CN116789660B - A 1,8-naphthalimide derivative and its preparation method and application as Hg2+ colorimetric probe and fluorescence switch - Google Patents

Abstract

The present invention discloses a 1,8-naphthalimide derivative and a preparation method thereof and an application thereof as a Hg ²⁺ colorimetric probe and a fluorescence switch. A BBN compound is reacted with 2-aminothiazole to obtain a 1,8-naphthalimide derivative. The present invention designs and synthesizes a novel 1,8-naphthalimide derivative (BBNS) having an aminothiazole structure at the 4-position. BBNS can identify Hg ²⁺ through multiple channels: it can detect Hg ²⁺ colorimetrically in a solution, can be made into a test paper-type portable sensor for naked eye identification of Hg ²⁺ , and can also be used as an ultrasensitive Hg ²⁺ fluorescence switch with a response range of picomolar level.

Description

1, 8-Naphthalimide derivative, preparation method thereof and application thereof as Hg 2+ colorimetric probe and fluorescent switch

Technical Field

The invention belongs to the new material technology, and particularly relates to a1, 8-naphthalimide Hg ²⁺ colorimetric probe, a fluorescent switch and a preparation method thereof.

Background

Hg ²⁺ is a toxic heavy metal ion of great concern, and sensitive and accurate detection of Hg ²⁺ is critical to the environment and human health. The fluorescent probe is widely applied to heavy metal ion detection due to good selectivity, high sensitivity, simple operation and in-situ real-time use. The 1, 8-naphthalimide derivative is an important heavy metal ion fluorescent probe, wherein the Hg ²⁺ fluorescent probe is very actively researched. The prior art reports a disulfide bond-linked 1, 8-naphthalimide dimer fluorescent probe with a detection range of 0-150 mu M and a detection limit of 0.38 mu M for Hg ²⁺, the prior art reports a 1, 8-naphthalimide fluorescent probe with a thiosemicarbazide group at the C-4 position of the naphthalene ring, the detection range of 18-40 mu M for Hg ²⁺ and a detection limit of 0.138 mu M, the prior art reports a photocrosslinked solid fluorescent sensing film containing 1, 8-naphthalimide for detection of Hg ²⁺ in aqueous solution, the detection range of 0-400 mu M for Hg ²⁺ and the detection limit of 2.5 mu M, the prior art reports a 1, 8-naphthalimide analog fluorescent probe with a detection range of 0-100 mu M for Hg ²⁺ in acetonitrile/water (1:1, v/v, pH=7.0, HEPES buffer solution), the prior art reports a detection range of 17.4-nM for Hg-24.62M for Hg-62, and the prior art reports a detection range of 24-62.16 mu M for Hg-62.

The existing 1, 8-naphthalimide Hg ²⁺ fluorescent probe is used for detecting Hg ²⁺ in a solution, few portable sensors can be manufactured, the response range of the existing probe to Hg ²⁺ is generally in a range from micromoles to nanomoles, and the fluorescent performance of the probe gradually changes along with the increase of the concentration of Hg ²⁺ in a wider range. In a very narrow Hg ²⁺ concentration range, the 1, 8-naphthalimide Hg ²⁺ fluorescent switch with the fluorescence performance suddenly changing along with the change of Hg ²⁺ concentration and the response concentration reaching picomolar level is not reported.

Disclosure of Invention

The invention synthesizes a novel multichannel Hg ²⁺ colorimetric and fluorescent probe through two-step reaction, and the probe can be used for colorimetric detection of Hg ²⁺ in a solution, can be prepared into a test paper type portable sensor for naked eye recognition of Hg ²⁺, and can also be used as a hypersensitive Hg ²⁺ fluorescent switch in a picomolar concentration response range.

The invention adopts the following technical scheme:

a1, 8-naphthalimide derivative has the chemical structural formula as follows:

The invention discloses a preparation method of the 1, 8-naphthalimide derivative, which comprises the step of reacting a BBN compound with 2-aminothiazole to obtain the 1, 8-naphthalimide derivative. Preferably, the reaction is carried out in the presence of a noble metal catalyst, an inorganic base, an organic ligand, and a solvent. Further preferred, the noble metal catalyst comprises a palladium catalyst, preferably an inorganic palladium catalyst, the inorganic base comprises cesium salts, potassium salts, sodium salts, etc., preferably carbonates, the organic ligand comprises phosphine ligands, preferably phenylphosphines, and the solvent is an organic solvent such as DMF.

In the invention, the reaction is carried out under an inert gas such as nitrogen, the reaction temperature is 100-150 ℃, preferably 110-130 ℃, and the reaction time is 1-5 hours, preferably 2-4 hours.

In the invention, the molar ratio of BBN compound, 2-aminothiazole, noble metal catalyst, inorganic base and organic ligand is 1:1-2:0.1-0.3:1-2:0.3-0.65.

The invention discloses application of the 1, 8-naphthalimide derivative as or in preparation of an Hg ²⁺ colorimetric probe, and preferably application of the 1, 8-naphthalimide derivative as an Hg ²⁺ colorimetric probe in a solution.

The invention discloses application of the 1, 8-naphthalimide derivative as or in preparation of an Hg ²⁺ fluorescent switch.

The invention discloses an Hg ²⁺ detection sensor which comprises the 1, 8-naphthalimide derivative and a substrate, wherein the 1, 8-naphthalimide derivative is adsorbed on the substrate. The substrate is a conventional product such as filter paper, etc., and the specific adsorption operation (mode) is a conventional technology.

The invention discloses a method for detecting Hg ²⁺ in liquid, which comprises the following steps of mixing the 1, 8-naphthalimide derivative with the liquid, carrying out qualitative and quantitative analysis on Hg ²⁺ in the liquid according to the value of A ₅₂₅/A₄₃₅, or mixing the 1, 8-naphthalimide derivative with the liquid, carrying out qualitative and quantitative analysis on Hg ²⁺ in the liquid according to the fluorescence intensity at 550 nm, or dripping the liquid on a sensor containing the 1, 8-naphthalimide derivative, and carrying out qualitative and quantitative analysis on Hg ²⁺ in the liquid according to the color change of the sensor.

Positive effects and advantages compared with the prior art:

(1) The invention designs and synthesizes a novel 1, 8-naphthalimide derivative with a higher yield than similar products in literature;

(2) Realizing the multi-channel detection of Hg ²⁺ by one probe (Hg ²⁺ can be detected by colorimetric detection in a solution, hg ²⁺ can be identified by a portable sensor and can also be used as a Hg ²⁺ fluorescent switch);

(3) The test paper type portable sensor can be manufactured to recognize Hg ²⁺ with naked eyes;

(4) Picomolar hypersensitive response Hg ²⁺ can be achieved when the fluorescent switch is used as Hg ²⁺;

(5) The detection and identification process has good selectivity, sensitivity and strong anti-interference capability;

(6) The response to Hg ²⁺ is rapid and reversible.

Drawings

FIG. 1 is a schematic diagram showing the synthesis of 1, 8-naphthalimide derivatives BBNS, the chemical structural formulae of BBN compounds and BBNS according to the present invention.

FIG. 2 is an ultraviolet-visible absorption spectrum of BBNS before and after addition of 17 metal ions, where a is the absorption spectrum, b is the ratio of the absorbance of BBNS solution at 525 nm and 435 nm, solvent DMSO/H ₂ O (10/90, v/v), concentration BBNS is 10. Mu.M, and metal ion is 100. Mu.M.

FIG. 3 is a graph (b) of the linear relationship between the ultraviolet-visible absorption spectrum of BBNS at Hg ²⁺ concentration of 0-100. Mu.M, the ratio A ₅₂₅/A₄₃₅ of the absorbance of BBNS at 525 nm to 435 nm, and Hg ²⁺ concentration of 0,1, 3, 5, 7, 9, 10, 11, 13, 15, 17, 19, 20. Mu.M, solvent DMSO/H ₂ O (10/90, v/v), and concentration BBNS of 10. Mu.M.

FIG. 4 shows the effect of coexisting metal ions on the ratio A ₅₂₅/A₄₃₅ of maximum absorbance at 525 nm to 435 nm in DMSO/H ₂ O (10/90, v/v), at a concentration of BBNS of 10. Mu.M and of 20. Mu.M for each metal ion.

FIG. 5 is a plot of the time response of BBNS-Hg ²⁺ at a ratio A ₅₂₅/A₄₃₅ of absorbance at 525 nm to 435 nm in DMSO/H ₂ O (10/90, v/v), at a concentration of BBNS of 10. Mu.M and Hg ²⁺ of 20. Mu.M.

FIG. 6 is a photograph showing the Hg ²⁺ concentration using BBNS test paper, wherein the BBNS concentration is 0.265, 2.65, 13.25 mg/g, and the Hg ²⁺ concentration is 0,1, 10, 100, 1000. Mu.M from left to right.

FIG. 7 is a graph showing fluorescence emission spectra of BBNS solutions before and after 17 metal ions were added, solvent DMF/H ₂ O (1/99, v/v), concentration of BBNS at 10. Mu.M, metal ion at 100. Mu.M, excitation wavelength of 435 nm, slit width of 10 nm.

FIG. 8 is a graph (a) of fluorescence emission spectra of BBNS solutions containing different concentrations of Hg ²⁺ and the relationship between the fluorescence intensity at 550 and nm and the concentration of Hg ²⁺. Solvent DMF/H ₂ O (1/99, v/v), concentration BBNS of 10. Mu.M, hg ²⁺ concentration from top to bottom of 0, 100, 300, 500, 700, 900, 1000, 3000, 7000 pM (blue dot) 10, 30, 50, 70, 90 nM (green dot) 100, 150, 200, 250, 300 nM (red dot) 400, 500, 600 nM (black dot), excitation wavelength 435 nm, emission wavelength 550 nm, slit width 10 nm.

FIG. 9 shows the effect of coexisting metal ions on the maximum fluorescence intensity of BBNS-Hg ²⁺ at 550 nm in DMF/H ₂ O (1/99, v/v), concentration of BBNS at 10. Mu.M, various metal ions at 7000 pM, excitation wavelength of 435 at nm, slit width of 10 at nm.

FIG. 10 shows a test of the circularity of BBNS-Hg ²⁺ at 550 nm in DMF/H ₂ O (1/99, v/v), concentration BBNS being 10. Mu.M and Hg ²⁺ being 7000 pM. Excitation wavelength 435 nm, slit width 10 nm.

Detailed Description

The prior art reports a1, 8-naphthalimide derivative, the imide part of which is modified with a pyridine group, but the compound is an Ag ⁺ probe, has low response to Hg ²⁺ and can not be used as Hg ²⁺ probe. The invention designs and synthesizes a novel 1, 8-naphthalimide derivative (BBNS) with an aminothiazole structure at the 4-position. BBNS can recognize Hg ²⁺ in a multi-channel manner, can colorimetrically detect Hg ²⁺ in a solution, can be made into a test paper type portable sensor for recognizing Hg ²⁺ by naked eyes, and can be used as a hypersensitive Hg ²⁺ fluorescent switch with a response range reaching picomolar level. The synthesis method comprises the following steps:

The synthesis of intermediate BBN includes dissolving 4-bromo-1, 8-naphthalene anhydride in absolute ethyl alcohol, stirring and heating to 40-60 deg.C under the protection of N ₂, adding N-butylamine, reflux reacting for 15-30 hr, stopping reaction, cooling to room temperature, pouring into ice water, precipitating dark yellow precipitate, filtering, washing filter cake with deionized water, stoving and re-crystallizing with absolute ethyl alcohol to obtain yellowish crystalline solid.

Synthesis of 1, 8-naphthalimide derivative BBNS, mixing BBN (80 mg,0.24 mmol), cesium carbonate (78~156 mg,0.24~0.48 mmol), bis (triphenylphosphine) palladium (II) dichloride (PdCl ₂(PPh₃)₂ (25~50 mg,0.036~0.072 mmol) and triphenylphosphine PPh ₃ (20-39 mg, 0.075-0.15 mmol), heating, dropwise adding 2-aminothiazole (24~48 mg,0.24~0.48 mmol) dissolved in DMF by using a dropping funnel at a dropwise speed of 4-6 drops per minute, heating to 100-120 ℃ after dropwise adding, reacting for 1-3 hours, cooling the reaction mixture to room temperature, and heating at a rate of 10-15 ℃ per min, wherein the final reaction temperature is 100-120 ℃. The post-treatment is carried out by two methods, namely (1) adding 10 mL deionized water, mixing uniformly, extracting the mixed solution with dichloromethane (3X 10-3X 20 mL), collecting the lower solution, removing the solvent by rotary evaporation, and purifying the residue with petroleum ether/ethyl acetate (5/1, v/v) as a leaching agent and a silica gel column. (2) The reaction solution was transferred to a centrifuge tube and centrifuged, the supernatant was removed by rotary evaporation, and the residue was purified by a silica gel column using petroleum ether/ethyl acetate (5/1, v/v) as a eluting agent. The final brown yellow solid (BBNS) was 9.4-36.0. 36.0 mg in 11.1-42.9% yield.

The raw materials involved in the invention are all existing products, and specific preparation operation and performance test are conventional technologies. FIG. 1 is a schematic diagram showing the synthesis, BBN chemical structural formula and BBNS chemical structural formula of the 1, 8-naphthalimide derivative BBNS of the present invention.

The compound for preparing mercury ions is HgCl ₂ (AR, national pharmaceutical Condition chemical Co., ltd.) and the compound for preparing other metal ions is AlCl₃·6H₂O、FeCl₂·7H₂O、MgCl₂·6H₂O、CrCl₃·6H₂O、CuSO₄·5H₂O、Pb(CH₃COO)₂·3H₂O、CdCl₂·5H₂O、Ni(CH₃COO)₂·4H₂O、 anhydrous FeCl₃、MnSO₄·H₂O、CoCl₂·6H₂O、CaCl₂、KCl、AgNO₃、ZnCl₂、NaCl（AR, national pharmaceutical Condition chemical Co., ltd.).

The present invention mixes the metal compound with the solution system using conventional methods.

EXAMPLE preparation of intermediate (BBN)

Intermediate BBN synthesis, dissolving 4-bromo-1, 8-naphthalene anhydride (1.0 g,3.61 mmol) in absolute ethanol (15 mL) at room temperature, stirring and heating to 50 ℃ under the protection of N ₂, adding N-butylamine (0.75 mL,10.25 mmol), refluxing for 24 h, stopping the reaction, cooling to room temperature, pouring into 30 mL ice water, precipitating with dark yellow precipitate, filtering, washing the filter cake twice with deionized water, drying, and recrystallizing with absolute ethanol to obtain pale yellow crystalline solid 0.75 g with yield of 62.6%.

EXAMPLE two preparation of 1, 8-naphthalimide derivative (BBNS)

BBN (80 mg,0.24 mmol) was dissolved in DMF (3 mL), cesium carbonate (156 mg,0.48 mmol), pdCl ₂(PPh₃)₂ (50 mg,0.072 mmol) and PPh ₃ (39 mg, 0.15 mmol) were added under N ₂ protection, heating was started, 2-aminothiazole (24 mg,0.24 mmol) dissolved in 5mL DMF was added dropwise with a dropping funnel at a dropping rate of 4 to 6 drops per minute, and reaction 3 h was carried out at 120℃after completion of the dropwise addition. Cooling the reaction solution to room temperature, adding 10 mL deionized water, mixing, extracting with dichloromethane (3×10 mL), collecting lower solution, rotary evaporating to remove solvent, purifying the residue with petroleum ether/ethyl acetate (5/1, v/v) as eluent by silica gel column to obtain brown yellow solid (BBNS) 13 mg with yield of 15.5 %.¹H NMR（400 MHz,DMSO-d6,δ /ppm): 10.81(s,1H), 8.88(d, J=8.47 Hz, 1H), 8.80(d, J=8.13 Hz, 1H), 8.50(d, J=6.99 Hz, 1H), 8.43(d, J=8.59 Hz, 1H), 7.84(t, J=7.67 Hz, 1H), 7.48(d, J=3.09 Hz, 1H), 7.22(d, J=2.29 Hz, 1H), 4.02(t, J=7.44 Hz, 2H), 1.60(m, J=7.79 Hz, 2H), 1.33(m, J=6.99 Hz, 2H), 0.92(t, J=7.33 Hz, 3H).LC-MSm/z calcd. For C₁₉H₁₇N₃O₂S: 352.14 [M+H]⁺, found: 352.30.FT-IR: 1087.17(C-S-C),1237.27(C-N),1364.17,1388.91,1515.40,1566.98(ArH),1641.30(C=O),1692.41(C=N),2868.05,2921.73,2946.84(CH₃,CH₂),3296.47(NH).

Example preparation of tri-1, 8-naphthalimide derivative (BBNS)

BBN (80 mg,0.24 mmol) was dissolved in DMF (3 mL), cesium carbonate (78 mg,0.24 mmol), pdCl ₂(PPh₃)₂ (25 mg,0.036 mmol) and PPh ₃ (20 mg, 0.075 mmol) were added under N ₂ protection, heating was started, 2-aminothiazole (24 mg,0.24 mmol) dissolved in 5mL DMF was added dropwise with a dropping funnel at a dropping rate of 4 to 6 drops per minute, and reaction 3h was carried out at 120℃after completion of the dropwise addition. The reaction solution was cooled to room temperature, then 10mL deionized water was added and mixed well, the mixed solution was extracted with dichloromethane (3×10 mL), the lower layer solution was collected, the solvent was removed by rotary evaporation, and the residue was purified by silica gel column using petroleum ether/ethyl acetate (5/1, v/v) as a eluent to give a brown yellow solid (BBNS) 9.4 mg in 11.1% yield.

Example preparation of tetra 1, 8-naphthalimide derivative (BBNS)

BBN (80 mg,0.24 mmol) was dissolved in DMF (3 mL), cesium carbonate (156 mg,0.48 mmol), pdCl ₂(PPh₃)₂ (50 mg,0.072 mmol) and PPh ₃ (39 mg,0.15 mmol) were added under N ₂ protection, heating was started, 2-aminothiazole (24 mg,0.24 mmol) dissolved in 5mL DMF was added dropwise with a dropping funnel at a dropping rate of 4-6 drops per minute, reaction 1 h was carried out at 100℃after completion of the dropwise addition, and then 2-aminothiazole (15 mg,0.15 mmol) was added dropwise again, and reaction 1 h was continued. The reaction solution was cooled to room temperature, then 10 mL deionized water was added and mixed well, the mixed solution was extracted with dichloromethane (3×20 mL), the lower layer solution was collected, the solvent was removed by rotary evaporation, and the residue was purified by silica gel column using petroleum ether/ethyl acetate (5/1, v/v) as a eluent to give a brown yellow solid (BBNS) 15.3 mg in 18.2% yield.

EXAMPLE five preparation of 1, 8-naphthalimide derivative (BBNS)

BBN (80 mg,0.24 mmol) was dissolved in DMF (3 mL), cesium carbonate (156 mg,0.48 mmol), pdCl ₂(PPh₃)₂ (50 mg,0.072 mmol) and PPh ₃ (39 mg, 0.15 mmol) were added under N ₂ protection, heating was started, 2-aminothiazole (48 mg,0.48 mmol) dissolved in 5 mL DMF was added dropwise with a dropping funnel at a dropping rate of 4 to 6 drops per minute, and reaction 3h was carried out at 120℃after completion of the dropwise addition. The reaction solution was cooled to room temperature, then 10 mL deionized water was added and mixed well, the mixed solution was extracted with dichloromethane (3×20 mL), the lower layer solution was collected, the solvent was removed by rotary evaporation, and the residue was purified by silica gel column using petroleum ether/ethyl acetate (5/1, v/v) as a eluent to give a brown yellow solid (BBNS) 25.7 mg in 30.5% yield.

EXAMPLE preparation of hexa 1, 8-naphthalimide derivative (BBNS)

BBN (80 mg,0.24 mmol) was dissolved in DMF (3 mL), cesium carbonate (156 mg,0.48 mmol), pdCl ₂(PPh₃)₂ (50 mg,0.072 mmol) and PPh ₃ (39 mg, 0.15 mmol) were added under N ₂ protection, heating was started, 2-aminothiazole (48 mg,0.48 mmol) dissolved in 5mL DMF was added dropwise with a dropping funnel at a dropping rate of 4 to 6 drops per minute, and reaction 3 h was carried out at 120℃after completion of the dropwise addition. The reaction solution was cooled to room temperature, then transferred to a centrifuge tube for centrifugation, the solvent was removed by rotary evaporation of the supernatant, and the residue was purified by a silica gel column using petroleum ether/ethyl acetate (5/1, v/v) as a eluent to give a brown yellow solid (BBNS) 36.0: 36.0 mg in 42.9% yield.

EXAMPLE seven selectivity of BBNS for Metal ions in the DMSO/H ₂ O (10/90, v/v) System

As shown in FIG. 2a, hg ²⁺ significantly reduces the absorbance of BBNS solutions at 435 nm in DMSO/H ₂ O (10/90, v/v), enhances the absorption at 525 nm, and other metal ions have little effect on the absorption spectrum of BBNS. The ratio a ₅₂₅/A₄₃₅ of the absorbance of 17 metal ions at 525 nm and 435 nm was calculated and plotted on the ordinate with the metal ions on the abscissa (fig. 2 b), and Hg ²⁺ was found to increase a ₅₂₅/A₄₃₅ by a factor of 33.6 with the other metal ions having little effect on a ₅₂₅/A₄₃₅. BBNS showed a significant response to Hg ²⁺ in DMSO/H ₂ O (10/90, v/v), possibly as a ratiometric Hg ²⁺ colorimetric probe.

EXAMPLE eight relation of absorbance of BBNS in DMSO/H ₂ O (10/90, v/v) System to Hg ²⁺ concentration

The relationship between the ultraviolet-visible absorption spectrum and Hg ²⁺ concentration of BBNS DMSO/H ₂ O (10/90, v/v) solutions was further examined. From fig. 3a, as Hg ²⁺ is added, the absorbance of BBNS solution at 435 and nm gradually decreases, the absorbance at 525 and nm gradually increases, and the ratio a ₅₂₅/A₄₃₅ of absorbance at 525 and nm to 435 and nm is substantially stable as the Hg ²⁺ concentration increases to 20 μm. As shown in FIG. 3b, in the range of Hg ²⁺ concentration (0-20. Mu.M), A ₅₂₅/A₄₃₅ and Hg ²⁺ concentration show good linear relationship, the linear equation is A ₅₂₅/A₄₃₅=0.0252×[Hg²⁺ ] +0.0157, the correlation coefficient R ² is 0.99341, and the detection limit is 0.28. Mu.M.

Example nine influence of Co-existing Metal ion pair BBNS colorimetric detection of Hg ²⁺ in DMSO/H ₂ O (10/90, v/v) System

In order to examine the interference condition of the coexisting other metal ion pairs BBNS to detect Hg ²⁺, one of Ag⁺、Al³⁺、Ca²⁺、Cd²⁺、Co²⁺、Cr³⁺、Cu²⁺、Fe²⁺、Fe³⁺、K⁺、Mg²⁺、Mn²⁺、Na⁺、Ni²⁺、Pb²⁺、Zn²⁺ is respectively added into BBNS solution containing Hg ²⁺, the ultraviolet-visible absorption spectrum of the solution before and after the addition of the ions is compared, the ratio A ₅₂₅/A₄₃₅ of the absorbance at 525 nm and 435 nm is plotted against the metal ions, as shown in fig. 4, after the coexisting metal ions are added, the A ₅₂₅/A₄₃₅ of the system has no obvious change, and therefore, the system has better anti-metal ion interference capability when the Hg ²⁺ is detected by BBNS.

EXAMPLE ten time responsiveness of BBNS to Hg ²⁺ in the DMSO/H ₂ O (10/90, v/v) System

Next, the time response of BBNS to detection of Hg ²⁺ in DMSO/H ₂ O (10/90, v/v) system was studied, as shown in fig. 5, with a ₅₂₅/A₄₃₅ rising very quickly to near maximum within 3 minutes, and stabilizing substantially around maximum after 9 minutes. The BBNS has the function of rapidly detecting Hg ²⁺ in a DMSO/H ₂ O (10/90, v/v) system.

Example eleven BBNS practicality of detection of Hg ²⁺ as a colorimetric probe

To investigate the utility of BBNS, pond water and tap water from the university of su villa lake district were labeled at BBNS and the results are shown in table 1. The measured Hg ²⁺ concentration is close to the added Hg ²⁺ concentration, the recovery rate of Hg ²⁺ is between 101.7 and 109.6 percent, and the relative standard deviation of three parallel experiments is lower than 4.5 percent, so BBNS can effectively detect Hg ²⁺ in an actual environment water sample, and has better practicability.

Solvent system DMSO/H ₂ O (10/90, v/v), BBNS concentration 10. Mu.M, RSD relative standard deviation, detection method see example twelve.

Example twelve BBNS method for detecting Hg ²⁺ as colorimetric probe

Adding Hg ²⁺ to be measured into a DMSO solution of BBNS, fixing the volume by using DMSO and H ₂ O to ensure that the volume ratio of DMSO/H ₂ O is 10/90, wherein the concentration of BBNS is 10 mu M to obtain the to-be-measured solution, measuring the ultraviolet-visible absorption spectrum of the to-be-measured solution, finding A ₅₂₅ and A ₄₃₅, calculating A ₅₂₅/A₄₃₅, and calculating according to a linear equation A ₅₂₅/A₄₃₅=0.0252×[Hg²⁺ +0.0157 to obtain the concentration of Hg ²⁺ in the to-be-measured sample.

Preparation method of test paper of example thirteen BBNS

Samples BBNS of 3.53 mg and 8.83 mg were dissolved in 10mL and 5 mL ethanol, respectively, to give stock solutions with concentrations of 1 mM and 5mM, respectively, and the stock solution BBNS of 1 mL (1 mM) was again taken up in 10mL volumes and diluted 10 times with ethanol to prepare a stock solution of 0.1 mM. Cutting conventional filter paper into round paper sheets with the diameter of 0.6 cm, dripping 20 mu L of stock solution with the concentration of 0.1 (1 or 5) mM on the paper sheets as required, standing for 30 min at room temperature, putting into a vacuum drying oven, drying for 5min to obtain BBNS test paper which can be used for detection, and putting on a porcelain point drip tray for standby. The concentration of BBNS on the test paper is expressed in mass fraction as milligrams (mg) of BNAS adsorbed on per gram (g) of filter paper, 0.265 (2.65 or 13.25) mg/g. (the filter paper has an average weight of 0.002 g).

Example fourteen BBNS test paper as a portable sensor to indicate Hg ²⁺

To investigate whether BBNS is portable, BBNS was adsorbed onto filter paper to make a test paper for detection of Hg ²⁺. The test paper BBNS was added dropwise with DMSO/H ₂ O (10/90, v/v) solutions containing Hg ²⁺ at different concentrations, and the color of the test paper was observed to change immediately under natural light, and the photographic result is shown in FIG. 6. As the concentration of Hg ²⁺ increased, the colors of the test papers with BBNS concentrations of 0.265mg/g, 2.65mg/g and 13.25 mg/g were changed gradually from yellow to orange, so that the color changes of the BBNS test papers with three concentrations can be effectively indicated to Hg ²⁺ by naked eyes.

Example fifteen selectivity of BBNS fluorescence for Metal ions in DMF/H ₂ O (1/99, v/v) System

FIG. 7 is a graph showing fluorescence emission spectra before and after 17 metal ions are added to BBNS DMF/H ₂ O (1/99, v/v) solution. As can be seen, hg ²⁺ fluorescence quenches a DMF/H ₂ O (1/99, v/v) solution of BBNS, about 3.5 times as much as fluorescence quenching at wavelength 550 nm, thus demonstrating that BBNS may be useful as a quenching Hg ²⁺ fluorescent probe in DMF/H ₂ O (1/99, v/v) systems.

Example sixteen BBNS relationship between fluorescence and Hg ²⁺ concentration

When studying the relationship between the fluorescence intensity of BBNS DMF/H ₂ O (1/99, v/v) solution and the Hg ²⁺ concentration, it was found that the conventional concentrations of Hg ²⁺ of 1-10. Mu.M all completely quenched the fluorescence of the solution (FIG. 8a black panel curve). Reducing the concentration of Hg ²⁺, the effect of 100 nM-1 μm Hg ²⁺ on the BBNS fluorescence emission spectrum was studied, and it was found that even Hg ²⁺ of 100nM quenched about 3/4 of the fluorescence of BBNS (fig. 8a red set of curves). continuing to study the effect of Hg ²⁺ from 10-100 nM on the fluorescence emission spectrum of BBNS, hg ²⁺ from 10 nM was found to quench BBNS about 1/2 of the fluorescence (FIG. 8a Green set of curves). Further investigation of the effect of Hg ²⁺ of 100 pM-10 nM on the BBNS fluorescence emission spectrum, the fluorescence of BBNS gradually decreased with increasing Hg ²⁺ concentration (FIG. 8a blue panel curve). BBNS has achieved picomolar response to Hg ²⁺ and has hypersensitive properties. When Hg ²⁺ is changed from 0 to 7000 pM, the fluorescence intensity of BBNS drops almost linearly (dark blue dot arranged almost vertically in FIG. 8 b), and has a switching characteristic. Therefore, BBNS can be used as a hypersensitive Hg ²⁺ fluorescence switch in a DMF/H ₂ O (1/99, v/v) system.

Example seventeen coexisting metal ion pair BBNS Effect as a hypersensitive Hg ²⁺ fluorescent switch

In order to examine the interference condition of other coexisting metal ion pairs BBNS as a hypersensitive Hg ²⁺ fluorescent switch, one metal ion in Ag⁺、Al³⁺、Ca²⁺、Cd²⁺、Co²⁺、Cr³⁺、Cu²⁺、Fe²⁺、Fe³⁺、K⁺、Mg²⁺、Mn²⁺、Na⁺、Ni²⁺、Pb²⁺、Zn²⁺ is respectively added into BBNS solution containing Hg ^{2 +}, and the maximum fluorescence intensity changes of the solution before and after the addition of the ions are compared, as shown in FIG. 9, after the coexisting metal ions are added, the maximum fluorescence intensity of the solution has no obvious change, which indicates that the coexisting ions have little influence on BBNS as a hypersensitive Hg ²⁺ fluorescent switch.

Example eighteen BBNS cyclability as a hypersensitive Hg ²⁺ fluorescence switch

As shown in FIG. 10, BBNS had fluorescence in DMF/H ₂ O (1/99, v/v) solution (on), hg ²⁺ was added, the solution fluorescence was quenched (off), excess Na ₂ S was added, the fluorescence intensity of the solution was ramped back to near the fluorescence intensity before addition of Hg ²⁺ and Na ₂ S (on), hg ²⁺ was added, the solution fluorescence was quenched again (off), excess Na ₂ S was added, and the solution fluorescence was restored (on). It can be seen that BBNS has better circulability as a hypersensitive Hg ²⁺ fluorescent switch, and the amount of Na ₂ S is 10 nM (i.e. 10000 pM).

In summary, the application discloses a novel 1, 8-naphthalimide derivative, which can be used as a Hg ²⁺ colorimetric probe with high selectivity, high sensitivity and high anti-interference, a test paper type portable Hg ²⁺ sensor capable of observing indication results with naked eyes, and can also be used as a fluorescent switch for hypersensitive response to Hg ²⁺.

Claims (10)

1. A 1,8-naphthaleneimide derivative, the chemical structure of which is as follows: . 2. The method for preparing the 1,8-naphthalene imide derivative according to claim 1, characterized in that a BBN compound is reacted with 2-aminothiazole to obtain a 1,8-naphthalene imide derivative; the chemical structural formula of the BBN compound is as follows: . 3. The method for preparing 1,8-naphthaleneimide derivatives according to claim 2, characterized in that the reaction temperature is 100-150°C and the reaction time is 1-5 hours. 4. The method for preparing 1,8-naphthaleneimide derivatives according to claim 2, characterized in that the reaction is carried out in the presence of a noble metal catalyst, an inorganic base, an organic ligand, a solvent, and an inert gas. 5. The method for preparing 1,8-naphthaleneimide derivatives according to claim 4, characterized in that the noble metal catalyst comprises a palladium catalyst; the inorganic base comprises a cesium salt, a potassium salt, or a sodium salt; the organic ligand comprises a phosphine ligand; and the solvent is an organic solvent. 6. The method for preparing 1,8-naphthaleneimide derivatives according to claim 4, characterized in that the molar ratio of BBN compound, 2-aminothiazole, noble metal catalyst, inorganic base and organic ligand is 1:(1-2):(0.1-0.3):(1-2):(0.3-0.65). 7. Use of the 1,8-naphthaleneimide derivatives of claim 1 as or in the preparation of Hg ²⁺ colorimetric probes; or use of the 1,8-naphthaleneimide derivatives of claim 1 as or in the preparation of Hg ²⁺ fluorescent switches. 8. A Hg ²⁺ detection sensor, comprising the 1,8-naphthalimide derivative according to claim 1 and a substrate. 9. A method for detecting Hg ²⁺ in liquid for non-disease diagnosis, characterized in that the 1,8-naphthaleneimide derivative according to claim 1 is used as an active substance, and Hg ²⁺ in the liquid is detected by a colorimetric probe method, a fluorescent switch method or a sensor color change method. 10. The method for detecting Hg ²⁺ in a liquid for non-disease diagnosis according to claim 9, characterized in that it comprises the following steps: mixing the 1,8-naphthalene imide derivative according to claim 1 with a detection liquid, and performing qualitative and quantitative analysis of Hg ²⁺ in the detection liquid according to the value of the absorbance ratio A525/A435 at 525 nm and 435 nm; or mixing the 1,8-naphthalene imide derivative according to claim 1 with a detection liquid, and performing qualitative and quantitative analysis of Hg ²⁺ in the detection liquid according to the fluorescence intensity at 550 nm; or dropping the detection liquid on a sensor containing the 1,8-naphthalene imide derivative according to claim 1, and performing qualitative and quantitative analysis of Hg ²⁺ in the detection liquid according to the color change of the sensor.