KR100891171B1 - An Optical Sensor Having Selectively Chromogenic Character By Binding A Metal-Ion - Google Patents

Abstract

The present invention relates to an optical sensor characterized in that the light-emitting receptor compound comprising a rhodamine-based luminophore having a functional group that selectively binds to a metal cation is produced by binding to the surface of the silica support.

Optical sensor according to the present invention is to facilitate the recovery by a distinct nucleotide changes in the color change and the emission characteristics of the combination of metal ions, especially Hg ^2+, portable color measuring instrument for detecting a metal ion, especially Hg ^{+ 2} in the environmental field It is expected to have high applicability to colorimetric kit and fluorimetric kit.

Color development, luminescence, optical sensor, silica support, mesoporous silica, metal cation, mercury ion

Description

An Optical Sensor Having Selectively Chromogenic Character By Binding A Metal-Ion}

The present invention relates to an optical sensor having a selective color development for a metal cation, wherein the optical sensor is a silica support having a chromophore and luminescence including rhodamine-based light emission and a chromophore having a functional group that selectively binds to a metal cation. It is characterized by being manufactured by bonding to the surface.

Fluorescent molecules for use as sensors to detect transition metal or heavy metal ions such as mercury ions (Hg ^{2 +} ), copper ions (Cu ^{2 +} ), and lead ions (Pb ^{2 +} ) zinc ions (Zn ^{2 +} ) ) Is increasingly important as a means of quantitatively and qualitatively monitoring specific metal ions in various processes in the biological or environmental field (AJ Bryan, AP de Silva, SA de Silva, RADD Rupasinghe and KRAS Sandanayake, Biosensors) 1989, 4, 169; CC Woodroofe and SJ Lippard, J. Am. Chem. Soc. 2003, 125, 11458; SK Kim, SH Lee, JY Lee, RA Bartsch and JS Kim, J. Am. Chem. Soc. 2004 , 126, 16499; SK Kim, SH Kim, HJ Kim, SH Lee, SW Lee, J. Ko, RA Bartsch and JS Kim, Inorg.Chem. 2005, 44, 7866; SJ Lee, JH Jung, J. Seo, I. Yoon, K.-M. Park, LF Lindoy and SS Lee, Org.Lett. 2006, 8, 1641; MK Nazeeruddin, D. Di Censo, R. Humphry-Baker and M. Gratzel, Adv.Funct.Mater 2006, 16, 189; R. Metivier, I. Leray, B. Lebeau and B. Valeur, J. Mat er.Chem, 2005, 15, 2965; E. Coronado, JR Galan-Mascaros, C. Marti-Gastaldo, E. Palomares, JR Durrant, R. Vilar, M. Gratzel and Md. K. Nazeeruddin, J. Am. Chem. Soc. 2005, 127, 12351).

Recently, cation-based sensors based on host-guest chemistry have become increasingly important in the field of detecting specific species. In particular, since the light emitted from the luminophore can be detected even at very low concentrations, chemical sensors using luminescence are of great interest to you (H. Nohta, H. Satozono, K. Koiso, H. Yoshida, J. Ishida and M. Yamaguchi, Anal. Chem. 2000, 72, 4199; A. Okamoto, T. Ichiba and I. Saito, J. Am. Chem. Soc. 2004, 126, 8364).

Since studies on compounds incorporating rhodamine emitters can serve as sensors for detecting ions or biomolecules, many studies have been conducted in solution (V. Dujols, F. Ford and AW Czarnik, J. Am. Chem). Soc. 1997, 119, 7386; G. John, M. Mason, PM Ajayan and JS Dordick, J. Am. Chem. Soc. 2004, 126, 15012; Y.-K. Yang, K.-J.Yook and J. Tae, J. Am. Chem. Soc. 2005, 127, 16760; Y. Xiang and A. Tong, Org. Lett. 2006, 8, 1549; AE Albers, VS Okreglak and CJ Chang, J. Am. Chem. Soc. 2006, 128, 9640; H. Zheng, Z.-H. Qian, L. Xu, F.-F. Yuan, L.-D. Lan and J.-G. Xu, Org. Lett. 2006, 8, 859).

Recently, organic-inorganic materials have attracted attention as new methodologies for ion recognition and sensing. Inorganic materials such as receptor-immobilized SiO ₂ , Al ₂ O ₃ , TiO ₂ , have very important advantages as solid chemical sensors on non-uniform solid-liquids (AP Wight and ME Davis, Chem. Rev. 2002, 102, 3589; E. Topoglidis, CJ Campbell, E. Palomares and JR Durrant, Chem. Commun. 2002, 1518; C.-Y. Lai, BG Trewyn, DM Jeftinija, K. Jeftinija, S. Xu , S. Jeftinija and VS-Y. Lin, J. Am. Chem. Soc. 2003, 125, 4451; M. Numata, C. Li, A.-H. Bae, K. Kaneko, K. Sakurai and S. Shinkai, Chem. Commun. 2005, 4655; SJ Lee, SS Lee, MS Lah, J.-M. Hong and JH Jung, Chem. Commun. 2006, 4539; SJ Lee, SS Lee, JY Lee and JH Jung, Chem Mater. 2006, 18, 4713; SJ Son and SB Lee, J. Am. Chem. Soc. 2006, 128, 15974; E. Palomares, R. Vilar, A. Green and JR Durrant, Adv.Funct. 2004, 14, 111; T. Balaji, SA El-Safty, H. Matsunaga, T. Hanaoka and F. Mizukami, Angew. Chem. Int. Ed. 2006, 45, 7202). First, the highly purified receptor on a solid inorganic support is capable of detecting and extracting organic guest molecules, metal ions and anions from contaminated solutions. Organic-inorganic hybrid nanomaterials can be recovered through appropriate chemical treatment. Finally, functionalized nanomaterials bound to fluorophore groups or chromophores show high selectivity and high sensitivity in luminescence and adsorption properties due to their large surface area and well aligned pores compared to spherical structures. Thus, mesoporous silica as an inorganic support is of high interest due to its advantages of high surface area and uniform porosity (CT Kresge, ME Leonowicz, WJ Roth, JC Vartuli and JS Beck, Nature 1992, 359, 710; H. Yang, N. Coombs and GA Ozin, Nature 1997, 386, 692; D. Zhao, J. Feng, Q. Huo, N. Melosh, GH Fredrickson, BF Chmelka and GD Stucky, Science 1998, 279, 548; Y. Sakamoto, M. Kaneda, O. Terasaki, DY Zhao, JM Kim, G. Stucky and R. Ryoo, Nature 2000, 408, 449; JM Kim and GD Stucky, Chem. Commun. 2000, 1159; F. Kleitz, F Marlow, GD Stucky and F. Schuth, Chem. Mater. 2001, 13, 3587; MS Wong, JN Cha, K.-S. Choi, TJ Deming and GD Stucky, Nano Lett. 2002, 2, 583; M. Kruk, T. Asefa, M. Jaroniec and GA Ozin, J. Am. Chem. Soc. 2002, 124, 6383; M. Mamak, GS Metraux, S. Petrov, N. Coombs, GA Ozin and MA Green, J. Am. Chem. Soc. 2003, 125, 5161).

Despite the advantages of the organic-inorganic hybrid material as described above, there is a need for the development of a new optical sensor that exhibits a high adsorption characteristic for a particular cation, thereby exhibiting a significant color change and a change in luminescence properties.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical sensor for detecting metal cations that has a high adsorption force to metal cations and is easy to recover.

It is still another object of the present invention to provide an optical sensor for detecting metal cations with a significant change in color and light emission characteristics before and after metal cations are adsorbed.

Another object of the present invention is to provide an optical sensor having high applicability to a portable colorimetric kit and a fluorimetric kit in the environmental field.

The inventors have found that the optical sensor manufactured by combining a chromophoric receptor compound including a rhodamine chromophore on the surface of a silica support having a high surface area has a high adsorption capacity for metal cations, particularly mercury ions, and thus, a significant color change and It has been found to exhibit a change in luminescence properties and has come to complete the present invention.

Accordingly, the present invention relates to an optical sensor having both selective color development and luminescence with respect to a metal cation, wherein the optical sensor comprises a rhodamine-based luminophore having a functional group that selectively binds to a metal cation. It is characterized by being manufactured in combination with.

Hereinafter, the present invention will be described in more detail.

At this time, if there is no other definition in the technical terms and scientific terms used, it has a meaning commonly understood by those of ordinary skill in the art.

In addition, repeated description of the same technical configuration and operation as in the prior art will be omitted.

The optical sensor according to the present invention is characterized in that the light emitting receptor compound including a rhodamine-based luminophore having a functional group that selectively binds to a metal cation is produced by binding to the surface of the silica support.

The optical sensor according to the present invention, metal cations, e.g., ^{Hg 2 +, Zn 2 +,} Pb 2 + and Cu ^2+, shows properties of adsorption (or coupled), especially for a high adsorption capacity for Hg ^{2 +} (or Coupling force).

The optical sensor according to the present invention can be represented by the following structural formula 1.

[Formula 1]

[In Formula 1, R is a rhodamine-based luminophore, B is a silica support selected from silica nanotubes, silica nanospheres, silica particles, or mesoporous silica, and A ¹ and A ² are independently C1-C30 alkyl. And an unsaturated bond (-C = C-), an amide group (-NHCO-), a thioamide group (-NHCS-), a urea group (-NHCONH-), a thiourea group (-NHCSNH-), and a carbonyl group (-CO Or one or more selected from thiocarbonyl groups (-CS-) in the alkylene chain.]

The optical sensor according to the present invention exhibits a change in color and a luminescence property when a rhodamine-based compound is bound to adsorb or bond a metal cation, and particularly, a change in color development and luminescence properties for mercury ions is remarkable.

In the optical sensor according to the present invention, the rhodamine-based chromophore (R) preferably has the following structure.

[In the above structure, R ¹ to R ⁴ are independently hydrogen or an alkyl group of C ¹ to C 3, R ⁵ and R ⁶ are independently an alkyl group of C 1 to C 3, and R ¹² is hydrogen, a nitro group, a halogen element, a nitrile group, Is selected from C1-C7 alkyl group, C5-C10 aryl group, C6-C20 aralkyl group, or C1-C20 alkoxy group, n is an integer of 0-2, p is an integer of 1-4.]

In the optical sensor according to the present invention, a light emitting receptor compound including a rhodamine-based luminophore having a functional group selectively binding to a metal cation is prepared by binding to a silica support, and the light emitting receptor compound is a rhodamine-based luminophore, and a silica support. It is preferable to have a trialkoxysilyl group as a reactor for bonding with and selected from a compound represented by the following formula (1).

[Formula 1]

[In Formula 1, R ¹ to R ⁴ are independently hydrogen or an alkyl group of C1-C3, R ⁵ and R ⁶ are independently an alkyl group of C1-C3;

R ¹² is selected from hydrogen, nitro group, halogen element, nitrile group, C 1 -C 7 alkyl group, C 5 -C 10 aryl group, C 6 -C 20 aralkyl group or C 1 -C 20 alkoxy group;

n is an integer from 0 to 2 and p is an integer from 1 to 4;

A ¹ and A ² are independently C ¹ to C 30 alkylene, an unsaturated bond (-C = C-), an amide group (-NHCO-), a thioamide group (-NHCS-), and a urea group (-NHCONH-) At least one selected from thiourea group (-NHCSNH-), carbonyl group (-CO-), or thiocarbonyl group (-CS-) in the alkylene chain;

R ⁷ and R ⁸ are each independently a C1-C7 alkyl group.]

More preferably, the light emitting receptor compound used in the preparation of the optical sensor according to the present invention is selected from the following Chemical Formula 2.

[Formula 2]

[Wherein X is selected from oxygen atom (O) or sulfur atom (S), R ⁷ is C1 ~ C7 alkyl group, R ⁹ is hydrogen or methyl group, R ¹⁰ is hydrogen, methyl or ethyl group, R ¹¹ Is a methyl or ethyl group, n is an integer from 0 to 2, m and k are an integer from 0 to 10.]

As the silica support according to the present invention, silica nanotubes, silica nano spheres, silica particles, or mesoporous silica may be used. The more porous and wider the surface area, the better the bonding strength with the light-emitting receptor compound. It is more preferable because it has nanopores and high surface area regularly arranged.

The optical sensor according to the present invention is prepared by combining a chromophoric receptor compound including a rhodamine-based chromophore on the surface of a silica support having a high surface area, and exhibits a high adsorption capacity for metal ions, particularly mercury ions, and changes color and emission before and after adsorption. It is expected that the change of properties and the regeneration by base are easy, and thus it is applied to portable colorimetric kits and fluorimetric kits for detecting specific metal ions in the environment.

The present invention will be described in more detail with reference to the following Examples. However, the following examples are merely examples of the present invention, and the claims of the present invention are not limited thereto.

Preparation Example 1 Preparation of Luminescent Receptor Compound ( 1 ) Having a Rhodamine-based Luminophore

compound 2  of  Produce

A solution of rhodamine B (0.40 g, 0.84 mmol) and tris (2-aminoethyl) amine (TREN) (0.24 g, 1.68 mmol) in 20 ml of methanol under nitrogen was dried until 80 to pink. Heated to ° C. After the solution was cooled to room temperature, the solvent was evaporated under reduced pressure, and then CH ₂ Cl ₂ (100 mL) and water (200 mL) were added, and the organic layer was separated. The CH ₂ Cl ₂ layer was washed twice with water and anhydrous sodium sulfate was added to remove the water. After filtering the sodium sulfate, the solvent was removed under reduced pressure to give 0.40 g of compound 2 as a colorless oil (yield 85%).

IR (deposit from CH ₂ Cl ₂ solution on a NaCl plate, cm ⁻¹ ): 3352, 1683, 1515, 1515; FAB MS m / z (M ⁺ ) calcd 570.37, found 571.00; ¹ H NMR (CDCl ₃ , 200 MHz): δ 7.90 (m, 1 H), 7.46 (m, 2 H), 7.10 (m, 1 H), 6.43 to 6.29 (d, 6 H, J 1 = 8.8 Hz, J2 = 5.6 Hz), 3.39 to 3.28 (q, 8 H), 2.54 to 2.51 (t, 2 H), 2.37 to 2.21 (m, 6 H), 1.60 to 1.40 (br, s, 4 H), 1.20 to 1.13 (t, 12H, J = 6.90 Hz); ¹³ C NMR (CDCl ₃ , 50 MHz): 167.6, 153.4, 148.8, 132.2, 131.6, 128.9, 128.1, 123.7, 122.6, 108.1, 105.6, 97.6, 64.9, 56.8, 44.3, 39.5, 38.1, 12.5 ppm.

compound One  of  Produce

Compound 2 (160 mg, 0.28 mmol) and 3- (triethoxysilyl) propylisocyanate (0.15 g, 0.62 mmol) were dissolved in 10 mL of toluene and stirred under reflux for 24 hours under nitrogen. It was. After cooling the solution to room temperature, the solvent was removed under reduced pressure, CH ₂ Cl ₂ (100 mL) and water (200 mL) were added, and the organic layer was separated. The CH ₂ Cl ₂ layer was washed twice with water and anhydrous sodium sulfate was added to remove the water. After filtering sodium sulfate, the solvent was removed under reduced pressure to obtain a brown crude Compound 2, which was purified by column chromatography (silica gel, ethyl acetate / methanol = 100: 1) to give 150 mg of Compound 1 as a brown oil. (Yield 50%).

IR (deposit from CH ₂ Cl ₂ solution on a NaCl plate, cm ⁻¹ ): 3346, 2973, 1690, 1079; FAB MS m / z (M ⁺ ) calcd 1065.5, found 1065.0; ¹ H NMR (CDCl ₃ , 200 MHz): δ 7.90 (m, 1 H), 7.46 (m, 2 H), 7.10 (m, 1 H), 6.37 to 6.33 (m, 6 H), 5.10 (s, 2 H), 3.87 to 3.77 (q, 12 H), 3.36 to 3.29 (m, 8 H), 3.16 to 3.10 (m, 10 H), 2.33 (s, 4 H), 1.90 (s, 2 H), 1.60 (m, 4H), 1.28-1.13 (q, 30H), 0.70 (t, J = 8.79 Hz, 4H). ¹³ C NMR (CDCl ₃ , 50 MHz): 168.9, 158.7, 158.4, 153.5, 152.6, 148.8, 131.1, 128.7, 108.3, 104.8, 97.5, 66.3, 58.2, 54.2, 44.2, 42.7, 37.5, 23.8, 18.2, 12.4 , 7.5 ppm.

Example 1

As shown in FIG. 1, a chromophoric receptor compound (Compound 1 ) comprising a rhodamine-based chromophore prepared in Preparation Example 1 as a chromophoric receptor compound is bound to the surface of mesoporous silica to have selective adsorption to metal ions, particularly mercury ions. An optical sensor was produced in which a change in color and a change in luminescence properties were remarkable.

Mesoporous  Preparation of Silica

Tetraethyl orthosilicate (TEOS) as a surfactant at room temperature is dissolved in octadecyltrimethylammonium chloride (ODTMA) as a surfactant under strong acid conditions in 100H ₂ O: 7HCl: 0.02ODTMA: 0.03TEOS The molar ratio was added. The reaction was stored in a constant temperature oven maintained at 95 ° C. for 1 day, and the white precipitate was filtered and washed with water to obtain mesoporous silica.

Rhodamine  Compound is immobilized Mesoporous  Silica ( MSIR Manufacturing

20 mg (0.02 mmol) of the rhodamine-based compound 1 prepared in Preparation Example 1 was dissolved in 5 ml of anhydrous toluene, and 100 mg of mesoporous silica prepared above was added thereto, followed by stirring under reflux for 24 hours under nitrogen. The obtained solid was washed with methylene chloride and acetone to remove residual compound 1 to obtain 100 mg of mesoporous silica-immobilized rhodamine (MSIR) to which rhodamine-based compounds were immobilized.

IR (KBr pellet, cm ^-1 ): 3382, 2975, 1656, 1517

Example 2

Silica in which rhodamine-based compounds were immobilized in the same manner as in Example 1, except that commercially available silica (Merck silica gel 60, average particle diameter 105 µm, specific surface area 510.00 m ² / g) was used instead of mesoporous silica. 100 mg of particles (silica particle-immobilized rhodamine; SPIR) were obtained.

IR (KBr pellet, cm ^-1 ): 3326, 1634, 1554, 1063

The structure of the prepared MSIR was confirmed by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDX), FT-IR spectroscopy and luminescence photometry ( analysis using fluorophotometry).

In Figure 2 (a) is mesoporous silica (MS), (b) is a TEM image of mesoporous silica (MSIR) to which the rhodamine-based compound is immobilized. Referring to the TEM photograph of FIG. 2, it can be seen that the rhodamine-based compound has mesoporous channels having a hexagonal arrangement that is clearly well aligned before and after immobilization.

In addition, the mesoporous silica is shown in Figure 3 after the change of the surface area, the pore volume (pore volume) and the pore size (pore diameter) after the rhodamine-based compound is fixed. Figure 3 shows nitrogen adsorption-desorption isotherms (A) and Barrett-Joyner-Halenda (BJH) pore size data (B), where (a) is mesoporous silica and (b) is the result of MSIR. Referring to the literature, the Brunauer-Emmett-Teller (BET) surface area of mesoporous silica is 1119.72 m ² / g (S. Brunauer, PH Emmett and E. Teller, J. Am. Chem. Soc. 1938, 60, 309; IA Banerjee, L. Yu and H. Matsui, Proc. Natl. Acad. Sci. USA. 2003, 100, 14678) and the pore volume is 0.49 cm ³ / g and the BET surface area of MSIR from result (A) of FIG. This was 377.21 m ² / g and the pore volume was 0.26 cm ³ / g. The BJH pore sizes of mesoporous silica and MSIR were 2.246 nm and 2.155 nm, respectively (FIG. 3B). From the results of FIG. 3, it can be seen that MSIR has decreased surface area and pore size due to immobilization of the rhodamine-based compound.

In addition, IR analysis of mesoporous silica and MSIR showed mesoporous silica peaks at 3450, 1658 and 1084 cm ⁻¹ , while MSIR 3382, 2975, 2948, 1656, 1634, 1614, 1517 and 1084 cm Observed at ⁻¹ . In other words, new peaks originating from rhodamine-based compounds appeared at 2975, 2948, 1656, 1634, 1614, and 1517 cm ⁻¹ , indicating that the rhodamine-based compound was firmly immobilized on the surface of the mesoporous silica.

Thermogravimetric analysis (TGA) was carried out to compare the porosity and binding strength of the MSIR prepared in Example 1 and the SPIR prepared in Example 2, and the results are shown in FIG. 4. Referring to the results of FIG. 4, the content of rhodamine-based compound 1 was 8.1 wt% for SPIR, and 23.1 wt% for MSIR. This is because the surface area (510.00 m ² / g) of commercially available silica particles has a significantly smaller value than mesoporous silica (1119.72 m ² / g).

Test Example 1 Measurement of Luminescence of MSIR by Coupling with Metal Ion

The intensity of luminescence emitted before and after the binding of MSIR to the metal cation was measured. Fluorescence emission and UV-VIS spectra were used for analyzers RF-5301-PC and S-2130, respectively, and the emission intensity measurement wavelength was 520 nm, and the excitation and emission slit widths were 1.5. nm. As the metal cation, a metal perchlorate salt solution (0.01 M in CH ₃ CN) was used.

FIG. 5 shows the emission of luminescence emitted after addition of a metal perchlorate solution (0.01 M in CH ₃ CN) to an MSIR suspension (0.09 mM in CH ₃ CN) to adjust the concentration of the metal salt to 2.25 mM and excitation at 520 nm. This is the result of measuring the intensity. CH ₃ CN suspension of MSIR is colorless and when, but to the light emitting Hg ^{+ 2} is added MSIR suspension is the center wavelength is emitted from a strong light emission 588nm. 10, it can be seen that the color of the MSIR suspension is changed from colorless to pink. These results pink colorless by induction with a rhodamine compound is very ball liquefied rhodamine compound through a ring-opening reaction of spiro lactam (spirolactam) ring present in the rhodamine compounds by interaction of Hg ^{2 +} binding in MSIR surface It is judged to increase not only the color change but also the light emission intensity.

For SPIR even if the Hg ^{+ 2} is added and the color changed to pink, it was also shown the trends similar MSIR a result of measuring the intensity of light emission (Fig. 6). However, when comparing the result of FIG. 6 with the result of MSIR (FIG. 5), it can be seen that the intensity of light emission is relatively low. An optical sensor that detects the MSIR Hg ^{+ 2} From these results it can be expected that the higher the applicability in the environmental field.

In the presence of Hg ^{+ 2} is added while changing the Hg (ClO _{4) 2} with 0-30 equivalents of the CH ₃ CN suspension MSIR of 0.09mM to determine the reason for the change in light emission of MSIR The evaluation results of the absorption and emission characteristics 7 is shown. Referring to the result of FIG. 7, it can be seen that as Hg ^{2 +} is added, a new light absorption band appears at 550 nm, and the emission intensity at 588 nm increases as the amount of addition thereof increases. This is determined by since the Hg ^{+ 2} to induce structural changes in the loader mingye compound 1.

In addition, FT-IR analysis to confirm the binding mode of Hg ^{2 +} and MSIR is shown in Figure 8 (MSIR: black, MSIR. Hg ^{2 +} complex: blue). Referring to the results of FIG. 8, the carbonyl (C═O) stretching of the spirolatamtam ring of MSIR was 1656 cm ⁻¹ , and the MSIR · Hg ^{2 +} complex was found to move toward the lower side.

MSIR recovered from the viewpoint of tetrabutylammonium hydroxide in MSIR · Hg ^{+ 2} complex (TBA ⁺ OH ^-) the results of the addition are shown in the Fig. Hg ^{2 +} (2.25 mM) MSIR suspension (0.09 mM in CH ₃ CN) in which is present (TBA ⁺ OH ^-) after a 520nm here (excitation) is added while changing the concentration of the measured intensity of the emitted luminescence . Base (OH ^-) in accordance with the added MSIR · Hg ^{2 +} complex of it was confirmed that the light emission is reduced gradually, even in the results of the 10 base (OH ^-) in accordance with the addition of MSIR · Hg ^{2 +} the color of the complex solution was pink You can see that it turns colorless again. From the results of FIGS. 9 and 10, it was found that the color and luminescence of MSIR were off-on-off by metal ions and bases, which is illustrated in FIG. 11. When applied to, it shows that it can be effectively reproduced and used.

Test Example 2 Adsorption ability of MSIR and SPIR to metal ions

CH ₃ CN solution containing metal nitrate (2.0 × 10 ^-4 mM) and MSIR or 10 mg of SPIR were mixed at room temperature for 10 minutes, filtered and the concentration of metal ions present in the organic phase was determined by ion chromatography (DX -500, DIONEX) is shown in Figure 8 the adsorption force with the metal ion. Referring to the results in FIG. 12, MSIR SPIR and was found to adsorb the Hg ^{+ 2,} 70% and 40%, respectively. That is, MSIR it can be seen that more favorable as an adsorbent to separate Hg ^{2 +} compared to the SPIR. The other metal ions, that is, Zn ^{+ 2,} the attraction force on MSIR Pb ^{2 +,} Cu ^{2 +,} and was found to be not more than 4 to 11%.

Test Example 3 Preparation of Glass Substrate Coated with MSIR

MSIR suspension (0.09 mM in CH ₃ CN) in the Hg ^{+ 2} and then by changing the concentration to prepare a suspension MSIR coated on each of them the glass substrate (20 mm x 50 mm) was formed a coating layer of MSIR 50㎛ thickness of the produced A photo of the substrate is shown in FIG. 13. In Figure 13 a) is Hg ^{2 +} is not added, b), c), d) is the concentration of Hg ^{2 +} 1.0 x 10 ^-5 M, 1.0 x 10 ^-4 M and 1.0 x 10 ^{-3, respectively} M. FIG. As the concentration of Hg ^{2 +} increase from the results of the 11 it can be seen that the pink of the glass substrate which is more vivid.

From the results of the above examples and test examples, the optical sensor manufactured by combining the light-receptor compound containing a rhodamine-based chromophore on MSIR or SPIR showed high selectivity in adsorption power and intensity of luminescence for metal ions, in particular Hg ²⁺ . in particular, MSIR show a high adsorption capacity of 70% for Hg ^{2 +} showed a better selectivity than the SPIR showed adsorption of 40%.

1 is a schematic diagram showing a manufacturing process of a silica support on which a rhodamine-based compound is immobilized as an example of an optical sensor according to the present invention.

2 is a TEM photograph (a) is mesoporous silica (MS), (b) is a photograph of mesoporous silica (MSIR) to which the rhodamine-based compound is immobilized.

3 shows nitrogen adsorption-desorption isotherms (A) and Barrett-Joyner-Halenda (BJH) pore size data (B), where (a) is mesoporous silica and (b) is the result of MSIR.

4 is a thermogravimetric analysis (TGA) result of silica particles (SPIR) immobilized with MSIR and rhodamine-based compounds.

Figure 5 shows the emission spectrum of the MSIR suspension with the addition of various metal ions.

Figure 6 shows the emission spectra of the SPIR suspension with the addition of various metal ions.

7 is a result of evaluating the absorption and emission characteristics of the MSIR suspension according to the amount of Hg ^{2 +} addition.

8 is an FT-IR analysis of the MSIR before and after being combined with the Hg ^{+ 2.}

9 is tetrabutylammonium hydroxide in MSIR · Hg ^{+ 2} complexes ^- the result of the addition of measuring the intensity of light emission (TBA ⁺ OH).

10 is a photograph showing the change in color and luminescence according to the addition of Hg ^{2 +} and base (OH ⁻ ) to MSIR.

11 is Hg ^{+ 2} addition and the base (OH ^-) in MSIR a schematic view showing the structural change of a rhodamine compound bonded to a silica support according to the addition.

12 is a graph showing the results of measuring the degree of metal ion adsorption of MSIR and SPIR using ion chromatography.

Figure 13 is a photograph of a glass substrate was prepared by changing the concentration of the suspension MSIR Hg ^{2 +} by coating them MSIR the coating layer formed.

Claims (7)

An optical sensor represented by the following Structural Formula 1, wherein a light emitting receptor compound including a rhodamine-based luminophore having a functional group selectively binding to a metal cation is prepared by binding to a surface of a silica support to simultaneously exhibit selective luminescence and color development with respect to a metal cation. [Formula 1]

[In Formula 1, R is a rhodamine-based luminophore, B is a silica support selected from silica nanotubes, silica nanospheres, silica particles, or mesoporous silica, and A ¹ and A ² are independently C1-C30 alkyl. And an unsaturated bond (-C = C-), an amide group (-NHCO-), a thioamide group (-NHCS-), a urea group (-NHCONH-), a thiourea group (-NHCSNH-), and a carbonyl group (-CO Or one or more selected from thiocarbonyl groups (-CS-) in the alkylene chain.] delete The method of claim 1, The rhodamine-based luminophore (R) has the following structure.

[In the above structure, R ¹ to R ⁴ are independently hydrogen or an alkyl group of C ¹ to C 3, R ⁵ and R ⁶ are independently an alkyl group of C 1 to C 3, and R ¹² is hydrogen, a nitro group, a halogen element, a nitrile group, Is selected from C1-C7 alkyl group, C5-C10 aryl group, C6-C20 aralkyl group, or C1-C20 alkoxy group, n is an integer of 0-2, p is an integer of 1-4.] The method of claim 1, The light-emitting receptor compound comprising a rhodamine-based luminophore having a functional group that selectively binds to the metal cation is represented by the following formula (1). [Formula 1]

[In Formula 1, R ¹ to R ⁴ are independently hydrogen or an alkyl group of C1-C3, R ⁵ and R ⁶ are independently an alkyl group of C1-C3; R ¹² is selected from hydrogen, nitro group, halogen element, nitrile group, C 1 -C 7 alkyl group, C 5 -C 10 aryl group, C 6 -C 20 aralkyl group or C 1 -C 20 alkoxy group; n is an integer from 0 to 2 and p is an integer from 1 to 4; A ¹ and A ² are independently C ¹ to C 30 alkylene, an unsaturated bond (-C = C-), an amide group (-NHCO-), a thioamide group (-NHCS-), and a urea group (-NHCONH-) At least one selected from thiourea group (-NHCSNH-), carbonyl group (-CO-), or thiocarbonyl group (-CS-) in the alkylene chain; R ⁷ and R ⁸ are each independently a C1-C7 alkyl group.] The method of claim 4, wherein The light-emitting receptor compound comprising a rhodamine-based chromophore having a functional group that selectively binds to the metal cation is an optical sensor, characterized in that selected from the formula (2). [Formula 2]

[Wherein X is selected from oxygen atom (O) or sulfur atom (S), R ⁷ is C1 ~ C7 alkyl group, R ⁹ is hydrogen or methyl group, R ¹⁰ is hydrogen, methyl or ethyl group, R ¹¹ Is a methyl or ethyl group, n is an integer from 0 to 2, m and k are an integer from 0 to 10.] The method according to any one of claims 1 and 3 to 5, Metal cation is Hg ²⁺ optical sensor, characterized in that. The method of claim 6, The silica support is mesoporous silica.

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