METHOD FOR PREPARING HYDROPHOBIC COPPER NANOCLUSTERS-CONTAINING COLLOIDAL SOLUTION AND USE OF HYDROPHOBIC COPPER NANOCLUSTERS-CONTAINING COLLOIDAL SOLUTION IN DETECTING Fe3+

Abstract

Disclosed are a method for preparing a hydrophobic copper nanoclusters-containing colloidal solution and use of the hydrophobic copper nanoclusters-containing colloidal solution in detecting Fe.sup.3+. The hydrophobic copper nanoclusters-containing colloidal solution is prepared by dissolving Cu.sub.4I.sub.4 in dimethyl sulfoxide to obtain a solution of Cu.sub.4I.sub.4 in DMSO, and then performing self-assembly of the solution of Cu.sub.4I.sub.4 in DMSO with a EuW.sub.10 solution.

Claims

1-13. (canceled)

14. A method for preparing a hydrophobic copper nanoclusters-containing colloidal solution, comprising: mixing a solution of Cu.sub.4I.sub.4 in an organic solvent with an aqueous solution of EuW.sub.10 to obtain the hydrophobic copper nanoclusters-containing colloidal solution.

15. The method of claim 14, wherein a volume ratio of the solution of Cu.sub.4I.sub.4 in the organic solvent to the aqueous solution of EuW.sub.10 is in a range of (3-5):6.

16. The method of claim 14, wherein the organic solvent is dimethyl sulfoxide.

17. The method of claim 16, wherein a concentration of Cu.sub.4I.sub.4 in dimethyl sulfoxide is in a range of 0.0025-5 mg.Math.mL.sup.1.

18. The method of claim 14, wherein a concentration of EuW.sub.10 in water is in a range of 2-3 mg.Math.mL.sup.1.

19. The method of claim 14, wherein after mixing, in the hydrophobic copper nanoclusters-containing colloidal solution, a total concentration of EuW.sub.10 is in a range of 1-2 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 is in a range of 0.001-3 mg.Math.mL.sup.1.

20. The method of claim 14, wherein Cu.sub.4I.sub.4 is prepared by a process comprising: dispersing CuI in a dichloromethane solution, and stirring to be uniform; adding triphenylphosphine thereto, and fully stirring at room temperature, to obtain a first mixture; and subjecting the first mixture to suction filtration to obtain a white powdery solid; and adding the white powdery solid into an excessive acetonitrile solution, performing ultrasonic treatment to disperse the white powdery solid in the excessive acetonitrile solution to be uniform, removing excessive CuI, to obtain a second mixture, and subjecting the second mixture to suction filtration, to obtain a crude solid product, washing the crude solid product with acetonitrile, to obtain a first solid powder, dissolving the first solid powder in a dimethyl sulfoxide solution, standing for layering to obtain an upper layer, and adding dropwise a methanol solution to the upper layer, and diffusing for three days, to obtain the Cu.sub.4I.sub.4 powder.

21. The method of claim 20, wherein a concentration of CuI dispersed in the dichloromethane solution is in a range of 2-5 mmol L.sup.1, and a concentration of triphenylphosphine in the first mixture is in a range of 1-5 mmol L.sup.1.

22. The method of claim 20, wherein the ultrasonic dispersion is performed with an ultrasonic frequency of 30-50 kHz and an ultrasonic power of 80 W, and the ultrasonic dispersion is performed for 20-30 min.

23. The method of claim 20, wherein the process for preparing Cu.sub.4I.sub.4 comprises the following steps: dispersing CuI in the dichloromethane solution, and stirring for 10 min; adding triphenylphosphine thereto, and fully stirring at room temperature for 2 h, to obtain the first mixture; and subjecting the first mixture to suction filtration to obtain the white powdery solid; adding the white powdery solid into the excess acetonitrile solution, performing the ultrasonic treatment, removing excess CuI, to obtain the second mixture; subjecting the second mixture to suction filtration, to obtain the crude solid product; washing the crude solid product with acetonitrile to obtain the first solid powder, i.e., a pure white powdery solid; and dissolving 10 mg of the first solid powder in 2 mL of the dimethyl sulfoxide solution, to obtain the third mixture, adding the third mixture into the diffusion glass tube to obtain the upper layer, and adding dropwise 2 mL of the methanol solution to the upper layer, and diffusing for three days, to obtain the Cu.sub.4I.sub.4 powder.

24. The method of claim 14, wherein the method comprises: (1) preparation of a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide weighing a Cu.sub.4I.sub.4 powder, and adding dimethyl sulfoxide to the Cu.sub.4I.sub.4 powder to prepare the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide; (2) preparation of an aqueous solution of EuW.sub.10 weighing a EuW.sub.10 powder, and adding ultrapure water to the EuW.sub.10 powder to prepare the aqueous solution of EuW.sub.10; and (3) preparation of the hydrophobic copper nanoclusters-containing colloidal solution adding the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide and standing to obtain the hydrophobic copper nanoclusters-containing colloidal solution.

25. The method of claim 24, wherein the standing is performed for 1-3 days.

26. A method for detecting Fe.sup.3+, comprising using the hydrophobic copper nanoclusters-containing colloidal solution prepared by the method of claim 1 to detect Fe.sup.3+.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a molecular simulation diagram of Cu.sub.4I.sub.4 and EuW.sub.10 used in the present disclosure.

[0042] FIG. 2A shows a TEM image of the hydrophobic copper nanoclusters-containing colloid prepared in Example 1 of the present disclosure, and FIG. 2B shows a TEM image of the hydrophobic copper nanoclusters-containing colloid prepared in Example 2 of the present disclosure.

[0043] FIG. 3A shows an SEM image of the hydrophobic copper nanoclusters-containing colloids prepared in Example 1 of the present disclosure, and FIG. 3B shows an SEM image of the hydrophobic copper nanoclusters-containing colloids prepared in Example 2 of the present disclosure.

[0044] FIG. 4 shows optical photographs of the hydrophobic copper nanoclusters-containing colloidal samples prepared in Examples 2 to 7 of the present disclosure, in which: (a) represents Example 7, (b) represents Example 6, represents is Example 5, (d) represents Example 4, (e) represents Example 3, and (f) represents Example 2.

[0045] FIG. 5 shows an excitation and emission fluorescence spectrogram of the hydrophobic copper nanoclusters-containing colloid prepared in Example 2 of the present disclosure.

[0046] FIG. 6 shows fluorescence spectrograms of the hydrophobic copper nanoclusters-containing colloids prepared in Examples 3 to 8 of the present disclosure.

[0047] FIG. 7 shows optical photographs of the samples under the irradiation of an ultraviolet lamp with a wavelength of 365 nm in Test Example 1 of the present disclosure after adding different kinds of metal ions with the same concentration (50 mol mL.sup.1) into the hydrophobic copper nanoclusters-containing colloidal solution prepared in Example 1 of the present disclosure.

[0048] FIG. 8 shows fluorescence spectrograms of the hydrophobic copper nanoclusters-containing colloidal solutions prepared in Example 1 of the present disclosure added with different kinds of metal ions with the same concentration (50 mol mL.sup.1) in Test Example 1 of the present disclosure.

[0049] FIG. 9 is a histogram of the fluorescence intensity ratio (I/I.sub.0) at the wavelength of 550 nm of the hydrophobic copper nanoclusters-containing colloidal solution (after adding metal ions (I) and before adding metal ions (I.sub.0)) prepared in Test Example 1 of the present disclosure.

[0050] FIG. 10 shows optical photographs of the hydrophobic copper nanoclusters-containing colloidal solutions prepared in Example 1 of the present disclosure with different concentrations of Fe.sup.3+ under the irradiation of an ultraviolet lamp with a wavelength of 365 nm in Test Example 2 of the present disclosure.

[0051] FIG. 11 shows fluorescence spectrograms of the hydrophobic copper nanoclusters-containing colloidal solutions prepared in Example 1 of the present disclosure added with different concentrations of Fe.sup.3+ in Test Example 2 of the present disclosure.

[0052] FIG. 12 is a curve showing the variations of fluorescence intensity ratio (I.sub.0/I) at the wavelength of 550 nm before (I.sub.0) and after (I) adding different concentrations of Fe.sup.3+ in Test Example 2 of the present disclosure.

[0053] FIG. 13 shows an ultraviolet absorption spectrum of Fe.sup.3+ and an excitation spectrum of the hydrophobic copper nanoclusters-containing colloidal solution in Test Example 2 of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The present disclosure will be further described with reference to specific examples and the drawings but should not be limited thereto.

[0055] The raw materials used in the examples are all conventional raw materials and commercially available products, in which CuI is purchased from Shanghai Zhenxin Reagent Factory, China, triphenylphosphine is purchased from Adamas Reagent Company, all kinds of metal salts are purchased from Tianjin Kemiou Chemical Reagent Co., Ltd., China, and dimethyl sulfoxide i purchased from Sinopharm Group Chemical Reagent Co., Ltd, China.

Example 1

[0056] A method for preparing a hydrophobic copper nanoclusters-containing colloidal solution was performed as follows:

(1) Synthesis of Cu.sub.4I.sub.4

[0057] CuI (500 mg, 2.6 mmol) was dispersed in a dichloromethane solution, and they were stirred for 10 min. Triphenylphosphine (524 mg, 2.0 mmol) was added thereto and the resulting mixture was fully stirred at room temperature for 2 h, obtaining a first mixture. The first mixture was subjected to suction filtration, obtaining a white powdery solid. The white powdery solid was added to an excess acetonitrile solution and an ultrasonic treatment was then preformed. The excess CuI was removed, obtaining a second mixture. The second mixture was subjected to suction filtration, obtaining a crude solid product. The crude solid product was washed with acetonitrile, obtaining a first solid powder, i.e., a pure white powdery solid. 10 mg of the pure white solid powder was dissolved in 2 mL of a dimethyl sulfoxide solution, obtaining a third mixture. The third mixture was added to a diffusion glass tube, obtaining an upper layer. 2 mL of a methanol solution was added dropwise to the upper layer. After diffusing for three days, a Cu.sub.4I.sub.4 powder was obtained.

(2) Preparation of a Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0058] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 4 mg.Math.mL.sup.1.

(3) Preparation of an Aqueous Solution of EuW.SUB.10

[0059] A EuW.sub.10 powder was accurately weight. Ultrapure water was added thereto, preparing an aqueous solution of EuW.sub.10 with a concentration of 2.3 mg.Math.mL.sup.1.

(4) Preparation of a Hydrophobic Copper Nanoclusters-Containing Colloidal Solution

[0060] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 1.6 mg.Math.mL.sup.1, and the resulting mixture was stood for one day, obtaining the hydrophobic copper nanoclusters-containing colloidal solution.

Example 2

[0061] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 1, except that:

(4) Preparation of a Hydrophobic Copper Nanoclusters-Containing Colloidal Solution

[0062] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 1.6 mg.Math.mL.sup.1, and the resulting mixture was stood for two days, obtaining the hydrophobic copper nanoclusters-containing colloidal solution.

Example 3

[0063] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 2, except that:

(2) Preparation of a Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0064] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 5 mg.Math.mL.sup.1.

(4) Preparation of Copper Nanoclusters

[0065] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 2.0 mg.Math.mL.sup.1, and the resulting mixture was stood for two days.

Example 4

[0066] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 2, except that:

(2) Preparation of a Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0067] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 1 mg.Math.mL.sup.1.

(4) Preparation of a Hydrophobic Copper Nanoclusters-Containing Colloidal Solution

[0068] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 0.4 mg.Math.mL.sup.1, and the resulting mixture was stood for two days.

Example 5

[0069] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 2, except that:

(2) Preparation of a Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0070] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 0.5 mg.Math.mL.sup.1.

(4) Preparation of a Hydrophobic Copper Nanoclusters-Containing Colloidal Solution

[0071] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 0.2 mg.Math.mL.sup.1, and the resulting mixture was stood for two days.

Example 6

[0072] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 2, except that:

(2) Preparation of a Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0073] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 0.25 mg.Math.mL.sup.1.

(4) Preparation of Copper Nanoclusters

[0074] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 0.1 mg.Math.mL.sup.1, and the resulting mixture was stood for two days.

Example 7

[0075] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 2, except that:

(2) Preparation of Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0076] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 0.025 mg.Math.mL.sup.1.

(4) Preparation of a Hydrophobic Copper Nanoclusters-Containing Colloidal Solution

[0077] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 0.01 mg.Math.mL.sup.1, and the resulting mixture was stood for two days.

Example 8

[0078] The method for preparing a hydrophobic copper nanoclusters-containing colloidal solution in this example was preformed according to the procedures as described in Example 1, except that:

(2) Preparation of a Solution of Cu.sub.4I.sub.4 in Dimethyl Sulfoxide

[0079] The Cu.sub.4I.sub.4 powder was weighed. Dimethyl sulfoxide was added thereto, preparing a solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide with a concentration of 0.0025 mg.Math.mL.sup.1.

(4) Preparation of a Hydrophobic Copper Nanoclusters-Containing Colloidal Solution

[0080] The aqueous solution of EuW.sub.10 was taken and added to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide (with a volume ratio of the aqueous solution of EuW.sub.10 to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide being 6:4) such that a total concentration of EuW.sub.10 in the final system was 1.38 mg.Math.mL.sup.1 and a total concentration of Cu.sub.4I.sub.4 in the final system was 0.001 mg.Math.mL.sup.1, and the resulting mixture was stood for two days.

Test Example 1

[0081] 50 mol metal ions (Ca.sup.2+, Fe.sup.3+, Ba.sup.2+, Zn.sup.2+, Cu.sup.2+, Na.sup.+, Pb.sup.2+, Mg.sup.2+, Al.sup.3+, Ni.sup.2+, and K.sup.+) were weighed and added to the aqueous solution of EuW.sub.10 prepared in Example 1, and eddied for 1 min to mix evenly, obtaining a EuW.sub.10/metal ion solution.

[0082] The prepared EuW.sub.10/metal ion solution was transferred to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide prepared in Example 1, they were eddied for 10 s to mix evenly, and the resulting mixture was stood for 2 h. The sample was observed under an ultraviolet lamp with a wavelength of 365 nm. The optical photograph is shown in FIG. 7 (the anions countering metal ions were all nitrate).

[0083] The hydrophobic copper nanoclusters-containing colloidal solution and the samples added with different kinds of metal ions were transferred to quartz colorimetric utensil respectively, and the emission spectrograms of the samples were tested with a fluorescence spectrophotometer. The results are shown in FIG. 8. A histogram of the fluorescence intensity ratio (I/I.sub.0) at the wavelength of 550 nm of the hydrophobic copper nanoclusters-containing colloidal solution after adding metal ions (I) to that before adding metal ions (I.sub.0) is shown in FIG. 9.

[0084] Because of the transfer of ligand to metal charge, - interaction between ligands, and the addition of poor solvents, Cu.sub.4I.sub.4 molecules aggregates and the aggregation-induced luminescence occurs, so that the aggregations has good fluorescence properties. As can be seen from FIGS. 8 and 9, after adding metal ions, it can be found that only Fe.sup.3+ can completely quench the fluorescence. The addition of other metal ions has little effect on the fluorescence intensity. It shows that hydrophobic copper nanoclusters-containing colloidal solution prepared according to the present disclosure has high selectivity in detecting Fe.sup.3+, and the detection limit is 50 nM. This phenomenon can be observed with a portable ultraviolet lamp and fluorescence spectrum. The detection results are easy to observe and determine.

Test Example 2

[0085] Different amounts of Fe.sup.3+ were weight and added to the aqueous solution of EuW.sub.10 prepared in Example 1 and they were eddied for 1 min to mix evenly, obtaining a EuW.sub.10/Fe.sup.3+ solution. The prepared EuW.sub.10/Fe.sup.3+ solution was transferred to the solution of Cu.sub.4I.sub.4 in dimethyl sulfoxide prepared in Example 1, they were eddied for 1 min to mix evenly, and the resulting mixture was stood for 2 h. FIG. 10 shows an optical photograph of the hydrophobic copper nanoclusters-containing colloidal solution prepared in Example 1 according to the present disclosure with different concentrations of Fe.sup.3+ under the irradiation of an ultraviolet lamp with a wavelength of 365 nm.

[0086] The samples with different concentrations of Fe.sup.3+ were transferred to a quartz colorimetric utensil, and the emission spectrograms of the samples were tested with a fluorescence spectrophotometer. The results are shown in FIG. 11. A curve showing the variations of fluorescence intensity ratio (I.sub.0/I) at the wavelength of 550 nm of the hydrophobic copper nanoclusters-containing colloidal solution (before adding Fe.sup.3+ (I.sub.0) and after adding Fe.sup.3+ (I)) is shown in FIG. 12. An ultraviolet absorption spectrum of Fe.sup.3+ and an excitation spectrum of the hydrophobic copper nanoclusters-containing colloidal solution are shown in FIG. 13.

[0087] It can be seen from FIGS. 11 and 12 that with the increase of the concentration of Fe.sup.3+, the fluorescence intensity of the hydrophobic copper nanoclusters-containing colloidal solution prepared in Example 1 gradually decreases, and the fluorescence intensity ratio at the wavelength of 550 nm before adding Fe.sup.3+ (I.sub.0) and after adding Fe.sup.3+ (I) changes linearly, indicating that the detection of Fe.sup.3+ has good sensitivity.