CN103018238B - Method for measuring iodide ions quickly and efficiently - Google Patents

Abstract

The invention provides a fast and efficient determination method for iodide ions. Using metal nanomaterials (gold or silver) with good water solubility and large molar absorptivity as probes, a new type of iodide ion sensor was established by using the inhibition effect of iodide ions on the oxidation and aggregation of nanomaterials. The method can be successfully applied to the determination of iodide ion, and the minimum concentration of iodide ion can be detected as low as 1nM by visual method. Compared with the currently reported methods for the determination of iodide ions (such as spectroscopic methods, electrochemical methods), this lowest concentration (1nM) is at least an order of magnitude lower than the detection limits obtained by these methods. The novel "anti-aggregation" nanometer material probe established by the invention can effectively avoid aggregation caused by other factors in the solution, and can improve the selectivity of determination. Therefore, the method has the advantages of simplicity, rapidity, high sensitivity and good selectivity, and is expected to be applied to the determination of iodide ions in table salt and urine.

Description

A Rapid and Efficient Detection Method for Iodide Ion

Technical field:

The invention relates to the field of analysis and detection, in particular to the application of water-soluble, high-absorptivity metal nanomaterials as colorimetric probes in rapid and highly sensitive detection of iodide ions.

Background technique:

Iodide ions are ubiquitous in the ecosystem and play a vital role in the growth and development of nerves and the metabolism of organisms [G.Aumont and JCTressol, Analyst, 1986, 3, 841-843; M.Haldimann, B.Zimmerli , C. Als and H. Gerber, Clin. Chem., 1998, 44, 817-824; F. Jalali, MJ Rajabi, G. Bahrami and M. Shamsipur, Anal. Sci., 2005, 21, 1533-1535]. For example, iodine deficiency can lead to spontaneous abortion, increased infant mortality, mental retardation [L.Rong and T.Takeuchi, J. Chromatogr.A, 2004, 1042, 131-135; J.Jakmunee and K.Grudpan, Anal. Chim. Acta, 2001, 438, 299-304; F. Delange, B. Benoist, E. Pretell and JT Dunn, Thyroid, 2001, 11, 437-447]. The World Health Organization has issued a statement that iodine deficiency is the leading cause of mental retardation worldwide [ http://www.iccidd.org ]. Therefore, the detection of iodide ion is of great significance and urgency. However, it is well known that halogen elements include fluorine, chlorine, bromine, and iodine. They have similar physical properties. Moreover, iodide ion has larger ionic radius, lower charge density and hydrogen bond forming ability. These characteristics have greatly increased the difficulty of selective determination of iodide [Z.Rodriguez-Docampo, SIPascu, S.Kubik and S.Otto, J. Am.Chem.Soc., 2006, 128, 11206-11210; M.Vetrichelvan , R.Nagarajan and S.Valiyaveettil, Macromolecules, 2006, 39, 8303-8310; N.Narinder Singh and DOJang, Org.Lett., 2007, 9, 1991-1994; S.Kubik, Chem.Soc.Rev., 2010, 39, 3648-3663]. Currently reported assay methods include spectroscopic methods [MP Arena, MD Porter and JS Fritz, Anal. 131, 1255-1259; ZBShang, Y. Wang and WJJin, Talanta, 2009, 78, 364-369; M. Zhang and BCYe, Chem. Commun., 2012, 48, 3647-3649; XJWang, CH Zhang, LHFeng and LW Zhang, Sens.Actuators, B, 2011, 156, 463-466; YMChen, TLCheng and WLTseng, Analyst, 2009, 134, 2106-2112; P. Pienpinijtham, XX Han, S.Ekgasit and Y. Ozaki, Anal.Chem., 2011 , 83, 3655-3662], electrochemical method [D.Phokharatkul, C.Karuwan, T.Lomas, D.Nacapricha, A.Wisitsoraat and A.Tuantranont, Talanta, 2011, 84, 1390-1395; L.Vitali, BL Horst, M. Heller, V T Fávere and G. A. Micke, J. Chromatogr. A, 2011, 1218, 4586-4591; H. Ciftci and U. Tamer, Anal. Chim. Acta, 2011, 687, 137-140]. In the field of spectrometry, supramolecular compounds are mostly used to determine iodide [A.Kumar, RKChhatra and PSPandey, Org.Lett., 2010, 12, 24-27; HHWang, L.Xue and H.Jiang, Org.Lett., 2011, 13, 3844-3847; MATetilla, M.Carla Aragoni, M.Arca, C.Caltagirone, C.Bazzicalupi, A.Bencini, A.Garau, F.Isaia, A.Laguna, V. Lippolis and V.Meli , Chem.Commun., 2011, 47, 3805-3807]. Although these sensors have good selectivity, there are also some defects. For example, the synthesis of supramolecular compounds involves relatively complicated organic synthesis steps, and the cost of reagents used is high; moreover, supramolecular compounds are often insoluble in water, and it is difficult to directly detect them in water. Determination of iodide ions; the detection limit of iodide ions with supramolecular compounds is often relatively high. Therefore, it will still be a challenge to establish novel and highly efficient iodide ion sensors.

Due to the advantages of being visible to the naked eye, easy to observe and not requiring advanced instruments, colorimetry is more and more used in the identification and detection of analytes [J.Liu and Y.Lu, J.Am.Chem.Soc ., 2005, 127, 12677-12683; C.J.Murphy, A.M.Gole, J.W.Stone, P.N.Sisco, A.M.Alkilany, E.C.Goldsmith and S.C.Baxter, Acc.Chem.Res., 2008, 41, 1721-1730; Y. Tan, X.Su, E.Liu and J.S.Thomsen, Anal.Chem., 2010, 82, 2759-2765; N.Nath and A.Chilkoti, Anal.Chem., 2002, 74, 504-509]. However, compared with supramolecular sensors, there are very few reports on metallic nanomaterial sensors for iodide ion determination. At present, there is only one literature that reports the determination of iodide ion by metal nanomaterial colorimetry. The measurement principle is to use the atomic recombination effect of iodide ions on CuAu core/shell nanomaterials [J.Zhang, X.W.Xu, C.Yang, F.Yang and X.R.Yang, Anal.Chem., 2011, 83, 3911-3917] . The invention utilizes the anti-aggregation effect of the iodide ion on the metal nanometer material to establish a new test method for the iodide ion. Using the anti-aggregation principle to measure can effectively avoid the interference of nanometer material aggregation caused by other factors in the solution, and the selectivity of the determination is greatly improved. The method can successfully realize the rapid and efficient determination of iodide ions, and the common anions hardly interfere with the determination of iodide ions. This method is expected to be used for the determination of iodide ions in table salt and urine.

Invention content:

The purpose of the present invention is to provide a fast and efficient iodide ion determination method; especially to provide a new application of nanomaterials as a colorimetric probe in the determination of iodide ions.

One of purpose of the present invention can be realized by following technical measures:

a, in the presence of modifiers, the solution of soluble salts (silver nitrate, chloroauric acid) is reduced by phenolic compounds as reducing agents to prepare functional silver/gold nanomaterials;

b. Take a certain volume of metal nanomaterials and add a certain volume of buffer solution with a certain pH, a certain concentration of iodide ion standard solution to be measured, and then add a certain concentration of reagents that can make the metal nanomaterials aggregate, and develop color at room temperature for 5 minute.

The purpose of the present invention can also be achieved through the following technical measures:

The modifying agent of the metal nanomaterial is selected from sodium lauryl sulfate, sodium polyphosphate, cetyltrimethylammonium bromide, PDDA polymer, PSS polymer, trisodium citrate; used The phenolic reducing agent is phenol, catechol, dopamine, hydroquinone, gallic acid; the pH range of the buffer solution with a certain pH is 2.0-9.0; the buffer solution used for measuring is acetic acid buffer solution, lemon Acid buffer solution, carbonic acid buffer solution, phosphate buffer solution, Tris buffer solution; the reagents that can make metal nanomaterials gather are hydrogen peroxide, potassium permanganate, potassium dichromate, sodium hypochlorite, ammonium peroxodisulfate, used The concentration of the reagent capable of aggregating metal nanomaterials is 2×10 ^-4 -5×10 ^-2 mol/L.

The "anti-aggregation" nanometer probe involved in the present invention can effectively avoid the interference of metal nanomaterial aggregation caused by other factors in the solution, and the selectivity is greatly improved. The determination time of the method only needs 5 minutes, and the reagents used are simple, cheap and low in cost.

Description of drawings:

Figure 1 is the color change of AgNPs modified by sodium polyphosphate prepared by the invention after adding different concentrations of iodide ion and hydrogen peroxide.

Fig. 2 is the absorption spectrum change of trisodium citrate modified AgNPs prepared by the invention after adding different concentrations of iodide ions and hydrogen peroxide.

Fig. 3 is a graph showing the relationship between the absorbance of the PSS-modified AgNPs prepared by the invention and the iodide ion concentration.

Fig. 4 is the absorption spectrum response diagram of AgNPs modified by trisodium citrate prepared by the invention to other anions.

Detailed ways:

Implementation example 1:

a. Add 5mL of 0.01M sodium polyphosphate in 50mL of silver nitrate solution with 0.1mM as a surface modifier, add 50mL of catechol solution of 0.2mM into the above mixed solution, and reflux for 1h. Sodium polyphosphate modified water-soluble silver nanomaterials;

b. Take 2mL of nano-silver and add 0.1mL, 0.1M (pH 2.2) acetic acid buffer solution, a certain concentration of iodide ion standard solution to be tested, and then add 10μL of 30% hydrogen peroxide aqueous solution, and develop a color reaction for 5 minutes.

Implementation example 2:

a. Add 1mL of 0.01M trisodium citrate in 25mL of silver nitrate solution with 0.1mM as a surface modifier, add 10mL of 0.2mM dopamine hydrochloride into the above mixture, and react at room temperature for 8h to obtain citric acid Trisodium-modified water-soluble silver nanomaterials;

b. Take 2mL of nano-silver and add 0.1mL of 0.1M (pH 4.0) acetic acid buffer solution, a certain concentration of iodide ion standard solution to be tested, and then add 1mL of 0.2mM potassium permanganate solution for color reaction for 5 minutes.

Implementation example 3:

a. Add 5mL of 0.01M sodium lauryl sulfate in 50mL of 0.1mM chloroauric acid solution as a surface modifier, add 20mL of 0.2mM phenol solution into the above mixture, and add 0.1M of hydrogen Sodium oxide solution adjusts the pH of the mixed solution to 8.0, and reacts at room temperature for 24 hours to obtain a water-soluble gold nanomaterial modified with sodium dodecyl sulfate;

b. Take 2mL of nano-gold and add 0.1mL, 0.1M (pH 9.0) citric acid buffer solution, a certain concentration of iodide ion standard solution to be tested, and then add 1mL of 0.2mM hydrogen peroxide solution, and react for 5 minutes for color development .

Claims (4)

1. the fast, efficient detection method of iodide ion, it is characterized in that: a. Under the condition of being selected from sodium lauryl sulfate, sodium polyphosphate, cetyltrimethylammonium bromide, PDDA polymer, and PSS polymer as a modifying agent, by taking from phenol , one of catechol, dopamine, and gallic acid is used as a reducing agent to reduce the solution of silver nitrate or chloroauric (III) acid to prepare functional silver/gold nanomaterials; B, get a certain volume of the metal nanomaterial prepared above and add a certain volume of buffer solution with a certain pH, a certain concentration of iodide ion standard solution to be measured, and then add a certain concentration of hydrogen peroxide, potassium permanganate, One of potassium dichromate, sodium hypochlorite, and ammonium peroxodisulfate is used as a reagent for aggregating the nanomaterials, and the color is developed for 5 minutes at room temperature. 2. The fast and efficient detection method of iodide ion according to claim 1, characterized in that the pH range of the buffer solution with a certain pH is 2.0-9.0. 3. the fast, efficient detection method of iodide ion according to claim 1, it is characterized in that described buffer solution with certain pH is acetate buffer solution, citric acid buffer solution, carbonic acid buffer solution, phosphoric acid buffer solution, Tris buffer solution. 4. the fast, efficient detection method of iodide ion according to claim 1 is characterized in that described adding certain concentration is taken from hydrogen peroxide, potassium permanganate, potassium dichromate, sodium hypochlorite, ammonium peroxodisulfate The concentration of one of them as a reagent for aggregating nanomaterials is 2×10 ^-4 -5×10 ^-2 mol/L.