CN111610172B - A dual-response optical probe rhodamine B derivative for the detection of hydrazine and cyanide in water samples - Google Patents

Abstract

The invention relates to a dual-response optical probe for detecting hydrazine and cyanide in a water sample. The optical probe takes dicyano as an identification group, and is designed and synthesized into hydrazine (N) ₂ H ₄ ) And Cyanide (CN) ^‑ ) 2- (4- (2, 2-dicyano) -6- (diethylamino) -2, 3-dihydro-1H-xanthene) benzoic acid. When N is present in the sample ₂ H ₄ When N ₂ H ₄ The reaction with dicyano can generate corresponding hydrazone structure, so that fluorescence excitation and emission generate blue shift, and hydrazine is detected by utilizing the change of the fluorescence signal, wherein the linear range is 0-10 mu M, and the detection limit is 80nM. Furthermore, when CN is present in the sample ^‑ When CN ^‑ Can generate nucleophilic addition reaction with dicyano to obviously enhance the fluorescence emission of the probe at 470nm, and the change of the fluorescence signal is utilized to carry out CN ^‑ The linear range was 0-30. Mu.M, and the detection limit was 0.33. Mu.M. Thus, the change in the different fluorescent signals can be used for N ₂ H ₄ And CN ^‑ Respectively measuring, overcoming the need of designing and synthesizing two different fluorescent probes to respectively detect N ₂ H ₄ And CN ^‑ Is not enough.

Description

A dual-response optical probe rhodamine B derivative for detecting hydrazine and cyanide in water samples Detection

Technical field

The invention relates to a dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid on water samples Detection of hydrazine and cyanide.

Background technique

As two important players in industrial production, hydrazine and cyanide have been widely used in chemical industry and agriculture such as pesticides, synthetic fibers, herbicides, plastic manufacturing, and resin industries. In sharp contrast to their uses, both hydrazine and cyanide can exhibit harmful effects on the body and are easily absorbed into the body through oral and skin absorption, causing damage to the central nervous system, heart, endocrine and metabolic systems. At the same time, due to its good water solubility, social and environmental safety are also facing threats and challenges. In order to prevent hydrazine and cyanide from causing harm to people's health and the surrounding ecological environment, countries around the world have strict regulations on the limit values of hydrazine and cyanide in the environment. Therefore, it is of great significance to establish efficient, highly sensitive, and highly selective methods for detecting hydrazine and cyanide.

The currently reported detection methods for hydrazine and cyanide mainly include: chromatography, titration, electrochemical analysis and other methods. These methods solve the detection problems of hydrazine and cyanide to varying degrees, but they also have problems with detection sensitivity and operating conditions. There are different drawbacks in terms of complexity or expensive instruments. Compared with the above methods, fluorescent probes have received widespread attention due to their high selectivity, high sensitivity, easy operation, non-damage, and applicability to biological environments. However, if we design and synthesize fluorescent probes for hydrazine or cyanide respectively, it will undoubtedly consume more financial and material resources, and it will also be unfriendly to the environment. Based on this, the present invention has established an efficient, selective and sensitive fluorescence analysis method to monitor hydrazine and cyanide in environmental water samples. It can not only improve detection efficiency and reduce probe synthesis costs, but also achieve control environmental pollution purposes.

Existing fluorescent probe technology detects N ₂ H ₄ and CN ^- , which requires the design and synthesis of two different fluorescent probes respectively, which not only consumes more time and cost, but also causes pollution to the environment. The invention overcomes the shortcomings of the prior art. The dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid was synthesized using a simple reaction. The probe can react with N ₂ H ₄ and CN ^- respectively based on different reaction mechanisms and solvent ratios to achieve detection under different fluorescence signals. The probe reacts with N ₂ H ₄ to generate (Z)-2-(6-(diethylamino)-4-(hydrazidinomethyl)-2,3-dihydro-1H-xanthene)benzoic acid , its maximum UV absorption wavelength is significantly reduced at 623nm and slightly enhanced at 420nm. The fluorescence emission ratio I ₅₆₅ / I ₆₄₅ increases with the increase in N ₂ H ₄ concentration. The emission fluorescence of the product after the addition reaction of the probe and CN ^- is significantly enhanced at 470 nm, and the fluorescence emission value increases with the increase of CN ^- concentration. The invention is used to separately measure the N ₂ H ₄ and CN ^- contents in wastewater samples. Based on the linear relationship between the fluorescence emission intensity ratio I ₅₆₅ / I ₆₄₅ and the N ₂ H ₄ concentration and the fluorescence enhancement at 470 nm and the CN ^- concentration, the calculations are respectively The lowest detection limits were found to be 80nM and 0.33μM, which enables a reasonable evaluation of the safety of the detected environment.

The dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid synthesized by the invention has stable optical properties , has good selectivity and high sensitivity, and is a quick and simple method for detecting traps and cyanogens.

Contents of the invention

The object of the invention is: a dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzene Detection of N ₂ H ₄ and CN ^- in water samples by formic acid.

The object of the present invention is achieved through the following technical solutions:

Synthesis of optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid:

Dissolve 0.403g 2-(6-(diethylamino)-4-formyl-2,3-dihydro-1H-xanthene)benzoic acid and 0.08g malononitrile in 10mL acetonitrile, then add 5 drops -7 drops of piperidine, reflux under nitrogen protection for 6 hours. After the reaction is completed, the mixture is spun dry, and the solid obtained is dissolved in methylene chloride. Then wash with water three times, then dry with anhydrous sodium sulfate, and finally use column chromatography for separation and purification. The eluent ratio is methylene chloride/methanol = 50:1 to obtain 0.288g of blue-violet solid, with a yield of 64%. .

The synthetic structural formula of the optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid is shown in Figure 1.

Advantages and beneficial effects of the present invention:

If existing fluorescent probe technology is used to detect N ₂ H ₄ and CN ^- , two different fluorescent probes need to be designed and synthesized respectively, which will not only pollute the environment, but also consume more time and cost. . The invention overcomes the shortcomings of the prior art. A dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid was synthesized using a simple organic reaction. The probe can react with N ₂ H ₄ and CN ^- respectively based on different reaction mechanisms and solvent ratios, Figure 2, to achieve detection under different fluorescence signals. The probe reacts with N ₂ H ₄ to generate (Z)-2-(6-(diethylamino)-4-(hydrazidinomethyl)-2,3-dihydro-1H-xanthene)benzoic acid , its maximum UV absorption wavelength is significantly reduced at 623nm and slightly enhanced at 420nm. The fluorescence emission ratio I ₅₆₅ / I ₆₄₅ increases with the increase in N ₂ H ₄ concentration. The emission fluorescence of the product after the addition reaction of the probe and CN ^- is significantly enhanced at 470 nm, and the fluorescence emission value increases with the increase of CN ^- concentration. The invention is used to separately measure the N ₂ H ₄ and CN ^- contents in wastewater samples. Based on the linear relationship between the fluorescence emission intensity ratio I ₅₆₅ / I ₆₄₅ and the N ₂ H ₄ concentration and the fluorescence enhancement at 470 nm and the CN ^- concentration, the calculations are respectively The lowest detection limits were found to be 80nM and 0.33μM, which enables a reasonable evaluation of the safety of the detected environment. The dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid synthesized by the invention has stable optical properties , has good selectivity and high sensitivity, and is a quick and simple method for detecting traps and cyanogens.

Description of drawings

Figure 1 is a synthesis diagram of 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid.

Figure 2 shows the synthesis of 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with N ₂ H ₄ and Reaction mechanism diagram of ^CN- .

Figure 3 shows the results of the synthesized 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid in deuterated chloroform. ^1H NMR spectrum.

Figure 4 shows the synthesized 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid in deuterated dimethyl ¹³ C NMR spectrum in sulfoxide.

Figure 5 shows the high-resolution mass spectrum of the synthesized probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid Figure, 452.1968[M+H ⁺ ] in the spectrum is the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene )Molecular ion peak of benzoic acid.

Figure 6 shows the synthesized probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and N ₂ respectively High-resolution mass spectrum of the product after the reaction of H ₄ and CN ^- .

Figure 7 shows the reaction between 20 μM probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and 40 μM N ₂ H ₄ UV absorption spectrum (A) and fluorescence emission spectrum (B) before (dashed line) and after (solid line) reaction.

Figure 8 shows the reaction of 20 μM probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with 100 μM CN ^- (dashed line) and post (solid line) UV absorption spectrum (A) and fluorescence emission spectrum (B).

Figure 9 shows 20μM probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid in the presence of other interfering substances Detect the fluorescence spectrum histograms of N ₂ H ₄ (A) and CN ^- (B) respectively.

Figure 10 shows the reaction of 20 μM probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with different concentrations of N ₂ H Fluorescence spectrum change after the action of ₄ (A) and the linear relationship between fluorescence intensity I ₅₆₅ /I ₆₄₅ and N ₂ H ₄ concentration.

Figure 11 shows 20 μM probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and different concentrations of CN ^- Fluorescence spectrum change after action (A) and linear relationship between fluorescence intensity λ _em =470nm and CN ^- concentration.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and examples:

Example 1

Dissolve 0.403g 2-(6-(diethylamino)-4-formyl-2,3-dihydro-1H-xanthene)benzoic acid and 0.08g malononitrile in 10mL acetonitrile, then add 5 drops -7 drops of piperidine, reflux under nitrogen protection for 6 hours. After the reaction is completed, the mixture is spun dry, and the solid obtained is dissolved in methylene chloride. Then wash with water three times, then dry with anhydrous sodium sulfate, and finally use column chromatography for separation and purification. The eluent ratio is methylene chloride/methanol = 50:1 to obtain 0.288g of blue-violet solid, with a yield of 64%. , the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid was obtained.

Prepare 9 probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid solutions in parallel with a concentration of 20 μM. Add N ₂ H ₄ standard solutions containing different concentrations to them. After 35 minutes, measure the fluorescence spectra of the above solutions and record the fluorescence emission intensity. According to the relationship between the fluorescence intensity value I ₅₆₅ / I ₆₄₅ and the N ₂ H ₄ concentration Draw a standard curve.

Prepare a solution of probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with a concentration of 20 μM, and add it to After 35 minutes of sample solution, measure its fluorescence spectrum, record the change in fluorescence emission intensity, and calculate the concentration of N ₂ H ₄ in the sample based on the above standard curve.

Prepare 9 probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid solutions in parallel with a concentration of 20 μM. Add CN ^- standard solutions containing different concentrations to them. After 30 minutes, measure the fluorescence spectra of the above solutions, record the fluorescence emission intensity, and draw a standard curve based on the relationship between the fluorescence intensity value at 470 nm and the CN ^- concentration.

Prepare a solution of probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with a concentration of 20 μM, and add it to Sample solution, after 30 minutes, measure its fluorescence spectrum, record the change in fluorescence emission intensity, and calculate the concentration of CN ^- in the sample according to the above standard curve.

After the probe was synthesized, the product was tested with a nuclear magnetic resonance spectrometer, and its hydrogen spectrum 3 was obtained. Its chemical shift data is: ¹ H NMR (400MHz, Chloroform-d) δ = 8.21 (d, J = 7.8Hz, 1H) ,8.09(s,1H),7.69(t,J＝7.6Hz,1H),7.57(t,J＝7.6Hz,1H),7.15(d,J＝7.5Hz,1H),6.53(d,J＝ 2.5Hz,1H),6.47(d,J＝9.0Hz,1H),6.37(dd,J＝9.0,2.5Hz,1H),3.42(d,J＝7.4Hz,4H),2.83(t,J＝ 6.2Hz, 2H), 2.19–2.09 (m, 2H), 1.67 (p, J = 6.3Hz, 2H), 1.22 (t, J = 7.0Hz, 6H) to obtain its carbon spectrum 4, and its chemical shift data is : ¹³ C NMR (101MHz, DMSO-d ₆ ) δ = 167.37, 160.66, 154.88, 150.93, 148.28, 147.96, 135.97, 133.20, 131.10, 131.06, 130.14, 129.56, 127.48, 119.62, 1 18.90,118.08,111.85,110.74, 108.82,

97.07, 62.21, 44.58, 26.54, 25.85, 24.79, 20.63, 19.09, 12.99. High-resolution mass spectrum Figure 5 shows that its molecular weight is ESI-MS m/z[M+H ⁺ ]=452.1968.

The above characterization proved that the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid was successfully synthesized.

High-resolution mass spectrometry Figure 6 verifies that the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and N Mechanism _{of 2H4} and CN ^- reaction.

Example 2

1. Spectral experiment

First, the UV-visible absorption spectrum and Fluorescence emission spectrum. As shown in Figure 7, 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid itself shows at 623 nm Strong absorption band. After reacting with N ₂ H ₄ for 35 minutes, the absorption band at 623 nm weakened significantly, while the absorption peak at 420 nm slightly enhanced. At the same time, the color of the solution changed from blue-violet to yellow, indicating that N ₂ H ₄ The new substance generated by the reaction with 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid has different properties from the probe. Spectral properties. In addition, the fluorescence spectrum of the probe solution was measured. Figure 7-B shows that when excited at 515nm, obvious fluorescence enhancement and weakening signals can be observed at 565nm and 645nm respectively. The changes in fluorescence spectral properties before and after the reaction of the above probe with N ₂ H ₄ can be used to detect the content of N ₂ H ₄ in the sample. In addition, after the probe reacted with ^CN- for 30 minutes, an obvious enhanced fluorescence signal could be observed at 470nm. Under fluorescent lamp irradiation, it was found that the red fluorescence of the original probe had been converted to blue at this time, so the probe and ^CN- The changes in fluorescence spectral properties before and after the reaction can also be used to detect the CN ^- content in the sample (Figure 8).

In order to verify the response of probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid to N ₂ H ₄ and CN respectively ^-Selectivity of detection, the present invention combines 20 μM 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with other Possible interfering components (500μM, NH ₄ ⁺ ,Ca ²⁺ ,Mg ²⁺ ,Zn ²⁺ ,Fe ³⁺ ,Ac ^- ,Br ^- ,Cl ^- ,ClO ₄ ^- ,F ^- ,I ^- ,NO ₂ ^- , HSO ₃ ^- ,NO ₃ ^- ,CO ₃ ^2- ,S ^2- ,SO ₃ ^2- ,SO ₄ ^2- ,PO ₄ ^3- ,H ₂ O ₂ ) were incubated for 35 minutes respectively. After the incubation was completed, use fluorescence spectrophotometry The meter records the excitation wavelength of probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid at 515nm and 375nm respectively. Fluorescence emission spectrum at wavelength. As shown in Figure 9, when the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid was mixed with N After the interaction between ₂ H ₄ and CN ^- , its fluorescence emission ratio I ₅₆₅ / I ₆₄₅ and the emission at 470 nm were significantly enhanced, while after the interaction with other analytes, its fluorescence did not change significantly. At the same time, in the presence of N ₂ H ₄ or CN ^- and other interfering substances, 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H- Xanthene)benzoic acid still has a good recognition effect on N ₂ H ₄ or CN ^- , as shown in Figure 9. This result proves that 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid can react with N ₂ H ₄ and CN ^- achieves specific recognition.

2. The concentration titration experiment is based on the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid which can react with N ₂ H ₄ or CN ^- has the characteristics of specific recognition. The present invention studied the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H- Quantitative detection capability of xanthene)benzoic acid for N ₂ H ₄ or CN ^- . The present invention uses fluorescence emission spectrum to examine its quantitative performance. 20μL 1mmol/L probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and 480μL dimethylsulfide Mix the sulfone and add different volumes of 1mM N ₂ H ₄ solution. Adjust the volume to 1mL with 12mM phosphate buffered saline solution. After incubation for 35 minutes, use a fluorescence spectrophotometer to record the probe 2-(4-(2,2 -Fluorescence emission spectrum of biscyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and its reaction product with N ₂ H ₄ . As can be seen from Figure 9-A, its fluorescence emission spectrum increases with the increase of N ₂ H ₄ concentration, 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3- The fluorescence emission of dihydro-1H-xanthene)benzoic acid molecule at 565nm gradually increases, accompanied by the weakening of the fluorescence emission at 645nm, and its emission intensity has a good linear relationship with the concentration of 0-10μMN ₂ H _4. The detection The out-of-limit LOD can reach 80nM, Figure 9-B. It shows that the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid can be used to detect N ₂ H ₄ using a fluorescence spectrometer Perform quantitative analysis.

Mix 20 μL of 1 mmol/L probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid with 880 μL DMSO. And add different volumes of 1mM undimethylhydrazine solution, adjust the volume to 1mL with 12mM phosphate buffer saline solution, incubate for 30 minutes, use a fluorescence spectrophotometer to record the probe 2-(4-(2,2-dicyanide) Fluorescence emission spectrum of 6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and its reaction product with cyanide. It can be seen from Figure 11-A that the fluorescence emission spectrum increases with the increase of CN ^- concentration, 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydrogen The fluorescence emission of -1H-xanthene)benzoic acid molecule at 470 nm gradually increases, and its emission intensity shows a good linear relationship with the 0–30 μM CN ^- concentration. The detection limit LOD can reach 0.22 μM, as shown in Figure 11-B The probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid can be used for quantitative analysis of CN ^- using a fluorescence spectrometer. .

3. Determination of hydrazine and cyanide content in water samples

In order to verify the applicability of the probe for the detection of N ₂ H ₄ and CN ^- in actual samples, the present invention measured the contents of N ₂ H ₄ and CN ^- in the water sample of Yuxiu Lake of Lanzhou University and performed a standard addition recovery experiment. The experimentally measured recovery rate of N ₂ H ₄ in the Yuxiu Lake water sample is shown in Table 1. The data in the table illustrates that the probe 2-(4-(2,2-dicyano)-6-(diethylamino) )-2,3-Dihydro-1H-xanthene)benzoic acid can be applied to the detection of N ₂ H ₄ and CN ^- in actual water samples.

The specific methods are:

a.Sample processing

The water sample of Yuxiu Lake was taken from Yuxiu Lake of Lanzhou University, and the obtained water sample was filtered with a 0.22 μm microporous filter membrane.

b. Fluorescence spectrometry to determine the content of hydrazine and cyanide in actual samples

Take 500 μL of the actual sample processed above and add 20 μL of 1mmol/L probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-oxygen Mix anthracene) benzoic acid solution and 480 μL dimethyl sulfoxide, shake well, and incubate at room temperature for 35 minutes. Use a fluorescence spectrophotometer to record the fluorescence emission spectrum at an excitation wavelength of 515 nm. In addition, a certain amount of N ₂ H ₄ standard solution is added to the actual sample, and after the volume is adjusted, the test is performed according to the above operation, and the corresponding standard recovery rate is calculated. Table 1 shows the experimental data of N ₂ H ₄ spike recovery rate in Yuxiu Lake water samples.

Table 1 Determination of N ₂ H ₄ in actual samples by 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and spike recovery rate.

Take 100 μL of the actual sample processed above, and add 20 μL of 1mmol/L probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-oxygen respectively. Mix anthracene) benzoic acid solution and 880 μL dimethyl sulfoxide, shake well, and incubate at room temperature for 30 minutes. Use a fluorescence spectrophotometer to record the fluorescence emission spectrum at an excitation wavelength of 375 nm. In addition, a certain amount of CN ^- standard solution is added to the actual sample, and after the volume is adjusted, the test is performed according to the above operation, and the corresponding standard recovery rate is calculated. Table 2 shows the experimental data of CN ^- spiked recovery rate in Yuxiu Lake water samples.

Table 2 Determination and spiking of 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid on actual sample CN ^- Recovery rate

By pairing the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid and its combination with N ₂ H ₄ or CN ^- Study on the optical properties before and after the reaction proves that the molecular probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-oxygen synthesized by the present invention Heteroanthracene) benzoic acid can realize the determination of N ₂ H ₄ or CN ^- through fluorescence emission spectrum. Compared with traditional detection methods, the present invention has stable optical properties, good specificity, high sensitivity and high detection efficiency, and is a fast and efficient method. _A simple and easy way to detect _N2H4 or ^CN- .

Claims (1)

1. A dual-response optical probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid is used for detection To determine the content of hydrazine and cyanide in water samples, the steps are: a. Exploring the spectral properties of the probe: Accurately weigh 2.25 mg of the probe, dissolve it in dimethyl sulfoxide, and adjust the volume to 5.0 mL to obtain a 1 mmol/L probe stock solution. Take 20 μL of the 1 mmol/L probe stock solution. , add 480 μL dimethyl sulfoxide, and dilute to 1.0 mL with 12 mM phosphate buffer solution to obtain 20 μM probe solution A; measure the probe 2-(4-(2,2- The UV absorption and fluorescence emission spectra of dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid have a maximum UV absorption wavelength of 623nm and a strong peak at 645nm. fluorescence emission; b. Probe response to N ₂ H ₄ : Add 40 μL of 1 mmol/L N ₂ H ₄ aqueous solution to probe solution A. After 35 minutes, (Z)-2-(6-(diethylamino)- 4-(Ahydrinomethyl)-2,3-dihydro-1H-xanthene)benzoic acid, its UV absorption maximum wavelength is significantly reduced at 623nm, slightly enhanced at 420nm, and the original probe is at 645nm. The fluorescence emission decreased significantly, and at the same time, a new fluorescence emission appeared at 565nm, which was also accompanied by a change in the color of the solution from dark blue to light yellow. The probe 2-(4-(2,2-dicyano)-6-(di Ethylamino)-2,3-dihydro-1H-xanthene) benzoic acid can perform ratiometric qualitative detection and analysis of N ₂ H ₄ in fluorescence emission mode; another probe solution A is added with a concentration of 0-40 μM. N ₂ H ₄ aqueous solution, after 35 minutes, observe its color change, detect the fluorescence emission spectrum, record its fluorescence emission intensity at 565nm and 645nm, according to the ratio of the concentration of 0-10μMN ₂ H ₄ and the fluorescence emission spectrum intensity I ₅₆₅ /I ₆₄₅ establishes a standard linear equation: y=0.154+0.738[N ₂ H ₄ ], the detection limit LOD can reach 80nM; take another probe solution A and add the wastewater sample containing N ₂ H ₄ , and observe it after 35 minutes. Color change, while using fluorescence emission spectrum to detect water samples containing N ₂ H ₄ , and calculate the N ₂ H ₄ content in the sample according to the standard curve equation; c. Probe response to CN ^- : Take another 20 μL of 1 mmol/L probe stock solution, add 880 μL of dimethyl sulfoxide, and dilute to 1.0 mL with 12 mM phosphate buffer solution to obtain 20 μM probe solution B; Add 100 μM CN ^- aqueous solution to it. After 30 minutes, the maximum UV absorption wavelength is reduced at 623nm, and the emission fluorescence of the generated product at 470nm is significantly enhanced. The color of the solution changes from dark blue to light blue, and the fluorescence color changes from red to blue. , the probe 2-(4-(2,2-dicyano)-6-(diethylamino)-2,3-dihydro-1H-xanthene)benzoic acid can also detect CN in fluorescence emission mode ^- Carry out quantitative detection analysis; take another probe solution B and add a CN ^- aqueous solution with a concentration of 0-100 μM. After 30 minutes, use fluorescence emission spectrum detection to record its fluorescence emission intensity at 470 nm. According to the value of 0-30 μM CN ^- Concentration and fluorescence emission spectrum intensity establish a standard linear equation: y=85.85+4.353[CN ^- ], the detection limit LOD can reach 0.22μM; add another probe solution B to the wastewater sample containing CN ^- , and after 30 minutes, use fluorescence The emission spectrum detects water samples containing ^CN- , and the CN ^- content in the sample is calculated according to the standard curve equation.