KR102115850B1 - Colorimetric sensor containing Chrysoidine G compound for detecting cobalt ion - Google Patents

Abstract

The present invention relates to a cobalt ion (Co ^{2 +),} cobalt ion (Co ^{2 +)} detecting a colorimetric (Colorimetric) comprising a detection composition and the composition for a sensor including the Cri soy Dean G (Chrysoidine G) compound . Cri soy Dean G colorimetric sensor according to the present invention can be visually quickly cobalt ions detected in the field exhibits a good selectivity and sensitivity by a change in color to the cobalt ion (Co ^{2 +)} from a variety of metal ions, a reusable It works.

Description

Colorimetric sensor containing Chrysoidine G compound for detecting cobalt ion

The present invention relates to a cobalt ion (Co ^{2 +),} cobalt ion (Co ^{2 +)} detecting a colorimetric (Colorimetric) comprising a detection composition and the composition for a sensor including the Cri soy Dean G (Chrysoidine G) compound .

Selective chemical sensors for the detection of metal ions play an important role in pharmaceuticals, ecosystems and the environment, so the development of such detection reagents has received considerable attention. Among metals, cobalt plays an important role in the synthesis of hemoglobin and metabolism of iron, and is an important component of vitamin B ₁₂ and other biological compounds, which is important for organic organisms. However, overexposure to cobalt ions adversely affects humans and animals and causes various diseases and disorders such as heart disease, lung disease, dermatitis, and vasodilation such as asthma, cardiac output, and cardiac expansion. Therefore, it is important to detect trace cobalt ions in biological and environmental substances.

At present, the method for detecting trace amounts of cobalt ions (Co ^{+ 2)} being used a high-frequency inductively coupled plasma emission spectrometry, atomic absorption analysis, fluorescence analysis techniques and electrochemical methods. However, these methods have the disadvantage that complicated equipment, difficult sample preparation process and skilled technicians are required. In contrast, the method for detecting cobalt ions using color change is receiving a great deal of attention because of the advantage of being able to easily and easily check whether a target ion is detected.

Accordingly, there is an urgent need for a study on a colorimetric sensor capable of quickly detecting cobalt ions in the field through such color change.

KR Publication No. 10-2015-0023101

The present inventors searched for a method for detecting cobalt (Co ^{2 +} ) ions, and a Chrysoidine G colorimetric sensor exhibited excellent selectivity and sensitivity to cobalt ions (Co ^{2 +} ) among various metal ions, and color. Through the change, cobalt ions can be quickly detected with the naked eye in the field, and it is confirmed that reusability is possible, and the present invention has been completed.

Accordingly, the present invention is to provide a, cobalt ions (Co ^{+ 2)} for detecting a composition comprising a soy Dean Cri G (Chrysoidine G) compounds.

In addition, the present invention is to provide a method for detecting cobalt ions (Co ^{2 +} ), including; adding the composition to the test sample.

In addition, the present invention is to provide a colorimetric (Colorimetric) sensor for the detection of cobalt ions (Co ^{2 +} ) containing the composition.

In order to achieve the above object,

The invention provides, cobalt ions (Co ^{+ 2)} for detecting a composition comprising a soy Dean Cri G (Chrysoidine G) compounds.

In addition, the present invention provides a method for applying the cobalt ions (Co ^{+ 2)} detecting the composition for test sample; provides a method for detecting a cobalt ion (Co ^{+ 2)} comprising a.

The present invention also provides a cobalt ion, a cobalt ion (Co ^{+ 2)} detecting a colorimetric (Colorimetric) sensor comprising the composition (Co ^{+ 2)} detected.

Hereinafter, the present invention will be described in detail.

The invention provides, cobalt ions (Co ^{+ 2)} for detecting a composition comprising a soy Dean Cri G (Chrysoidine G) compounds.

Chrysodine G compound (4-phenylazo-m-phenylenediamine) is a basic azo dye that exhibits a yellow color, soluble in water and ethanol, and is mainly used for dyeing of various natural and synthetic fibers. In addition, it includes a diazo group and an aniline group, and these binding sites may serve to bind cobalt ions (Co ^{2 +} ). The chrysoidine G compound can each bind various metal ions such as Li ⁺ , Mn ^{2 +} , Cu ^{2 +} , Hg ^{2 +} , Mg ^{2 +} , Fe ²⁺ , Fe ^{3 +} and Al ^{3 +} in aqueous solvents, respectively. However, a color change does not appear, only the color change appears as a dark orange color appeared in the change in absorbance only if combined with the Co ^{+ 2} ion yellow. Therefore, the chestnut soy Dean G compound is excellent in color change cobalt ion selectivity to the (Co ^{+ 2)} material.

The chrysoidine G may have a concentration of 5 × 10 ^-5 M to 9 × 10 ^-5 M, and preferably 6.5 × 10 ^-5 M to 7.5 × 10 ^-5 M. According to one embodiment of the present invention, the chrysoidine G exhibited a remarkable color change from yellow to dark orange at a concentration in the range. That is, when the concentration of chrysodine G is more than 9 × 10 ^-5 M, the sensitivity to cobalt ions increases, but the difference in color change that can be visually recognized is small, and the concentration of chrysodine G is also If it is less than 5 × 10 ^-5 M, color change may hardly occur.

The Cri soy Dean G and cobalt ions (Co ^{+ 2)} is 1: it is desirable to combine in a molar ratio of 1: 1. The Cri soy Dean G includes the binding site of the early and dia aniline group, the bonding sites are bonded to the cobalt ion (Co ^{+ 2)} and the coordination 1: it is possible to form the composite of Fig.

The cobalt ions (Co ^{+ 2)} detecting composition may include a solvent in addition, the solvent used may be water or the like, C ₁ -C ₅ alcohol, specifically, be a mixture of water, methanol, ethanol, or their However, it is not limited thereto.

The cobalt ions (Co ^{+ 2)} pH of the detection composition is preferably in the neutral pH of 6 to 8. According to an embodiment of the present invention, when the pH of the composition is an acidic pH of less than 6, or a basic pH of more than 8, the chrysodine G compound retains the primary color almost without discoloration even when combined with cobalt ions. . These results indicate that the color change of the chrysodine G colorimetric sensor for cobalt ions can be observed with the naked eye under conditions of pH 6-8.

In addition, the present invention provides a method for applying the cobalt ions (Co ^{+ 2)} detecting the composition for test sample; provides a method for detecting a cobalt ion (Co ^{+ 2)} comprising a.

The detection method includes, for example, applying the composition to the test sample, spraying, dropping, adding, or immersing the test sample in the composition, such as cobalt present in the test sample in the field by a simple operation to contact the composition and the test sample. the presence of ions (Co ^{+ 2)} can be rapidly detected by a color change.

Specifically, first, the composition containing the chrysoidine G compound is brought into contact with the test sample to be tested. At this time, the test sample can be applied to all things that can be contaminated with cobalt, such as seawater, groundwater, surface water, soil, dash, and rainwater.

When cobalt is present in the sample upon contact between the composition and the test sample, a color change appears according to the colorimetric reaction of chrysodine G and cobalt contained in the composition. At this time, the color change appears from yellow to dark orange, and depending on the concentration of cobalt, the color change becomes more and more dark orange. That is, by using the composition of the present invention, it is possible to grasp the concentration of cobalt as well as the presence of cobalt in contaminants.

In addition, chrysoidine G in the composition can efficiently detect only cobalt without being nourished by other metal ions or other substances through specific selective reaction with cobalt among contaminants containing various metal ions and other substances. , The detection sensitivity for cobalt is also excellent, so that only cobalt can be efficiently detected.

The color change according to the colorimetric reaction of chrysodine G and cesium can also be observed with the naked eye, and the detection result is monitored and recorded through a portable device such as a portable camera or desktop scanner to more accurately determine the concentration of cobalt in the contaminants. You can also calculate.

The present invention also provides a cobalt ion, a cobalt ion (Co ^{+ 2)} detecting a colorimetric (Colorimetric) sensor comprising the composition (Co ^{+ 2)} detected.

The colorimetric sensor is suitable as a detecting sensor of the cobalt ion as it represents a specific only when combined with cobalt ions (Co ^{+ 2).} In addition, it does not require an expensive spectroscopy device and has the advantage of being able to easily check the presence or absence of cobalt ions through color change with the naked eye.

The colorimetric sensor can be constructed by impregnating chrysodine G on a substrate. Of course, the base material may be used as a component used as a normal base material such as ordinary paper, plastic, and fabric. In particular, in the present invention, cellulose, polyester, nonwoven fabric, etc. having flexible properties and easy handling may be used. .

The colorimetric sensor is a cobalt ion can be quickly detected within 3 seconds, the cobalt ion to represent a high sensitivity and the detection limit of the cobalt ion concentration of 0.5 to 5 ppm for a (Co ^{2 +).}

In addition, the colorimetric sensor has the advantage of being reusable. This is because when the chrysodine G colorimetric sensor complexed with cobalt ions is treated with a powerful chelating agent such as NaOH, the chrysoidin G compound is separated and forms a stable cobalt-NaOH complex. Therefore, the crosoidin G colorimetric sensor of the present invention is immediately reusable in the field and can be used as a molecular level sensing sensor using an on-off absorption intensity profile.

Cri soy Dean G colorimetric sensor according to the present invention can be visually quickly cobalt ions detected in the field exhibits a good selectivity and sensitivity by a change in color to the cobalt ion (Co ^{2 +)} from a variety of metal ions, a reusable It works.

1 is (a) the color change image of the chrysodine G (CG) colorimetric sensor according to the addition of various metal ions under visible light, (b) UV-Vis absorption spectrum of the CG colorimetric sensor according to the addition of various metal ions, And (c) CG colorimetric sensor showing selectivity to cobalt ions.
2 is a diagram showing the color change of the CG-Co ^{2 +} complex at (a) various pH ranges (2-12) and (b) the initial concentration of the CG colorimetric sensor using the UV-Vis spectrum. Here, each experiment was repeated three times.
Fig. 3 is a diagram showing the Job's plot obtained between the CG colorimetric sensor and cobalt. Here, the sum of the total concentrations of the CG colorimetric sensor and cobalt was 10 μM, and each experiment was repeated three times.
4 is a diagram showing an image of color change over time in a CG colorimetric sensor in the presence of cobalt. Here, the concentration of cobalt is 5 ppm, and the scale bar is 3 cm.
Figure 5 relates to the colorimetric titration of cobalt, CG colorimetric sensor according to the presence of a continuous concentration of cobalt (a) UV-Vis. Absorption change, (b) UV-Vis. It is a plot showing the change in intensity ratio ((A ₄₆₀ / A ₃₈₀ ), and (c) UV-Vis.absorption ratio versus cobalt concentration.
FIG. 6 shows reversible images between (a) CG colorimetric sensor and cobalt, and (b) UV-Vis repeated continuously during the on-off phased switch. It is a diagram showing the absorption profile.

Hereinafter, preferred embodiments are provided to help understanding of the present invention. However, the following examples are only provided to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

Example  One. Chrysodine  Cobalt detection using G colorimetric sensor

4-phenylazo-m-phenylenediamine (Chrysoidine G) was purchased from Sigma-Aldrich (USA), and a standard solution of cobalt was purchased from Kanto Chemical Co., Ltd. (Japan). In addition, copper and mercury standard solutions were purchased from CPI International Corporation (USA), lithium chloride, iron (II) chloride tetrahydrate, iron (III) chloride hexahydrate, magnesium (II) chloride hexahydrate, manganese (II) chloride The tetrahydrate, and aluminum (III) chloride hexahydrate were purchased from Sigma-Aldrich (USA). All reagents and chemicals were prepared using pure water with an resistance of 18 MΩ · cm as an analytical grade.

1-1. Chrysodine  Cobalt detection using G colorimetric sensor

180 mg of Chrysoidine G (CG) was dissolved in 100 mL water and diluted with distilled water to a final concentration of 7 × 10 ^-5 M. Then, a standard solution of cobalt was added to the aqueous solution of chrysodine G, followed by gentle shaking for 3 seconds. After the reaction, visually confirm the color change, and UV-Vis. Using an Infinite ® UV M200 spectrometer. Spectra were measured.

1-2. Optimization of colorimetric detection

To investigate the effect of pH, the pH solution was prepared by adjusting with 1N NaOH or 1N HCl, and the pH of the solution was measured with a SevenCompactTM pH / ion S220 meter. In addition, in order to determine the initial concentration of chrysodine G, chrysoidine G colorimetric sensors of initial concentrations 7 × 10 ⁻⁴ M, 7 × 10 ⁻⁵ M, and 7 × 10 ⁻⁶ M, respectively, were prepared.

Experimental Example  One. Chrysodine  Selectivity analysis of G colorimetric sensor

To analyze the detection behavior of Chrysodine G (CG) colorimetric sensor, visual colorimetric inspection and UV-Vis with the addition of various metal ions. The absorption spectrum was measured. The ability to selectivity for cobalt ions was determined using nitrates of cobalt that are physiologically and environmentally compatible. (a) Image of color change of CG colorimetric sensor upon addition of various metal ions under visible light, (b) UV-Vis absorption spectrum of CG colorimetric sensor upon addition of various metal ions, and (c) Cobalt of CG colorimetric sensor The selectivity to ions is shown in FIG. 1.

As shown in Fig. 1 (a), CG colorimetric sensor is ^{Li +, Mn 2 +, Cu} 2 +, Hg 2 +, Mg 2 +, Fe 2+, any color change in the presence of Fe ^{3 +} and Al ^{3 +} Did not show. However, it was selectively discolored into yellow to dark orange color in the presence of Co ^{+ 2.}

As shown in Figure 1 (b), UV-Vis of the CG colorimetric sensor. Spectrum is ^{Li +, Mn 2 +, Cu} 2+, Hg 2 +, Mg 2 +, Fe 2 +, Fe 3 + , and were not substantially changed in the presence of Al ^{+ 3.} However, UV-Vis in the presence of Co ^{+ 2.} A large change was observed in the intensity ratio of the spectrum ((A ₄₆₀ / A ₃₈₀ ), and as a result, a color change from yellow to dark orange was observed.

As shown in Fig. 1 (c), the CG colorimetric sensor coexists with Li ⁺ , Mn ^{2 +} , Cu ^{2 +} , Hg ^{2 +} , Co ²⁺ , Mg ^{2 +} , Fe ^{2 +} , Fe ^{3 +} and Al ^{3 +.} In the presence of, it showed high selectivity only for cobalt ions.

The results CG colorimetric sensor exhibits excellent sensitivity and selectivity with respect to cobalt ions (Co ^{+ 2)} without interference from other metal ions, shows that it is possible to detect the cobalt with the naked eye by a change in color in the aqueous state.

Experimental Example  2. pH  And Chrysodine  Analysis according to the initial concentration of G

Absorbance changes in various pH and CG initial concentration ranges were measured to investigate the effect of the initial concentrations of pH and CG in detecting cobalt ions (Co ²⁺ ) using a Chrysodine G (CG) colorimetric sensor. To obtain various pH, the pH solution was adjusted with 1N NaOH or 1N HCl, and the pH was measured with a SevenCompactTM pH / ion S220 meter. In addition, the initial concentrations of the CG colorimetric sensor were adjusted to 7 × 10 ^-4 M, 7 × 10 ^-5 M, and 7 × 10 ^-6 M.

Figure 2 shows the color change of the CG-Co ^{2 +} complex at (a) various pH ranges (2-12) and (b) the initial concentration of the CG colorimetric sensor using the UV-Vis spectrum.

As shown in FIG. 2 (a), the CG-Co ^{2 +} complex generated a color change in the range of pH 6-8. However, at pH 2, 4, 10, and 12, the primary color remained almost the same. These results indicate that the color change of the CG colorimetric sensor for cobalt ions can be observed with the naked eye under the optimum conditions of pH 6-8.

As shown in FIG. 2 (b), when the initial concentration of CG is 7 × 10 ⁻⁵ M, compared to 7 × 10 ⁻⁴ M and 7 × 10 ⁻⁶ M, a significant color change from yellow to dark orange is observed. Shown. That is, when the initial concentration of CG is high, the sensitivity to cobalt ions is increased, but the difference in color change perceived by the naked eye is small, and when the initial concentration of CG is too low, color change hardly occurs.

From the above results, the optimum pH range is 6 to 8, and it can be seen that when the initial concentration of CG is 7 × 10 ^-5 M, it is the most efficient concentration capable of visually recognizing color change.

Experimental Example  3. CG - Co ^{2 +}  Analysis of the stoichiometric binding of the complex

To determine the binding ratio between the Chrysodine G (CG) colorimetric sensor and the cobalt ion, a Job's plot was obtained, and the results are shown in FIG. 3. Here, had the total concentration of the CG colorimetric sensor and a cobalt ion (Co ^{2 +)} kept constant at 10μM, cobalt ions was continuously changing the concentration of the _{^{(Co 2 +) (X m}} = ([Co 2 +] / ( [Co ^{2 +} ] + [CG])).

3, when the cobalt ion has a molar fraction of up to 50%, UV-Vis. The absorption rate (A ₄₆₀ / A ₃₈₀ ) showed the largest change.

The results indicate that the CG colorimetric sensor and the cobalt ion have a binding ratio of 1: 1 when forming a complex .

Experimental Example  4. CG - Co ^{2 +}  Response time to complex monitoring  analysis

Fast response time is one of the most important factors for analytical devices that monitor in real time. Accordingly, a real-time imaging experiment was performed between the Chrysodine G (CG) colorimetric sensor and the cobalt ion. The color change image over time of the CG colorimetric sensor in the presence of cobalt is shown in FIG. 4. Here, the concentration of cobalt is 5 ppm, and the scale bar is 3 cm.

As shown in Figure 4, the color change of the CG colorimetric sensor occurred within seconds in the presence of cobalt ions. When 5 ppm concentration of cobalt ion was added to the CG colorimetric sensor solution, it gradually changed from yellow to dark orange in just 3 seconds.

The above results indicate that the CG colorimetric sensor of the present invention can detect cobalt with the naked eye quickly within just 3 seconds.

Experimental Example  5. Chrysodine  G for colorimetric sensor UV - Vis  Titration analysis

To assess the sensitivity of the Chrysodine G (CG) colorimetric sensor to cobalt ions, colorimetric titration experiments were performed for different cobalt concentrations of 0.1-50 ppm. (A) UV-Vis of the CG colorimetric sensor with the presence of a continuous concentration of cobalt. Absorption change, (b) UV-Vis. Absorption intensity ratio (A ₄₆₀ / A ₃₈₀ ) changes, and (c) UV-Vis. The linear plot between the ratio of absorption intensity to the concentration of cobalt is shown in FIG. 5.

As shown in Fig. 5 (a), as the concentration of cobalt ions gradually increased, the peak at 460 nm gradually became red-transitioned, and the peak at 380 nm gradually decreased. In addition, as the CG-Co ²⁺ complex was formed, one clear isoabsorption point appeared at 410 nm. The isoabsorption point indicates a clear conversion between the complex and the non-complex.

As shown in FIG. 5 (b), the absorption intensity ratio ((A ₄₆₀ / A ₃₈₀ ) showed a linear increase when the concentration of cobalt ions increased from 0.4 ppm to 1.0 ppm, and when the concentration of cobalt ions was 5 ppm. In addition, as shown in Fig. 5 (c), the absorption intensity ratio ((A ₄₆₀ / A ₃₈₀ )) for various cobalt concentrations was shown as a linear float (R ² = 0.97).

The above results indicate that the CG colorimetric sensor of the present invention has excellent detection limits for the cobalt concentration and can detect cobalt ions through color change with the naked eye.

Experimental Example  6. Chrysodine  Reversibility analysis for G colorimetric sensor

To evaluate the reusability of the chrysoidine G (CG) colorimetric sensor in the field, the reversibility of the CG colorimetric sensor was evaluated. To understand the affinity between the CG colorimetric sensor and cobalt ions in water at the molecular level, the CG colorimetric sensor detecting cobalt ions was treated with a strong chelating agent such as NaOH. Specifically, 2 ppm of cobalt ion was added to the aqueous solution of the CG colorimetric sensor to confirm the color change, and then 1N NaOH was added. Then, 1N HCl was added again to confirm the color change. The reversible image between (a) CG colorimetric sensor and cobalt according to the above process and (b) continuously repeated UV-Vis during on-off stepwise switch. The absorption profile is shown in FIG. 6.

As shown in FIG. 6, after the color change from yellow to dark orange was confirmed by adding 2 ppm of cobalt ion to the aqueous solution of the CG colorimetric sensor, color change from dark orange to yellow occurred when 1N NaOH was subsequently added. . This result is due to the formation of a stable cobalt-NaOH complex due to the addition of NaOH. Subsequently, when 1N HCl was added, a color change from yellow to dark orange occurred again. This reversible color change was repeated over and over again. Even when the reversible reaction was repeated 8 times, it was confirmed that the role faithfully performed as a colorimetric indicator without decreasing the color intensity.

The above results indicate that the CG colorimetric sensor of the present invention is immediately reusable in the field and can be used as a molecular level sensing sensor using an on-off absorption intensity profile.

Claims (9)

A composition for detecting cobalt ions (Co ²⁺ ) colorimetric, comprising a Chrysoidine G compound. According to claim 1,
The chrysodine G is a concentration of 5 × 10 ^-5 M to 9 × 10 ^-5 M, characterized in that the composition for colorimetric detection of cobalt ions (Co ²⁺ ). According to claim 1,
The chrysodine G and cobalt ions (Co ²⁺ ) is characterized in that it is combined in a molar ratio of 1: 1, cobalt ions (Co ²⁺ ) colorimetric composition. According to claim 1,
Cobalt ion (Co ²⁺ ) colorimetric detection composition comprising at least one solvent selected from the group consisting of water and C ₁ -C ₅ alcohols. According to claim 1,
Characterized in that the pH is 6 to 8, a composition for colorimetric detection of cobalt ions (Co ²⁺ ). Adding the composition for detecting cobalt ion (Co ²⁺ ) colorimetric of claim 1 to a test sample; And Observing the color change with the naked eye; including, colorimetric detection method of cobalt ion (Co ²⁺ ). A colorimetric sensor for detecting cobalt ions (Co ²⁺ ), comprising the composition for detecting cobalt ions (Co ²⁺ ) colorimetric of claim 1. The method of claim 7,
The colorimetric sensor has a detection limit of cobalt ion (Co ²⁺ ) concentration of 0.5 to 5 ppm, a colorimetric sensor for detecting cobalt ion (Co ²⁺ ). The method of claim 7,
The colorimetric sensor is characterized in that it can be reused, a colorimetric sensor for detecting cobalt ions (Co ²⁺ ).

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