on NZF and NFT (FIG. 20).

An aqueous solution containing a nitrofuran antibiotic was added to the RhB @ Tb-dcpcpt dispersion prepared in step three of the example, and irradiated with ultraviolet light having a wavelength of 320nm to investigate the detection limit of the RhB @ Tb-dcpcpt for the nitrofuran antibiotic, the volume ratio of the aqueous solution containing the nitrofuran antibiotic to the RhB @ Tb-dcpcpt dispersion being 1: 1. Using the Stern-Volmer (SV) equation: i is₀/I＝1+K_SV×[C]In which K is_SVIs a quenching constant (mol/L)^-1The concentration of the nitrofuran antibiotic in the aqueous solution containing the nitrofuran antibiotic is set to [ C ]]，[C]Has the unit of mol/L, I₀And I is the luminescence intensity in the absence and presence, respectively, of a nitrofuran antibiotic, either furazolidone NZF or nitrofurantoin NFT.

FIG. 12 is a plot of the fluorescence spectra of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to aqueous solutions of varying concentrations containing NZF; calculating and plotting the fluorescence intensity of different curves in FIG. 12 by using a Stern-Volmer (SV) equation to obtain a graph 13, wherein the graph 13 is a comparison graph of the relation between the relative fluorescence intensity and the 544nm of the aqueous solution containing NZF at different concentrations, the graph 14 is a fluorescence spectrum of the aqueous solution containing NFT at different concentrations in the RhB @ Tb-dcpcpt dispersion prepared in the third step of the example, and the graph 15 is a comparison graph of the relation between the relative fluorescence intensity and the 544nm of the aqueous solution containing NFT at different concentrations by using a Stern-Volmer (SV) equation to calculate and plot the fluorescence intensity of different curves in FIG. 14; the SV curves for NZF and NFT are in good linear relationship, RhB @ TB-dcppt vs. K for NZF and NFT_SVThe values are respectively 5.98X 10⁴(mol/L)^-1And 6.69X 10⁴(mol/L)^-1(FIGS. 13 and 15). K of fluorescence measurement based on triplicate blank solutions_SVThe values and standard deviations (σ ═ 0.010) determine the detection limits (LOD ═ 3 σ/K) for RhB @ Tb-dcpcpt for NZF and NFT_SV) Calculated values were 0.502. mu. mol/L (99.47ppb) and 0.448. mu. mol/L (106.7ppb), respectively. The method of the embodiment has far superior sensitivityMost of the reported NZF and NFT fluorescent probes meet the standards of the United states environmental protection agency and the world health organization for the highest allowable content of antibiotics in drinking water.

The excellent sensitivity to NZF and NFT indicates that RhB @ Tb-dcpcpt has high quenching efficiency to nitrofuran antibiotics, but is not sensitive to other antibiotics. On this basis, the present example further examined the selectivity of detection of nitrofuran antibiotics in the presence of other antibiotics. In a control experiment, an aqueous solution containing an antibiotic (PCL, ACL, CFX, CFD, GTM, KNM, ROX, AZM, CPFX, NFX, VCC or LCC) at a concentration of 1mmol/L was added to the RhB @ Tb-dcpcpt dispersion prepared in the third example step, and then aqueous solutions containing NZF or NFT at different concentrations were added and irradiated with ultraviolet light having a wavelength of 320nm, the volume ratio of the aqueous solution containing the antibiotic to the RhB @ Tb-dcpcpt dispersion prepared in the third example step was 1:1, and the volume ratio of the aqueous solution containing NZF or NFT at different concentrations to the RhB @ Tb-dcpcpt dispersion prepared in the third example step was 1: 1.

FIG. 16 is a bar graph of the intensity of the fluorescence peak at 544nm of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example, in the presence of other antibiotics, after addition of different concentrations of NZF containing aqueous solutions; FIG. 17 is a bar graph of the intensity of the fluorescence peak at 544nm after addition of different concentrations of NFT-containing aqueous solutions in the presence of other antibiotics for the RhB @ Tb-dcpcpt dispersion prepared in step three of the example; in the case of excess of other antibiotics (FIGS. 16 and 17), there was a slight change in luminescence intensity for RhB @ Tb-dcpcpt. After the nitrofuran antibiotics are introduced into a mixture of RhB @ Tb-dcpcpt and other antibiotics, luminescence is obviously quenched, which shows that RhB @ TB-dcpcpt has higher quenching selectivity on nitrofuran.

In addition, the cyclicity of detection of nitrofuran antibiotics by RhB @ Tb-dcpcpt was investigated by repeating the cycle of adding a 1mmol/L NZF-or NFT-containing aqueous solution to the RhB @ Tb-dcpcpt dispersion prepared in one step three of the example at a volume ratio of 1:1, irradiating with ultraviolet light having a wavelength of 320nm, centrifuging and washing several times with water after use, filtering to obtain RhB @ Tb-dcpcpt again, then dispersing the RhB @ Tb-dcpcpt again in water to obtain a 1g/L RhB @ Tb-dcpcpt dispersion, adding a 1mmol/L NZF-or NFT-containing aqueous solution to the 1g/L RhB Tb-dcpcpt dispersion at a volume ratio of 1:1, irradiating with ultraviolet light having a wavelength of 320 nm. FIG. 18 is a plot of the cyclicity of addition of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example to an aqueous solution containing NZF, 1 for the RhB @ Tb-dcpcpt dispersion, 2 for the RhB @ Tb-dcpcpt dispersion to an aqueous solution containing NZF; FIG. 19 is a graph of the cyclicity of addition of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example to an aqueous solution containing NFT, 1 for the RhB @ Tb-dcpcpt dispersion, and 2 for the RhB @ Tb-dcpcpt dispersion to an aqueous solution containing NFT; the fluorescent detection is proved to have good recoverability of the nitrofuran antibiotics, regeneration and large-scale recycling (FIGS. 18 and 19).

Mechanism of action of RhB @ TB-dcpcpt on NZF and NFT: first, PXRD confirmed that the RhB @ Tb-dcpcpt structure was intact after the sensing experiments for NZF and NFT (fig. 20). Secondly, according to the common general knowledge of the people in the field, the antibiotic has strong absorption in the ultraviolet-visible spectrum, NZF and NFT, at 300 nm-400 nm, and the luminescence of RhB @ Tb-dcpcpt is quenched due to competitive photon absorption. Third, the Lowest Unoccupied Molecular Orbital (LUMO) energies of NZF and NFT are lower than other antibiotics, suggesting that light-induced electron transfer is one mechanism of luminescence quenching observed in these systems. The result shows that the coexistence of electron transfer and competitive photon absorption enables the furan compound to show good luminescence quenching effect compared with other proved analysis substances.

Detection of quinolone antibiotics:

the luminescent discoloration process was tested by adding a 0.01mol/L aqueous solution containing a quinolone antibiotic in a volume ratio of 1:1 to the RhB @ Tb-dcpcpt dispersion prepared in example step three, and irradiating with ultraviolet light having a wavelength of 320 nm.

FIG. 27 is a plot of the fluorescence peak of a RhB @ Tb-dcpcpt dispersion prepared according to step three of the example; FIG. 28 shows the fluorescence peak of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to an aqueous solution containing CPFX; FIG. 29 shows the fluorescence peak of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition to an aqueous solution containing NFX; as CPFX and NFX increase, the ligand center emission produces a deep photochromic shift. This indicates that there is radiative capture from RhB @ Tb-dcpcpt to the quinolone molecule. Therefore, the central emission of the ligand plays a dominant role in the emission spectrum, and the color of the emitted light changes from yellow to white to blue.

To the RhB @ Tb-dcpcpt dispersion prepared in step three of the example, an aqueous solution containing a quinolone antibiotic was added and irradiated with ultraviolet light having a wavelength of 320nm, and the volume ratio of the aqueous solution containing a quinolone antibiotic to the RhB @ Tb-dcpcpt dispersion was 1: 1. FIG. 22 is a plot of the fluorescence of a RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of various concentrations of aqueous solutions containing CPFX; FIG. 23 is a CIE diagram of fluorescence of RhB @ Tb-dcpcpt dispersions prepared in the third example step after addition of aqueous solutions containing CPFX at different concentrations, 1 is a 0mmol/L aqueous solution of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 2 is a 1mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 3 is a 2mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 4 is a 3mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 5 is a 4mmol/L aqueous solution containing CPFX of RhB @ Tb-dcpcpt dispersions prepared in the third example step, 6 is a 5mmol/L aqueous solution containing CPTb-dcpcL of dispersions prepared in the third example step, 7 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution containing CPFX at a concentration of 6mmol/L, 8 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution containing CPFX at a concentration of 7mmol/L, and 9 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution containing CPFX at a concentration of 8 mmol/L; FIG. 24 shows the change in fluorescence color of the RhB @ Tb-dcpcpt dispersion prepared in the third example step after addition of aqueous solutions containing CPFX or NFX at different concentrations, a shows the RhB @ Tb-dcpcpt dispersion prepared in the third example step after addition of aqueous solutions containing CPFX at different concentrations, and b shows the RhB @ Tb-dcpcpt dispersion prepared in the third example step after addition of aqueous solutions containing CPFX at different concentrationsAdding prepared RhB @ Tb-dcpcpt dispersion liquid into NFX-containing aqueous solutions with different concentrations; FIG. 25 is a plot of the fluorescence spectra of the RhB @ Tb-dcpcpt dispersion prepared in step three of the example after addition of various concentrations of NFX-containing aqueous solutions; FIG. 26 is a CIE diagram of fluorescence of the RhB @ Tb-dcpcpt dispersion prepared in the third example step after addition to various concentrations of NFX-containing aqueous solutions, 1 is a 0mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 2 is a 1mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 3 is a 2mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 4 is a 3mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 5 is a 4mmol/L NFX-containing aqueous solution of the RhB @ Tb-dcpcpt dispersion prepared in the third example step, 6 is a NFX mmol/L NFX-Tb-dcpcpt aqueous solution of the RhB @ 853 mmol/L dispersion prepared in the third example step, 7 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution having a concentration of NFX was added at 6mmol/L, 8 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution having a concentration of NFX was added at 7mmol/L, and 9 for the RhB @ Tb-dcpcpt dispersion prepared in example step three, an aqueous solution having a concentration of NFX was added at 8 mmol/L; according to fig. 22 to 26, the luminescent color of the sample clearly changed from yellow to white and then to blue. Tb increased with increasing concentrations of CPFX and NFX³⁺And the RhB component decreased rapidly, but the NFX ligand component remained unchanged and the CPFX ligand component even increased (fig. 22 and 25). Thus, with the continued addition of CPFX and NFX, blue light emission gradually dominates, resulting in emission colors from yellow to white to blue. According to FIG. 24, the luminescence color of the sample turned white when the concentration of CPFX or NFX was 4mmol/L and blue when the concentration was 7mmol/L, which is a relatively low visual detection limit. The intensity of light was monitored at 544nm, with detection limits for CPFX and NFX of 2.16. mu. mol/L (716ppb) and 0.63. mu. mol/L (201ppb), respectively. The result shows that RhB @ Tb-dcpcpt has double and low visual detection limit and wide detection range.

The selectivity of detection of quinolone drugs in the presence of other antibiotics was subsequently investigated. Adding an aqueous solution containing antibiotics (PCL, ACL, CFX, CFD, GTM, KNM, ROX, AZM, VCC or LCC) with the concentration of 1mmol/L into the RhB @ Tb-dcpcpt dispersion prepared in the third step of the example, then adding an aqueous solution containing CPFX or NFX with the concentration of 0.01mol/L, and irradiating with ultraviolet light with the wavelength of 320nm, wherein the volume ratio of the aqueous solution containing the antibiotics to the RhB @ Tb-dcpcpt dispersion prepared in the third step of the example is 1:1, and the volume ratio of the aqueous solution containing the CPFX or NFX to the RhB @ Tb-dcpcpt dispersion prepared in the third step of the example is 1: 1. FIG. 21 is a CIE diagram of the fluorescence of the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step after addition of an aqueous solution containing CPFX or NFX in the presence of ACL, 1 is a mixture of the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step with ACL, 2 is the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step after addition of an aqueous solution containing CPFX in the presence of ACL, 3 is the RhB @ Tb-dcpcpt dispersion prepared in EXAMPLE one third step after addition of an aqueous solution containing NFT in the presence of ACL; the RhB @ Tb-dcpcpt composite material has a clear change process of the fluorescence color from yellow to blue after adding quinolone drugs such as CPFX and NFX (FIG. 21). After the quinolone drugs are introduced into the mixture of the RhB @ Tb-dcpcpt and other antibiotics, the luminescence color is obviously changed into blue, and the fact that the RhB @ Tb-dcpcpt has high selectivity on the quinolone compounds in the luminescence color is proved (figure 21).

Mechanism of luminescent discoloration process: first, the PXRD patterns of RhB @ Tb-dcpcpt before and after detection of quinolone antibiotics are basically consistent, which indicates that the fluorescence discoloration phenomenon is unrelated to structural change (FIG. 20). Next, a luminescence peak analysis was performed on RhB @ Tb-dcpcpt (FIGS. 27 to 29). As CPFX and NFX increase, the ligand center emission produces a deep photochromic shift. This indicates that there is radiative capture from RhB @ Tb-dcpcpt to the quinolone molecule. Therefore, the central emission of the ligand plays a dominant role in the emission spectrum, and the color of the emitted light changes from yellow to white to blue. Thirdly, the quinolone compound has weak luminescence at 400 nm-500 nm under the excitation of 320nm, and H₃The luminescence of dcpcpt is similar, another reason for the dominance of blue light (fig. 30), and fig. 30 shows Tb-dcpcpt crystals, CPFX solid and NFX prepared in one step of the exampleFluorescence of the solid, 1 is Tb-dcpcpt crystals prepared in one step one of the examples, 2 is NFX solid, and 3 is CPFX solid. Thus, the luminescent discoloration process of RhB @ Tb-dcpcpt to quinolone compounds is due to coexistence of luminescent emission of the analyte with energy transfer interference and perturbation of energy transfer of the ligand to the lanthanide ion.

Claims

1. A method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water is characterized in that the method for detecting the nitrofuran antibiotics or quinolone antibiotics in the drinking water is carried out according to the following steps:

firstly, preparing Tb-dcpcpt crystals:

the molecular formula of the Tb-dcpcpt crystal is [ (CH)₃)₂NH₂][Tb₃(dcpcpt)₃(HCOO)]·DMF·15H₂O；

Secondly, preparing a RhB @ Tb-dcpcpt composite material:

immersing Tb-dcpcpt crystal in 10 concentration^-4mol/L～10^-5Keeping the solution in mol/L rhodamine B water solution for 12 to 48 hours to obtain pink crystals, and washing the pink crystals with deionized waterWashing and drying in the air to obtain a RhB @ Tb-dcpcpt composite material;

thirdly, preparing a RhB @ Tb-dcpcpt dispersion liquid:

the concentration of the RhB @ Tb-dcpcpt dispersion liquid is 0.1 g/L-10 g/L;

fourthly, fluorescence detection:

the drinking water contains nitrofuran antibiotics or quinolone antibiotics; the nitrofuran antibiotics are furazolidone or nitrofurantoin; the quinolone antibiotic is ciprofloxacin or norfloxacin;

when the drinking water contains furazolidone and the concentration of the furazolidone in the drinking water is higher than 0.502 mu mol/L, the color of the solution is subjected to fluorescence quenching by yellow light;

when the drinking water contains nitrofurantion and the concentration of the nitrofurantion in the drinking water is higher than 0.448 mu mol/L, the color of the solution is quenched by yellow light;

when the drinking water contains ciprofloxacin, and the concentration of the ciprofloxacin in the drinking water is higher than 2.16 mu mol/L, the color of the solution is changed from yellow to white firstly and then to blue;

when norfloxacin is contained in the drinking water and the concentration of norfloxacin in the drinking water is higher than 0.63 mu mol/L, the color of the solution is changed from yellow to white firstly and then to blue.

2. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydro-1, 2,4-triazole and Tb (NO) in step one₃)₃·6H₂The molar ratio of O is 1 (0.5-1).

3. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein the volume ratio of the moles of 3- (3, 5-dicarboxyphenyl) -5- (4-carboxyphenyl) -1-hydrogen-1, 2,4-triazole to N, N' -dimethylformamide in step one is 0.1mmol (8-10) mL.

4. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein the N, N' -dimethylformamide and H in step one₂The volume ratio of O is 1 (0.25-2).

5. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water as claimed in claim 1, wherein Tb-dcpcpt crystal is immersed in 10 concentration solution^-5And (3) keeping the solution in mol/L rhodamine B water solution for 24-48 h to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain the RhB @ Tb-dcpcpt composite material.

6. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water as claimed in claim 1, wherein Tb-dcpcpt crystal is immersed in 10 concentration solution^-5And (3) keeping the solution in mol/L rhodamine B water solution for 12-24 h to obtain pink crystals, washing the pink crystals with deionized water, and drying the pink crystals in the air to obtain the RhB @ Tb-dcpcpt composite material.

7. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein the concentration of the RhB @ Tb-dcpcpt dispersion in step three is 1 g/L-10 g/L.

8. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein the concentration of the RhB @ Tb-dcpcpt dispersion in step three is 0.1g/L to 1 g/L.

9. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein the volume ratio of the drinking water to the RhB @ Tb-dcpcpt dispersion in the fourth step is 1 (1-2).

10. The method for detecting nitrofuran antibiotics or quinolone antibiotics in drinking water according to claim 1, wherein the volume ratio of the drinking water to the RhB @ Tb-dcpcpt dispersion in the fourth step is 1 (0.5-1).