CN101710076B

CN101710076B - Lead ion colorimetric detection probes and application method thereof

Info

Publication number: CN101710076B
Application number: CN2009102181316A
Authority: CN
Inventors: 关威; 苏忠民; 代起君; 柴芳; 王春刚; 李鹿; 赵亮; 高洪泽
Original assignee: Northeast Normal University
Current assignee: Northeast Normal University
Priority date: 2009-12-29
Filing date: 2009-12-29
Publication date: 2012-07-04
Anticipated expiration: 2029-12-29
Also published as: CN101710076A

Abstract

The invention belongs to the technical field of detection and particularly relates to lead ion colorimetric detection probes and an application method thereof. In the method, glutathione modified gold nanoparticles are used as colorimetric probes, glutathione combines with gold nanoparticles by utilizing sulfydryl groups of the glutathione for coordination to form a stable structure of which the surface contains two free carboxyl radicals. In the process of detection, the carboxyl radicals can coordinate with heavy metal ions; and by utilizing the property of surface plasma resonance of the gold nanoparticles, the existence of the heavy metal ion Pb2+ in aqueous solution can be indicated by the color change of the solution. The lead ion colorimetric detection probes have the advantages that: the sensitivity and selectivity are high; in-situ quick detection can be realized without large-size instruments; the detection results are visual and can be observed by naked eyes; the operation is simple and the cost is low; and the used solvents and the operation processes have no toxic or side effects.

Description

A kind of lead ion colorimetric detection probes and application process thereof

Technical field

The invention belongs to the detection technique field, be specifically related to a kind of lead ion colorimetric detection probes and application process thereof.

Background technology

Heavy metal ion (mercury Hg ²⁺Plumbous Pb ²⁺Cadmium Cd ²⁺Copper Cu ²⁺), particularly mercury, cadmium, lead, copper etc. have significant bio-toxicity.They can not be degraded by microorganisms in water body, and can only take place that various forms transform each other and dispersion, enrichment process (i.e. migration).Heavy metal-pollutedly have a finger in every pie the environmental pollution that causes by heavy metal or its compound.Mainly by due to the human factors such as mining, toxic emission, sewage irrigation and use heavy metal goods.Its extent of injury depends on concentration and the chemical form that heavy metal exists in environment, food and biosome.

Heavy metal generally extensively is present in occurring in nature with natural concentration; But it is because human increasing to exploitation, smelting, processing and the commercial manufacturing activities of heavy metal; Cause many heavy metals to get in atmosphere, water, the soil, cause the serious environmental pollution like lead, mercury, cadmium, cobalt etc.Heavy metal so that various chemical states or chemical form exist will retain, accumulates and move after getting into the environment or the ecosystem, works the mischief.The pollution of heavy metal causes very big harm sometimes, and wherein, plumbous and its compound is respectively organized all toxic to human body; Saturnine harm shows that mainly saturnism can cause renal function malfunctioning in the injury to lifelong property such as nervous system, hematological system, cardiovascular system, skeletal system, suppresses brain development; Particularly, can cause multiple neurotoxic effect, because lead is nondegradable for children; Its persistence in environment exists; And can be created in the toxic action of plant and animal, this shows that saturnine harm is serious, therefore prevention and testing just become extremely important.The symptom after the saturnism is often very hidden is difficult to come to light, and these are all relevant with ecological deterioration.The lead of motor vehicle exhaust emission gets in the environment through processes such as atmospheric diffusion, causes the plumbous concentration in the present face of land to be significantly increased, causes uptake plumbous in the human body in modern age to increase about 100 times than the primitive man, has damaged health.Therefore, the real-time detection that realizes the heavy metal ion in environmental area or the biosome with and the original position fast detecting have crucial meaning.

Measuring the normal method that adopts of trace heavy metal ion concentration has: atomic absorption spectrography (AAS), belong to conventional elemental microanalysis method, but low to the mensuration sensitivity of trace element, complicated operation.The Zeeman effect GFAAS is a kind of method accurately and reliably, but same complicated operation, and costly, be difficult to large-scale application.Have in addition and utilize complexing agent and form the method that colored complex carries out colorimetric estimation with ion, but its sensitivity is low, poor reproducibility generally seldom adopts now.The fluorescent molecular probe technology is applied to the detection of transition metal and heavy metal ion, can realize in situ detection, but fluorescence probe has quite good detecting effectiveness usually in organic solvent, and certain limitation is arranged in the WS.In recent years, use aptamer (adaptive son) or DNA enzyme etc. to come to prepare probe, be used to detect Pb with gold nano grain as functionalized reagent ²⁺Etc. heavy metal ion [Wang Z D, Lee J H, Lu Y, Adv.Mater.2008,20,3263-3267; Liu J W, Lu Y, 2004, J.Am.Chem.Soc.2004,126,12298-12305; Liu, J W, Lu Y, 2004, Anal.Chem.76,1627-1632; Liu J W, Lu Y, J.Am.Chem.Soc.2005,127,12677-12683; Wei H, Li B L, Dong S J, Wang E K, 2008,19,095501.], can reach sensitivity preferably and selectivity, but, can not become the selection of widespread usage because DNA and enzyme cost are higher.

To above problem, we have studied a kind of nanogold particle colloidal sol of functionalization that utilizes and have used the method that detects heavy metal ion as the colorimetric device.It is a kind of simple to operate, quick that the present invention provides, and can not realize the method to the heavy metal ion fast detecting by instrument (bore hole observation colorimetric).

Summary of the invention

The purpose of this invention is to provide a kind of colorimetric detection probes that can in the WS, detect the heavy metal lead ion.

Another object of the present invention provides the application process of a kind of lead ion colorimetric detection probes in heavy metal ion detects.

Lead ion colorimetric detection probes of the present invention is the gold nano grain of glutathione (GSH) functionalization.Glutathione is owing to the mercapto groups in its structure is prone to combine with gold nano grain; Therefore modify gold nano grain with it; Obtain the gold nano grain GSH-GNPs of glutathione functionalization; It contains the structure of two free carboxyl groups, and glutathione functionalization gold nano grain can become the colorimetric probe that detects heavy metal ion.In testing process, two free carboxyl groups can with the heavy metal ion coordination, utilize the character of the surface plasma resonance of gold nano grain, through colorimetric detection method, can detect the trace heavy metals ion Pb that contains in the WS ²⁺

One, the synthetic method of the nanogold particle (GSH-GNPs) of colorimetric probe glutathione functionalization:

Under the room temperature, be to be made into the WS at 3～6: 1 by the amount of substance ratio of two kinds of reactants of GSH and gold chloride, two kinds of solution mix under magnetic agitation; Solution becomes white emulsion fluid by faint yellow; The pH value of regulating mixed solution with the NaOH solution of 0.5～1M/L is in 6～8 scopes, and solution becomes clarification gradually in this process, the sodium borohydride frozen water solution reduction of newly preparing with 1～2mg/mL then; Continue to keep stirring 10～24 hours; The centrifugal unreacted matters of removing is distributed to goldc grains in the water more again, just obtains the nanogold particle (GSH-GNPs) of solution colour for red glutathione functionalization; The test ultraviolet-visible spectrum has characteristic absorption at the 520nm place, and the nanogold particle of glutathione functionalization is lead ion colorimetric detection probes.

Two, detect lead ion (Pb ²⁺)

1, detection sensitivity

Use GSH-GNPs to detect Pb as colorimetric detection probes ²⁺The time, have higher sensitivity.With adding in the sample to be measured of equivalent in 2～5 times the colorimetric probe solution of dilution, add 10% the 1～2MNaCl solution that accounts for overall solution volume then, if there is not Pb in the testing sample ²⁺, then the red color of colorimetric probe solution can remain unchanged, as the Pb that contains greater than 5 μ M ²⁺, the color of solution can become purple or pewter by redness.(decide) after 10～30 minutes according to the concentration of lead ion in the solution; Through the uv-visible absorption spectra of test solution, can carry out colorimetric detection, there is lead ion; The uv-visible absorption spectra generation red shift of goldc grains; And absorption spectrum and plumbum ion concentration have good linear relationship, and the gold nano grain of glutathione functionalization can be used as the existence of the probe fast detecting lead ion in the WS that detects lead ion, and detectability can reach 100nM.

2, selectivity

Use the nanogold particle of glutathione functionalization to detect Pb as colorimetric detection probes ²⁺The time, have high selectivity.With Hg ²⁺, Mg ²⁺, Zn ²⁺, Ni ²⁺, Cu ²⁺, Co ²⁺, Ca ²⁺, Mn ²⁺, Fe ²⁺, Mg ²⁺, Cd ²⁺And Ba ²⁺When detecting comparison, the colorimetric probe is to Pb ²⁺Have extraordinary selectivity, under the same terms, detect Pb ²⁺Concentration ratio Hg ²⁺, Mg ²⁺, Zn ²⁺, Ni ²⁺, Cu ²⁺, Co ²⁺, Ca ²⁺, Mn ²⁺, Fe ²⁺, Mg ²⁺, Cd ²⁺And Ba ²⁺Low 100～1000 times of the concentration of ion explains to have high selectivity.

The present invention has following advantage:

1, detector probe provided by the invention is highly sensitive, selectivity good, and detectability is low.

2,, can discern testing result through colorimetric (bore hole is observed or ultraviolet spectrum) not by instrument.

3, the present invention is prone to preparation and preserves; Under 4 ℃ of conditions, can preserve 6～12 months.

4, agents useful for same of the present invention and operating process all have no side effect.

5, the inventive method is simple, quick, easy to operate, does not need large-scale instrument, can carry out on-the-spot original position fast detecting.

Description of drawings

The uv-visible absorption spectra of accompanying drawing 1, colorimetric probe in detecting lead ion and than colour contrast photo:

Wherein, the absorption spectrum of a colorimetric probe and corresponding solution photo; B detects absorption spectrum and corresponding solution photo behind the lead ion for the colorimetric probe solution.

The linear relationship of the absorption ratio of the absorption spectrum behind the lead ion of accompanying drawing 2, colorimetric probe in detecting variable concentrations and lead ion initial concentration (1-50 μ M).

Embodiment

Embodiment 1:

Under the room temperature; Is to be made into aqueous solution at 6: 1 to stir with the WS of gold chloride and glutathione by the amount of substance ratio, and with the sodium hydroxide solution of 1M the pH value of mixed solution is adjusted to 7.0, in mixed solution, adds sodium borohydride frozen water solution (2mg/1mL) and the vigorous stirring of newly preparing then; Mixed solution sustained response 12 hours under stirring condition; Centrifugal removing behind the unreacting substance disperseed again, just obtained the gold nano grain of glutathione functionalization, i.e. the colorimetric probe; Survey its uv-visible absorption spectra, characteristic absorption is arranged at the 520nm place.

Embodiment 2:

When using colorimetric probe in detecting lead ion; With 4 times of the colorimetric probe dilution that makes; The colorimetric probe solution of getting after 100 μ l dilute adds in the biological tissue to be measured or environmental wastewater sample of equivalent, adds 20 μ l then, 1M NaCl solution; Judge whether the existence of lead ion through the variation of observing solution colour, solution becomes purple or pewter by the redness of gold grain when having lead ion; Or the uv-visible absorption spectra of test solution, there is lead ion, the ultraviolet-visible characteristic absorption spectrum generation red shift of solution, and the concentration of absorption spectrum and lead ion has good linear relationship, judges with this whether testing sample has existing of lead ion.

Claims

1. a lead ion colorimetric detection probes is characterized by the gold nano grain that the colorimetric probe is the glutathione functionalization, and solution is peony; The test ultraviolet-visible spectrum; At the 520nm place characteristic absorption is arranged, run into lead ion absorption spectrum generation red shift, solution colour becomes purple or pewter; This probe is made by following method: under the room temperature; Is to be made into aqueous solution at 6: 1 to stir with the WS of gold chloride and glutathione by the amount of substance ratio, and with the sodium hydroxide solution of 1M the pH value of mixed solution is adjusted to 7.0, in mixed solution, adds sodium borohydride frozen water solution 2mg/1mL and the vigorous stirring of newly preparing then; Mixed solution sustained response 12 hours under stirring condition is centrifugally disperseed after removing unreacting substance again.

2. the application process of a lead ion colorimetric detection probes that makes by the described method of claim 1; Its testing process is: when the gold nano grain of use glutathione functionalization detects Pb2+ as detector probe; With adding in the colorimetric probe solution of 2～5 times of dilutions in the detection of biological tissue to be measured and environmental wastewater sample of equivalent; Add 10% the 1～2M NaCl solution account for overall solution volume then and change the ionic strength of solution, observe the change color of mixed solution, or test its uv-visible absorption spectra; Can carry out colorimetric detection; When having lead ion, the mixed solution color becomes purple or bluish grey by the redness of gold nano grain, or the ultraviolet-visible characteristic absorption spectrum generation red shift of solution; And absorption spectrum and ion concentration have good linear relationship, through the existence of displacement decidable lead ion and the contained concentration of color and absorption spectrum.