CN111624296B - High-efficiency thin-layer chromatography separation method based on metal organic framework material composite photonic crystal thin layer - Google Patents
High-efficiency thin-layer chromatography separation method based on metal organic framework material composite photonic crystal thin layer Download PDFInfo
- Publication number
- CN111624296B CN111624296B CN202010503057.9A CN202010503057A CN111624296B CN 111624296 B CN111624296 B CN 111624296B CN 202010503057 A CN202010503057 A CN 202010503057A CN 111624296 B CN111624296 B CN 111624296B
- Authority
- CN
- China
- Prior art keywords
- thin layer
- photonic crystal
- mof
- sio
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/90—Plate chromatography, e.g. thin layer or paper chromatography
- G01N30/92—Construction of the plate
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/90—Plate chromatography, e.g. thin layer or paper chromatography
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/90—Plate chromatography, e.g. thin layer or paper chromatography
- G01N30/92—Construction of the plate
- G01N30/93—Application of the sorbent layer
Abstract
The invention discloses a metal organic framework material composite photonic crystal (MOF-PC) thin layer and a high-efficiency thin layer chromatography separation technology based on an MOF-PC thin layer plate. As a chromatographic stationary phase, the MOF-PC thin layer has a high specific surface area and a specific microporous structure, so that a stronger adsorption and desorption effect and selectivity are shown in separation, the inherent defect of poor separation effect caused by low number of thin layer chromatographic plates is effectively overcome, and efficient separation of mixed substances is ensured. The MOF-PC thin layer also has a structural color and a reflection signal which are specific to the photonic crystal, so that the specific position of the sample can be directly determined by using the structural color difference between a sample point and the thin layer plate and the change of the reflection signal, and the chromatographic parameters such as a specific displacement value, a selection factor, a separation degree and the like can be obtained. Compared with the prior art, the technology provided by the invention has a remarkably improved separation effect, and can be used for separating substances with similar structures, which cannot be separated by the traditional thin-layer chromatography. In addition, the technology directly identifies sample points by means of structural colors, does not need additional operations such as ultraviolet irradiation, laminate dyeing and the like, and provides a new green, convenient and safe way for sample detection.
Description
Technical Field
The invention belongs to the field of photonic crystal material application and the technical field of thin-layer chromatography separation, and particularly relates to a high-efficiency thin-layer chromatography technology taking a metal organic framework material composite photonic crystal thin-layer plate as a stationary phase.
Background
The thin-layer chromatography is a chromatography separation technology which takes a granular thin layer coated on a glass plate as a stationary phase, takes a specific solvent as a mobile phase and separates and identifies a mixed sample by utilizing the differential adsorption and desorption action between a chemical substance and the stationary phase. Since the 20 th century and the 50 th century, the technology is widely applied to the relevant professional fields of food safety detection, drug identification, metabolite analysis, organic synthesis, chemical product identification, drug analysis, pesticide residue detection and the like due to the advantages of convenient operation, simple equipment requirement and the like. In practical application, the thin-layer chromatography separation comprises the operations of plate preparation, sample application, development, color development and the like; the chemical composition of the sample point can be determined qualitatively by comparing the sample point with the reference object shift value after separation, and the content of each component in the mixture can be quantitatively determined by combining ultraviolet visible scanning and fluorescence scanning, so that the method has important practical value.
Although thin-layer chromatography has various advantages of rapidness, simplicity, convenience, high efficiency, economy and the like, the technology has the disadvantages of low separation efficiency and various and complicated sample detection conditions due to inherent characteristics, and the application of the thin-layer chromatography in various occasions is limited. It is well known that the migration distance of analytes in a stationary phase in thin layer chromatography separation is typically 2 to 4cm, much lower than the migration distance of 10 to 20m in a gas, liquid chromatography column; this results in the theoretical number of plates for thin layer chromatography separation being necessarily orders of magnitude lower than that of the latter, which results in very limited times of adsorption and desorption between the substance and the thin layer, resulting in low separation efficiency of thin layer chromatography and failure to separate structurally similar chemical substances. In order to improve the separation efficiency of the thin-layer chromatography, researchers have developed various high-efficiency thin-layer chromatography technologies such as rod-like thin-layer chromatography, pressurized thin-layer chromatography, centrifugal thin-layer chromatography, micelle thin-layer chromatography, inclusion thin-layer chromatography, two-dimensional thin-layer chromatography and the like. Although these techniques have their own applications, it has been discovered that the use of modified silica gel particles having a smaller and more uniform particle size, and the increased selectivity of the stationary phase is an effective way to increase the efficiency of thin layer chromatographic separations.
On the other hand, the conditions for detecting samples separated by thin layer chromatography are various and complicated. For colored substances, the colored substances can be directly identified on a white silica gel plate after separation; for colorless but fluorescent substances, they can be identified after separation under the irradiation of ultraviolet lamp. The most widely used at present is a fluorescent silica gel plate which is mainly used for separating colorless substances with ultraviolet visible absorption and utilizes fluorescence quenching to identify sample points under the irradiation of an ultraviolet lamp. For the identification and detection of many colorless, ultraviolet-visible absorption-free and fluorescence-free characteristic substances, the substances must be dyed by sulfuric acid and potassium permanganate, so that the operation steps of thin-layer chromatography separation are increased, and the risk of using dangerous chemicals by operators is increased. Currently, in thin layer chromatography sample detection, there is no simple and uniform solution to the above detection problem except for the combination of various spectrometers.
Colloidal photonic crystals may be ideal thin-layer chromatography stationary phase materials for both efficient separation and visual detection. This is because the size of the nano colloidal particles in the colloidal crystal is about 0.2 μm, which is much smaller than commercial silica gel particles, resulting in higher separation efficiency; meanwhile, the colloidal crystal has structural color, and sample points can be visually identified without ultraviolet irradiation and dyeing. The applicant of the present invention has published about "based on mesoporous SiO" in 20172The academic paper of thin layer chromatography separation of photonic crystals, however, the separation efficiency of the thin layer chromatography stationary phase in the above work is improved to a limited extent compared with commercial silica gel plates, and the structurally similar chemical substances proposed in the present invention, such as cresol isomers, cannot be separated. In addition to the above work, no report on the separation technique of photonic crystal thin layer chromatography has been found on the basis of a great deal of research by the applicant. Therefore, the development of a new colloidal photonic crystal thin-layer chromatography technology with stronger separation capability and structural color detection has important significance and value.
Disclosure of Invention
The invention provides a high-efficiency thin-layer chromatography technology based on a metal organic framework Material (MOF) composite photonic crystal (MOF-PC) thin layer (thin layer plate) aiming at the defects of the existing thin-layer chromatography technology. As the chromatographic stationary phase, the MOF-PC thin layer has high specific surface area and a unique pore channel structure, so that stronger adsorption and desorption effects and selectivity are shown in the separation, the inherent defect of poor separation effect caused by low number of thin layer chromatographic plates is effectively overcome, the efficient separation of mixed substances is ensured, and the separation efficiency is greatly improved; the MOF-PC thin layer also has a structural color and a reflection signal which are specific to the photonic crystal, so that the specific position of the sample can be directly determined by using the structural color difference between a sample point and the thin layer plate and the change of the reflection signal, and the chromatographic parameters such as a specific displacement value, a selection factor, a separation degree and the like can be obtained. Meanwhile, the visual detection of substances is realized by utilizing the structural color of the photonic crystal, so that the detection process is simplified and the operation safety is improved. Compared with the prior art, the technology provided by the invention has a remarkably improved separation effect, and can be used for separating substances with similar structures, which cannot be separated by the traditional thin-layer chromatography. In addition, the technology directly identifies sample points by means of structural colors, does not need additional operations such as ultraviolet irradiation, laminate dyeing and the like, and provides a new green, convenient and safe way for sample detection.
The invention provides a preparation method of an MOF-PC thin layer, which specifically comprises the following steps:
(1) will contain silicon dioxide (SiO)2) Coating the supersaturated solution of colloidal particles on a substrate, and heating to obtain solid SiO2A photonic crystal thin layer.
(2) Recovering the above solid SiO2SiO in photonic crystal thin layer2Surface hydroxyl of colloidal particles, and then performing amino modification and carboxyl modification on the colloidal particles to obtain carboxyl-modified SiO2A photonic crystal thin layer.
(3) SiO modified by carboxyl2Alternately soaking the photonic crystal thin layers in a solution containing metal ions and a solution containing ligands, and growing the layers on the SiO by a layer-by-layer liquid phase growth method2Forming an MOF layer on the surface of the colloidal particles in situ to prepare the metal organic framework material composite photonic crystal (MOF-PC) thin layer.
In the step (1), the SiO-containing compound2The supersaturated solution of colloidal particles is SiO with the volume fraction of 20-40%2Colloidal particles supersaturated with colloidal particles comprising 60-80% by volume of a solventA solution; preferably, it is 35% SiO by volume fraction2A supersaturated solution of colloid particles with 65% by volume of ethylene glycol.
Wherein the SiO2The colloid is monodisperse SiO2And (3) colloid.
Wherein the solvent is an organic solvent and is selected from one or more of ethylene glycol, dimethyl sulfoxide, dimethylformamide, propylene carbonate and the like; preferably, it is ethylene glycol.
In the step (1), the substrate is one or more of a glass substrate, a plastic substrate, a silicon wafer and the like; preferably a glass substrate.
In the step (1), SiO2The thickness of a liquid film formed by coating the supersaturated solution of the colloidal particles on the substrate is 100-300 microns; preferably, the liquid film thickness is 100 microns.
In the step (1), the SiO2The size of the colloidal particles is 150-1000 nm; preferably 200 nm.
In the step (1), the solid SiO2The photonic crystal thin layer is SiO-containing2The supersaturated solution of colloidal particles is coated on a substrate, and after heating to volatilize the solvent, SiO is formed2The colloidal particles are orderly stacked to form a granular film.
The purpose of heating in the step (1) is as follows: and volatilizing the solvent to dry and solidify the film.
In the step (1), the heating temperature is 60-100 ℃; preferably, it is 90 ℃.
In the step (1), the heating time is 10-120 minutes; preferably, it is 30 minutes.
In the step (1), after the heating step, a high-temperature calcination step is further included, and the purpose of performing the high-temperature calcination is as follows: and the mechanical strength of the film is enhanced.
Wherein the temperature of the high-temperature calcination is 450-550 ℃; preferably, it is 500 ℃.
Wherein the high-temperature calcination time is 1-4 hours; preferably, it is 2 hours.
The high-temperature calcination operation step is preferably to mix SiO2Thin layer arrangement of photonic crystalCalcining at high temperature in a muffle furnace.
In the step (2), the SiO is recovered2The operation of the hydroxyl on the surface of the colloidal particle is to mix solid SiO2Soaking the photonic crystal thin layer in a solvent with the volume ratio of 7: 3 concentrated sulfuric acid and 30 percent hydrogen peroxide by mass fraction, so that a large amount of hydroxyl groups are formed on the surface of the colloidal particles.
The soaking time is not less than 2 hours; preferably, it is 12 hours.
The solid SiO2The volume ratio of the photonic crystal thin layer to the mixed solution is 1: (300-2000); preferably, 1: 1000.
the purpose of performing surface carboxyl modification in the step (2) is as follows: the adsorption capacity of the colloidal particles to metal ions is enhanced.
In the step (2), the amino group is modified by: SiO that will restore surface hydroxyl2Soaking the photonic crystal thin layer in ethanol solution containing Aminopropyltriethoxysilane (APTES) or ethanol solution containing Aminopropyltrimethoxysilane (APTMS) for reaction. Taking out, washing with ethanol and drying to obtain SiO with rich amino groups on the surface2A photonic crystal thin layer.
The volume fraction of aminopropyltriethoxysilane APTES or aminopropyltrimethoxysilane APTMS in the ethanol solution is 0.03-0.18%; preferably, the volume fraction is 0.06%.
The reaction temperature is 20-80 ℃; preferably, room temperature.
The reaction time is not less than 4 hours; preferably, it is 12 hours.
The SiO for recovering surface hydroxyl2The volume ratio of the photonic crystal thin layer to the solution is 1: (300-2000); preferably, 1: 1000. the solution refers to an ethanol solution containing Aminopropyltriethoxysilane (APTES) or an ethanol solution containing Aminopropyltrimethoxysilane (APTMS).
In the step (2), the carboxyl is modified into SiO modified by amino2Soaking the photonic crystal thin layer in a dimethylformamide solution of succinic anhydride with the concentration of 0.0025-0.01g/mL for reaction; preferably, the solution concentration is 0.005 g/mL.
Taking out, washing with ethanol and drying to obtain SiO with rich carboxyl on the surface2A photonic crystal thin layer.
The reaction temperature is 20-80 ℃; preferably, room temperature.
The reaction time is 4-24 hours; preferably, it is 12 hours.
The amino-modified SiO2The volume ratio of the photonic crystal thin layer to the solution is 1: (300-2000); preferably, 1: 1000. the solution refers to a dimethylformamide solution containing succinic anhydride.
In the step (3), the metal organic framework material composite photonic crystal (MOF-PC) thin layer is formed by depositing and wrapping various MOF materials on SiO2A composite photonic crystal thin layer is formed on the surface of the colloidal particles; preferably, the MOF materials are HKUST-1, ZIF-8 and MIL-100.
The MOF-PC thin layer prepared by the invention is the MOF-PC thin layer only containing one MOF material.
In the step (3), the metal ion solution is a solution containing metal ions required for generating the metal organic framework material, and is Cu (CH)3COO)2·H2O ethanol solution, Zn (NO)3)2·6H2O methanol solution, FeCl3·6H2Ethanol O solution, etc.; similarly, the ligand solution is a solution containing the ligand needed for generating the metal organic framework material, and is a trimesic acid ethanol solution, a 2-methylimidazole methanol solution and the like.
Specifically, Cu (CH) is used for preparing HKUST-1 composite photonic crystal thin layer3COO)2·H2O ethanol solution (50mM) and trimesic acid ethanol solution (5 mM); zn (NO) is used for preparing ZIF-8 composite photonic crystal thin layer3)2·6H2O methanol solution (2mM) and 2-methylimidazol methanol solution (5 mM); FeCl is used for preparing the MIL-100 composite photonic crystal thin layer3·6H2Oethanol solution (20mM) and trimesic acid ethanol solution (20 mM).
In the step (3), the layer-by-layer liquid phase growth method is a chemical method for preparing a composite structure by in-situ reaction, namely SiO2The photonic crystal thin layer is firstly soaked inAnd soaking the metal ion solution in a ligand solution after being taken out to react to form a first MOF layer, soaking the thin layers in the metal ion solution and the ligand solution again to form a second MOF layer, and processing the second MOF layer in a liquid phase environment by a method to finally form the MOF composite photonic crystal thin layer.
Each layer of MOF is grown to SiO2The photonic crystal is soaked in the metal ion and ligand solution for 10 to 60 minutes in sequence; preferably, it is 30 minutes.
The reaction temperature of the MOF growth is 20-100 ℃; preferably, it is 40 ℃.
SiO in the MOF growth process2The volume ratio of the photonic crystal thin layer to the metal ion or ligand solution is 1: (1000-; preferably 1: 2000.
the MOF growth is 1-10 growth cycles; preferably, there are 7 growth cycles.
The invention also provides a metal organic framework material composite photonic crystal (MOF-PC) thin layer prepared by the method.
The invention also provides application of the metal organic framework material composite photonic crystal (MOF-PC) thin layer in high-efficiency thin layer chromatography separation.
The invention also provides a MOF-PC-based thin-layer chromatography separation method, which specifically comprises the following steps:
(1) the solution containing the analyte is spotted onto the MOF-PC thin layer plate prepared as described above, forming sample spots having a different structural color compared to the MOF-PC thin layer.
(2) And transferring the MOF-PC thin-layer plate into an unfolding cylinder, and waiting for the organic solvent to unfold the sample until the front edge of the unfolding agent reaches a preset position.
(3) The MOF-PC thin layer panels were taken out of the expansion cylinder, digital photographs were taken and spatially resolved reflectance spectra were collected. Determining the chromatographic parameters of each component in an analyte by using the structural color difference and the reflection spectrum signal difference of the sample point and the MOF-PC thin-layer plate, and determining the attribution of the separated sample point by referring to the interaction strength of each component and the stationary phase.
The MOF-PC thin layers of the invention can also be called MOF-PC thin layer plates, and the MOF-PC thin layers are taken as a thin layer chromatography stationary phase in the step (1), so that the MOF-PC thin layer plates are called MOF-PC thin layer plates.
Step (1) the solution containing the analyte is spotted onto the MOF-PC thin layer plate, preferably using a capillary.
In the step (1), the solution containing the analyte refers to a methanol solution containing 30-60% by volume of o-cresol and m-cresol, an ethanol solution containing 30-60% by volume of o-cresol and m-cresol, an aqueous solution containing 30-60% by volume of o-cresol and m-cresol, and the like; preferably, the methanol solution contains 50 percent of o-cresol and m-cresol by volume fraction.
In the step (2), the organic solvent is petroleum ether, benzene, tetrahydrofuran, ethyl acetate, methanol and other common thin-layer chromatography developing agents; preferably, the solvent is a mixed solvent of petroleum ether and ethyl acetate.
In the step (3), the chromatographic parameters comprise a specific displacement value, a plate number, a selectivity factor, a separation degree and the like.
In the step (3), the collection of the spatial resolution reflection spectrum is realized by fixing a spectrometer fiber probe above a thin-layer chromatographic plate, and pulling the thin-layer plate along the unfolding direction at a constant speed of 1-4cm/min, so that the spectrometer can continuously record the reflection spectrum change along the unfolding direction; preferably, the rate of pulling the lamina is 2 cm/min.
The spectrometer records the reflection spectrum and records a reflection peak signal every 0.5-2 seconds; preferably every 1 second.
In the step (3), the spatially resolved reflectance spectrum refers to a three-dimensional reflectance spectrum in which the expansion distance is represented by an x-axis, the reflection wavelength is represented by a y-axis, and the reflection intensity is represented by color. And accurately determining the specific displacement value of the substance through the convex position of the reflection band in the spectrogram.
In one embodiment, the MOF-PC thin layer and the MOF-PC-based thin layer chromatographic separation method specifically comprise the following steps:
(1) will contain silicon dioxide (SiO)2) The supersaturated solution of colloidal particles is coated on a glass substrate to form a layer of uniform SiO2A liquid photonic crystal layer. Heating ofDrying and solidifying the liquid film by volatilizing the solvent to form solid SiO2A photonic crystal thin layer. The thin layer is calcined at a high temperature to further enhance the mechanical strength of the thin layer.
(2) Recovering SiO in the photonic crystal thin layer by soaking treatment2Surface hydroxyls of the micelle. Sequentially carrying out amino modification and carboxyl modification on the surface of the colloidal particles through room-temperature chemical reaction to finally obtain the SiO with rich carboxyl on the surface2A photonic crystal thin layer.
(3) Enriching the surface with carboxyl SiO2Alternately soaking the photonic crystal thin layers in a solution containing metal ions and a ligand solution, and growing the photonic crystal thin layers on the SiO by a layer-by-layer liquid phase growth method2Forming an MOF layer on the surface of the colloidal particles in situ to prepare a metal organic framework material composite photonic crystal (MOF-PC) thin layer with structural color.
(4) And (3) spotting the solution containing the analyte on the MOF-PC thin-layer plate prepared in the step (3) by using a capillary to form a sample spot with a different structural color compared with the MOF-PC thin layer.
(5) And when the structural color of the sample point is not changed, transferring the MOF-PC thin-layer plate into a spreading cylinder filled with a specific organic solvent, sealing the container for several minutes, and waiting for the organic solvent to spread the sample until the front edge of the spreading agent reaches a preset position.
(6) And opening the expansion cylinder, taking out the MOF-PC thin-layer plate, rapidly recording image information by using a digital camera, and simultaneously collecting a spatially resolved reflection spectrum along the expansion direction by using a spectrometer. Determining chromatographic parameters such as a specific shift value (Rf) of each component in an analyte by using the structural color difference and the reflection spectrum signal difference between a sample point and an MOF-PC thin-layer plate; and finally determining the attribution of the sample points by referring to the interaction strength of each component and the stationary phase.
Compared with the prior art, the invention has the beneficial effects that: the invention provides a high-efficiency thin-layer chromatography separation technology based on a metal organic framework material composite photonic crystal thin-layer plate, which can synchronously realize high-efficiency separation of substances and structural color detection; the technology is proposed for the first time, and no report is found so far. Compared with the traditional silica gel thin-layer chromatography, the new technology adopts the MOF photonic crystal thin layer with high specific surface area, specific microporous structure and uniform structural color as the stationary phase, strengthens the adsorption and desorption process of the substances, improves the selectivity to the analyte, obviously improves the separation effect, and successfully separates the substances with similar structures which can not be separated by the traditional thin-layer chromatography. Meanwhile, when a sample point is detected after separation by the novel chromatographic technology, ultraviolet irradiation development and sulfuric acid and iodine dyeing development are not needed, and the sample point can be accurately identified directly through the structural color difference between the sample and the MOF photonic crystal chromatographic plate, so that a green, convenient and safe novel way is provided for sample detection. Therefore, the technology has wide application prospect in future basic scientific research and fine chemical production.
Drawings
FIG. 1 is a schematic representation of MOF-PC based high performance thin layer chromatography for cresol isomer separation.
In FIG. 2, the graphs a, d, g and j are respectively HKUST-1 composite SiO2A physical photograph, a scanning electron microscope image, a reflection spectrum and an X-ray diffraction spectrum of the photonic crystal thin layer;
b, e, h and k are respectively ZIF-8 composite SiO2A physical photograph, a scanning electron microscope image, a reflection spectrum and an X-ray diffraction spectrum of the photonic crystal thin layer;
in the diagrams c, f, i and l are respectively MIL-100(Fe) composite SiO2A physical photograph, a scanning electron microscope image, a reflection spectrum and an X-ray diffraction spectrum of the photonic crystal thin layer.
FIG. 3 is a typical spatially resolved reflectance spectrum of a non-sample MOF-PC sheet (a), after spotting (b).
FIG. 4 shows the migration of o-cresol (a-c) and m-cresol (d-f) on HKUST-1, ZIF-8 and MIL-100 composite photonic crystal thin-layer plates.
FIG. 5 shows the separation (a) and identification (b) of a mixture of o-cresol and m-cresol on MIL-100 composite photonic crystal thin layer plates.
FIG. 6 is a separation of o-cresol, m-cresol, and a mixture of o-cresol and m-cresol on commercial silica gel thin layer plates.
FIG. 7 shows the theoretical plate number, selectivity factor and actual separation degree of cresol isomers exhibited by the stationary phase in different chromatographic separations, and FIG. (a) shows the theoretical plate number of the sample; panel (b) shows the selectivity factor and the actual degree of separation for immobilized relative analytes.
Detailed Description
The present invention will be described in further detail with reference to the following specific examples and the accompanying drawings. The procedures, conditions, experimental methods and the like for carrying out the present invention are general knowledge and common general knowledge in the art except for the contents specifically mentioned below, and the present invention is not particularly limited.
Example 1 preparation of SiO2Photonic crystal thin layer
By using
Method for preparing monodisperse SiO with average grain diameter of 200nm2Colloidal particles. Taking 80 mu L of SiO2The colloidal particles were dispersed in 1mL of ethanol and 120. mu.L of ethylene glycol was added and mixed by sonication to form a homogeneous, transparent solution. And standing the mixed solution in a 90 ℃ oven for 2 hours to volatilize and remove ethanol in the solution, and finally obtaining 200 mu L of colloid supersaturated solution with the volume fraction of colloidal particles of 40%. And (3) dropwise adding 30 mu L of the precursor solution on a hydrophilic glass substrate treated by the piranha solution, and uniformly spreading the precursor solution into a liquid film with the thickness of about 100 mu m by a coating method. Standing at room temperature for 15 min, separating out a large amount of colloid crystal grains to form liquid colloid crystal, transferring into a 90 deg.C oven, heating for 2 hr, and volatilizing ethylene glycol to obtain SiO with uniform structural color2A photonic crystal thin layer. Then the solid SiO2The photonic crystal thin layer is calcined for 2 hours at 550 ℃, and the mechanical strength and the adhesion force to the substrate of the thin layer are further enhanced.
Example 2 preparation of a Metal organic framework Material composite Photonic Crystal (MOF-PC) thin layer
First, calcined SiO of inventive example 12And soaking the photonic crystal thin layer in the piranha solution for 12 hours to recover the surface hydroxyl. Followed by hydroxylation of SiO2Soaking the photonic crystal thin layer in 0.06% Aminopropyltriethoxysilane (APTES) ethanol solution, reacting at room temperature for 12 hr, and collectingAnd washing and drying the crystal by using ethanol to obtain the surface amino modified photonic crystal thin layer. And finally, soaking the amino modified photonic crystal thin layer in a succinic anhydride dimethylformamide solution with the concentration of 0.005g/mL, reacting at room temperature for 12 hours, taking out, washing with ethanol, and drying to obtain the photonic crystal thin layer with the surface rich in carboxyl.
And alternately soaking the carboxyl modified photonic crystal thin layer in a metal ion and ligand solution to induce the MOF material to grow in situ on the surface of the colloidal particles, and preparing to obtain the metal organic framework material composite photonic crystal (MOF-PC) thin layer. Taking the preparation of a MIL-100-PC thin layer as an example, a carboxyl-modified photonic crystal thin layer was immersed in FeCl at a concentration of 20mM3·6H2And O ethanol solution, reacting for 1 hour at 40 ℃, taking out, washing with ethanol and drying. Then, the mixture was soaked in 20mM ethanol trimesic acid, reacted at 40 ℃ for 1 hour, taken out, washed with ethanol and dried. Through the surface adsorption and the in-situ reaction, a very thin layer of MIL-100 is generated on the surface of the colloidal particles. Repeating the soaking operation for a plurality of times to grow a layer of MOF structure on the surface of the colloidal particles, and finally obtaining the photonic crystal thin layer with controllable thickness and uniformly coated MIL-100. Cu (CH) with a concentration of 50mM is applied using the same layer-by-layer growth technique3COO)2·H2The HKUST-1 composite photonic crystal thin layer can be prepared by taking an O ethanol solution and a trimesic acid ethanol solution with the concentration of 5mM as raw materials; zn (NO) at a concentration of 2mM3)2·6H2The ZIF-8 composite photonic crystal thin layer can be prepared by using an O methanol solution and a 2-methylimidazole methanol solution with the concentration of 5mM as raw materials. The photographs and the reflection spectra in FIG. 2 show that the three MOF-PC layers produced have uniform structural color and characteristic reflection signals of the photonic crystals. Scanning electron micrographs and X-ray diffraction images show that the surface of the colloidal particles is rough, and an MOF layer with a certain thickness can be grown really; the colloidal particle arrangement still presents a close-packed ordered structure, which shows that the layer-by-layer growth of the MOF material does not destroy the ordered arrangement of the colloid, and explains the structural color and the reflection signal of the composite photonic crystal thin layer. In addition, nitrogen adsorption and desorption experiments and X-ray diffraction patterns prove that the three MOF-PC thin layers also have high specific surface area and uniform microporesThe structure lays a foundation for absorption and desorption enhancement and selective adsorption.
EXAMPLE 3 determination of the location of sample points on Photonic Crystal thin layer plates Using spatially resolved reflectance Spectroscopy
The location of the chemical sample spot on the MOF-PC thin layer panel according to example 2 of the present invention can be directly observed by the naked eye or can be precisely determined by using Spatially Resolved Reflectance Spectroscopy (SRRS). In practice, the spectrometer fiber optic probe is typically mounted above the TLC plate and the sample is pulled at a constant rate of 2cm/min in the direction opposite to the sample development direction, allowing the spectrometer to continuously record the spectral changes of the MOF-PC lamella plate in the direction of sample development. The position of the sample can be determined by plotting a series of spectral data as a three-dimensional reflectance spectrum with the ratio shift value (Rf) as the x-axis, the reflectance wavelength as the y-axis, and the reflectance intensity as a color. As shown in FIG. 3, the reflectance signals at various locations on the chemistry-free MIL-100-PC lamella plates are completely identical, so that the SRRS pattern collected along the unfolding direction appears as a horizontal reflection band consisting of reflection peaks. When the sample point appears on the scanning path, the red shift of the reflection peak caused by the sample point can cause the bulge of the reflection band, and the position and the width of the bulge are completely consistent with the position and the trailing broadening of the sample point on the thin-layer plate, so that the Rf value of the substance can be more accurately determined through the SRRS atlas.
Example 4 migration of Single component cresol molecules on Metal organic framework composite Photonic Crystal thin layer plates
In order to verify that different chemical substances have different migration behaviors on the MOF composite photonic crystal thin-layer plate prepared by the invention, the development research of single component o-cresol or m-cresol on the HKUST-1, ZIF-8 and MIL-100 composite photonic crystal thin-layer plate is firstly carried out. In all six experiments, the volume ratio of the developing solvent was 5: 1, adding the mixed solvent of petroleum ether and ethyl acetate into a development cylinder until the depth is about 1 cm, and standing for a few minutes to ensure that the solvent steam is saturated. And (3) using a capillary to perform spotting on the MOF composite photonic crystal thin-layer plate to enable the diameter of the plate to be about 2mm, and transferring the spotted thin-layer plate into an unfolding cylinder for unfolding. And when the developing agent reaches a preset position, taking out the thin-layer plate, recording an image by using a digital camera, and simultaneously collecting a spatially resolved reflection spectrum along the developing direction by using a spectrometer.
The digital photograph in figure 4 shows that the unfolded o-cresol and m-cresol sample dots form a distinct structural color difference with the surrounding MOF composite photonic crystal lamellae, thus leaving visually discernable traces on the lamella plates. The spatially resolved reflectance spectra in FIG. 4 show more clearly that o-cresol and m-cresol exhibit different migration distances across the three MOF composite photonic crystal lamellae, with the m-cresol having specific migration values of 0.37, 0.40, 0.27 on the HKUST-1-PC, ZIF-8-PC, MIL-100-PC lamellae, and the o-cresol having specific migration values of 0.54, 0.53, 0.67, respectively, consistent with visual observations. Through comparison, the migration difference of the two cresol isomers on the MIL-100 composite photonic crystal thin layer is the largest, sample points are relatively concentrated, the tailing phenomenon is not obvious, and the separation of the cresol isomer mixture is expected to be realized under the same condition.
EXAMPLE 5 efficient separation of cresol isomer mixtures on MIL-100 composite Photonic Crystal thin layer plates
In order to verify that the thin-layer chromatography technology based on the MOF composite photonic crystal has high-efficiency separation capability, a cresol isomer mixture which is difficult to separate on the traditional thin-layer chromatography is selected as a research object, the MIL-100 composite photonic crystal thin layer prepared in the embodiment 2 of the invention is adopted as a stationary phase, the conditions in the embodiment 4 of the invention are adopted for development, and the actual separation effect of the isomer mixture is researched. In a typical experiment, the volume ratio of the developing solvent is 5: 1, adding the mixed solvent of petroleum ether and ethyl acetate into a development cylinder until the depth is about 1 cm, and standing for a few minutes to ensure that the solvent steam is saturated. The mixture of o-cresol and m-cresol with a volume ratio of 1:1 was spotted on the MOF composite photonic crystal thin layer plate by capillary to make the sample spot about 2mm in diameter, the spotted thin layer plate was transferred to a spreading cylinder for spreading, and the whole spreading process was recorded by a digital camera. And when the developing agent reaches a preset position, taking out the thin-layer plate, and collecting the spatially resolved reflection spectrum along the developing direction by using a spectrometer.
A series of digital photographs in fig. 5 show that the orange-yellow MIL-100 composite photonic crystal appears bright green due to the wetting of the solvent during the development process; and taking the developed thin layer plate out of the developing cylinder, and quickly recovering the MIL-100 composite photonic crystal to be orange yellow due to the volatilization of the solvent. At this time, since cresol molecules and a part of the solvent remain, the area carrying the sample spot appears green, and thus the positions of o-cresol and m-cresol can be directly observed and determined by the naked eye. The spatially resolved reflectance spectra in fig. 5 are in full agreement with the results of the digital photographs, and it is well demonstrated that cresol isomers can be effectively separated by a thin layer of MIL-100 composite photonic crystals.
The high-efficiency separation performance of the MIL-100 composite photonic crystal thin layer mainly comes from two aspects. One is that the high specific surface area enhances the adsorption and desorption process of the analyte on the thin-layer plate. The test shows that the specific surface area of MIL-100 is 1857m2(iv)/g, higher surface area than HKUST-1 and ZIF-8 (1365 m)2/g,1711m2/g) is also much higher than commercial SiO2Specific surface area of silica gel particles. And secondly, the MIL-100 has a pore window size and a pore channel structure which are most suitable for cresol isomer molecule diffusion and adsorption and desorption, so that the MIL-100 has good selectivity. Two staggered pore channels with different orientations exist in the MIL-100, the sizes of pore windows of the two staggered pore channels are respectively 0.86nm and 0.58nm, and the pore windows are matched with the size of cresol molecules, so that the MOF composite photonic crystal thin layer can selectively adsorb different cresol molecules, and the separation effect is further improved.
Example 6 comparison of the effectiveness of commercial silica gel thin layer chromatography with MOF composite Photonic Crystal thin layer chromatography in the separation of cresol isomers
In order to determine the separation effect of commercial silica gel thin layer chromatography on cresol isomers, a development study of o-cresol, m-cresol, and cresol isomer mixtures on commercial silica gel thin layer plates was performed, respectively. In the experiment, the volume ratio of 1: 0. 7: 1. 6: 1. 5: 1. 3: 1. 1:1, adding the mixed solvent of petroleum ether and ethyl acetate as a developing agent into a developing cylinder until the depth is about 1 cm, and standing for a few minutes to ensure that the solvent steam is saturated. The commercial silica gel thin layer plate was spotted by a capillary tube to have a diameter of about 2mm, and the spotted thin layer plate was transferred to an expansion cylinder for expansion. And (3) taking out the thin-layer plate when the developing agent reaches a preset position, placing the thin-layer plate under the irradiation of an ultraviolet lamp, and recording the position of the sample point by using a digital camera. As shown in fig. 6, the sample points after the development of o-cresol and m-cresol were very close under various developer conditions; thus when the mixture of the two is spread, there is a significant overlap of the o-cresol and m-cresol sample spots, forming a severely tailing sample spot, which makes it difficult to completely separate the cresol isomer mixture at all times.
As shown in fig. 7, in order to study the separation effect of different thin layer chromatography plates, 5: 1 the results of the development of petroleum ether and ethyl acetate developers on various thin layer plates, including the theoretical plate number, selectivity factor, degree of separation, etc., were compared. From the theoretical plate number, the plate numbers of the MOF composite photonic crystal thin-layer plate and the commercial silica gel chromatographic plate prepared by the invention are both about 100 and are far lower than those of a gas chromatography plate and a liquid chromatography plate, which is mainly because the diffusion distance of an analyte on the thin-layer chromatographic plate is short and is only 2-4 cm. Compared with the selectivity factor, the MIL-100-PC thin layer has the selectivity factor (2.51) of o-cresol and m-cresol higher than that of HKUST-1 and ZIF-8 composite photonic crystal thin layers (1.3-1.5), and is far higher than that of a commercial thin layer chromatographic plate (1.11). Therefore, the MOF composite photonic crystal thin layer prepared by the invention has a high selectivity factor, and is beneficial to separation of the two. In the actual separation, the separation degree of the cresol isomer in commercial silica gel thin-layer chromatography is only 0.33, and the effective separation cannot be realized; this is because the theoretical plate number of cresol on a thin layer of commercial silica gel and the selectivity factor for its p-cresol isomer are both low. When the MIL-100 composite photonic crystal thin layer is used as a fixed phase, the separation degree of cresol isomers reaches 1.96. The reason is that the MIL-100 composite photonic crystal thin layer has high selectivity to cresol isomers, the defect of low number of thin layer chromatography trays is effectively overcome, and efficient separation is realized within a short development distance.
Example 7 comparison of gas chromatography with MOF composite Photonic Crystal thin layer chromatography for separation of cresol isomers
The cresol isomer mixture is separated in a gas chromatograph, two completely separated chromatographic peaks can be observed in a chromatogram, and the separation degree is calculated to be 1.54, so that the gas chromatograph can realize effective separation of the cresol isomers. As shown in figure 7, the theoretical plate number of cresol molecules in a gas chromatographic column is as high as 20000, which is far higher than that of the cresol molecules in commercial silica gel thin-layer plates and MOF composite photonic crystal thin-layer plates. The selectivity factor of the gas chromatographic column for p-cresol isomers is only 1.05, is similar to that of a commercial silica gel thin layer plate, and is far lower than that of an MOF composite photonic crystal thin layer plate. It can be seen that commercial silica gel thin layer chromatography is unable to separate cresol isomers because of the lower number of plates and lower selectivity factor; the gas chromatography makes up for lower selection factors through extremely high layer plate number, and realizes the separation of cresol isomers; the MOF composite photonic crystal thin-layer chromatography compensates for lower layer plate number through higher selectivity factor, can separate cresol isomers, and even realizes higher separation degree than gas chromatography.
The protection of the present invention is not limited to the above embodiments. Variations and advantages that may occur to those skilled in the art may be incorporated into the invention without departing from the spirit and scope of the inventive concept, and the scope of the appended claims is intended to be protected.
Claims (8)
1. A preparation method of a metal organic framework material composite photonic crystal MOF-PC thin layer is characterized by comprising the following steps:
(1) SiO 2 containing silicon dioxide2Coating the supersaturated solution of colloidal particles on a substrate, and heating to obtain solid SiO2A photonic crystal thin layer; the heating process also comprises a high-temperature calcination step, wherein the high-temperature calcination temperature is 450-550 ℃; the high-temperature calcination time is 1-4 hours;
(2) recovering the above solid SiO2SiO in photonic crystal thin layer2Surface hydroxyl of colloidal particles, and then sequentially carrying out amino modification and carboxyl modification on the colloidal particlesDecorating to obtain carboxyl modified SiO2A photonic crystal thin layer;
in the step (2), the amino group is modified by: SiO that will restore surface hydroxyl2Soaking the photonic crystal thin layer in an ethanol solution containing Aminopropyltriethoxysilane (APTES) or an ethanol solution containing Aminopropyltrimethoxysilane (APTMS) for reaction; the volume fraction of aminopropyltriethoxysilane APTES or aminopropyltrimethoxysilane APTMS in the ethanol solution is 0.03-0.18%, the reaction temperature is 20-80 ℃, and the SiO for recovering the surface hydroxyl groups2The volume ratio of the photonic crystal thin layer to the solution is 1: (300-2000);
the carboxyl is modified into SiO modified by amino2Soaking the photonic crystal thin layer in dimethylformamide solution of succinic anhydride with the concentration of 0.0025-0.01g/mL for reaction, wherein the reaction temperature is 20-80 ℃, and the SiO modified by amino group2The volume ratio of the photonic crystal thin layer to the solution is 1: (300-2000);
(3) modifying the carboxyl group of the step (2) to obtain SiO2Alternately soaking the photonic crystal thin layers in a solution containing metal ions and a solution containing ligands, and growing the layers on the SiO by a layer-by-layer liquid phase growth method2Forming an MOF layer on the surface of the colloidal particles in situ to prepare the metal organic framework material composite photonic crystal MOF-PC thin layer;
the metal organic framework material composite photonic crystal (MOF-PC) thin layer is formed by depositing and wrapping MOF material on SiO2A composite photonic crystal thin layer is formed on the surface of the colloidal particles, and the MOF material is one or more of HKUST-1, ZIF-8 and MIL-100; the metal ion solution is Cu (CH)3COO)2·H2O ethanol solution, Zn (NO)3)2·6H2O methanol solution, FeCl3·6H2O ethanol solution; and/or the ligand solution is a trimesic acid ethanol solution and a 2-methylimidazole methanol solution.
2. The method of claim 1, wherein in step (1), the SiO-containing material is2The supersaturated solution of colloidal particles is SiO with the volume fraction of 20-40%2Colloidal particles and 60Percent-80 percent of colloidal particle supersaturated solution, wherein the solvent is an organic solvent and is selected from one or more of ethylene glycol, dimethyl sulfoxide, dimethyl formamide and propylene carbonate.
3. The method of claim 1, wherein in step (1), the temperature of the heating is 60 ℃ to 100 ℃; and/or the heating time is 10-120 minutes.
4. A metal organic framework material composite photonic crystal MOF-PC thin layer prepared by the method of any one of claims 1 to 3.
5. Use of a metal organic framework material composite photonic crystal MOF-PC thin layer according to claim 4 in high performance thin layer chromatography separation.
6. A thin layer chromatography separation method based on MOF-PC is characterized by comprising the following steps:
(1) spotting a solution containing an analyte on the MOF-PC thin layer plate of claim 4 to form a sample spot having a different structural color compared to the MOF-PC thin layer;
(2) transferring the MOF-PC thin-layer plate into an unfolding cylinder, waiting for an organic solvent to unfold the sample until the front edge of the unfolding agent reaches a preset position;
(3) taking the MOF-PC thin-layer plate out of the expansion cylinder, shooting a digital picture and collecting a spatial resolution reflection spectrum, determining the chromatographic parameters of each component in the analyte by using the structural color difference and the reflection spectrum signal difference of the sample point and the MOF-PC thin-layer plate, and determining the attribution of the separated sample point by referring to the interaction strength of each component and the stationary phase.
7. The method of claim 6, wherein in step (1), the analyte-containing solution is a methanol solution containing 30-60% o-cresol or m-cresol by volume fraction, an ethanol solution containing 30-60% o-cresol or m-cresol by volume fraction, or an aqueous solution containing 30-60% o-cresol or m-cresol by volume fraction.
8. The method of claim 6, wherein in step (3), the collection of the spatially resolved reflectance spectrum is performed by fixing a spectrometer fiber optic probe above the TLC plate, pulling the TLC plate in a direction opposite to the development direction at a constant rate of 1-4cm/min, so that the spectrometer can continuously record the change of the reflectance spectrum in the development direction; the spatially resolved reflectance spectrum refers to a three-dimensional reflectance spectrum in which the spread distance is represented by the x-axis, the reflection wavelength is represented by the y-axis, and the reflection intensity is represented by color.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010503057.9A CN111624296B (en) | 2020-06-05 | 2020-06-05 | High-efficiency thin-layer chromatography separation method based on metal organic framework material composite photonic crystal thin layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010503057.9A CN111624296B (en) | 2020-06-05 | 2020-06-05 | High-efficiency thin-layer chromatography separation method based on metal organic framework material composite photonic crystal thin layer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111624296A CN111624296A (en) | 2020-09-04 |
| CN111624296B true CN111624296B (en) | 2021-11-19 |
Family
ID=72259303
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010503057.9A Active CN111624296B (en) | 2020-06-05 | 2020-06-05 | High-efficiency thin-layer chromatography separation method based on metal organic framework material composite photonic crystal thin layer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111624296B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113637362B (en) * | 2021-09-09 | 2023-01-31 | 浙江理工大学 | Photocurable liquid photonic crystal color paste, preparation method and application thereof in construction of structural color generation film |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107462570A (en) * | 2017-08-03 | 2017-12-12 | 南京师范大学 | Photonic crystal modification microballoon and its application based on DNAzyme-aptamer chemoluminescence methods detection OTA |
| CN107505419A (en) * | 2017-08-03 | 2017-12-22 | 南京师范大学 | One kind is used to be enriched with, purify, detect AFB1Modification inverse opal photonic crystal microballoon and its preparation method and application |
| CN110346487A (en) * | 2019-07-18 | 2019-10-18 | 广西民族大学 | ZIF-8@ SiO2Core-shell particles and its preparation method and application |
| WO2020018767A1 (en) * | 2018-07-20 | 2020-01-23 | Northwestern University | An inorganic approach to rendering metal-organic frameworks electrically conductive |
-
2020
- 2020-06-05 CN CN202010503057.9A patent/CN111624296B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107462570A (en) * | 2017-08-03 | 2017-12-12 | 南京师范大学 | Photonic crystal modification microballoon and its application based on DNAzyme-aptamer chemoluminescence methods detection OTA |
| CN107505419A (en) * | 2017-08-03 | 2017-12-22 | 南京师范大学 | One kind is used to be enriched with, purify, detect AFB1Modification inverse opal photonic crystal microballoon and its preparation method and application |
| WO2020018767A1 (en) * | 2018-07-20 | 2020-01-23 | Northwestern University | An inorganic approach to rendering metal-organic frameworks electrically conductive |
| CN110346487A (en) * | 2019-07-18 | 2019-10-18 | 广西民族大学 | ZIF-8@ SiO2Core-shell particles and its preparation method and application |
Non-Patent Citations (4)
| Title |
|---|
| Fabrication of ZIF-8@SiO2 Core–Shell Microspheres as the Stationary Phase;Yan-Yan Fu et al.;《Chem. Eur. J.》;20131231;第19卷;"ABSTRACT"，第13484页右栏至第13485页左栏，第13490页"Experimental Section"节，Scheme 1 * |
| Hierarchically structured photonic crystals for integrated chemical separation and colorimetric detection;Qianqian Fu et al.;《Nanoscale》;20170221;第9卷;第2457页摘要，第2458页左栏第2段，第2458-2462页 * |
| Metal-Organic Frameworks for Thin-Layer Chromatographic Applications;Claudia Schenk et al.;《ACS Appl. Mater. Interfaces》;20161208;第9卷;"ABSTRACT"，第2006-2008页，图3 * |
| 生物硅光子晶体阵列应用于 TLC-SERS 分离检测食品及环境中违禁物;孔宪明 等;《第二十届全国光散射学术会议论文》;20191231;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111624296A (en) | 2020-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE60037267T2 (en) | SURFACE IMPROVED SPECTROSCOPIC ACTIVE COMPOSITE NANOPARTICLES | |
| Liu et al. | A review: Research progress of SERS-based sensors for agricultural applications | |
| Wang et al. | Coffee-ring effect-based simultaneous SERS substrate fabrication and analyte enrichment for trace analysis | |
| US10933654B2 (en) | Process for isotropic structural colour printing and an apparatus for detecting a target substance in the gaseous phase | |
| Lashgari et al. | Modification of mesoporous silica SBA-15 with different organic molecules to gain chemical sensors: a review | |
| Liu et al. | Molecularly imprinted optosensing material based on hydrophobic CdSe quantum dots via a reverse microemulsion for specific recognition of ractopamine | |
| Abolghasemi et al. | Three dimensionally honeycomb layered double hydroxides framework as a novel fiber coating for headspace solid-phase microextraction of phenolic compounds | |
| Abdolmohammad-Zadeh et al. | Ultratrace determination of arsenic in water samples by electrothermal atomic absorption spectrometry after pre-concentration with Mg–Al–Fe ternary layered double hydroxide nano-sorbent | |
| Sun et al. | Constructing a highly sensitivity SERS sensor based on a magnetic metal–organic framework (MOF) to detect the trace of thiabendazole in fruit juice | |
| CN111624296B (en) | High-efficiency thin-layer chromatography separation method based on metal organic framework material composite photonic crystal thin layer | |
| Yan et al. | DNA-functionalized photonic crystal microspheres for multiplex detection of toxic metal ions | |
| Huang et al. | Polyacrylic acid sodium salt film entrapped Ag-nanocubes as molecule traps for SERS detection | |
| Zanjanchi et al. | Rapid determination of aluminum by UV–vis diffuse reflectance spectroscopy with application of suitable adsorbents | |
| Shen et al. | On-site separation and identification of polycyclic aromatic hydrocarbons from edible oil by TLC-SERS on diatomite photonic biosilica plate | |
| CN107325227A (en) | A kind of preparation method and applications of graphene quantum dot | |
| Bai et al. | Responsive Amorphous Photonic Structures of Spherical/Polyhedral Colloidal Metal–Organic Frameworks | |
| CN103028351B (en) | Benzene sulfonic acid modified magnetic microsphere and preparation method and application thereof | |
| Liu et al. | Titanium dioxide-coated core-shell silica microspheres-based solid-phase extraction combined with sheathless capillary electrophoresis-mass spectrometry for analysis of glyphosate, glufosinate and their metabolites in baby foods | |
| Wang et al. | Super-hydrophilic SERS sensor with both ultrahigh activity and exceptional 3D spatial uniformity for sensitive detection of toxic pollutants | |
| Zhang et al. | Amorphous colloidal photonic crystals assembled by mesoporous silica particles for thin layer chromatography with high separation efficiency and colorimetric recognition | |
| Leng et al. | A molecularly imprinted photopolymer based on mesh TpPa-2 embedded with perovskite CsPbBr3 quantum dots for the sensitive solid fluorescence sensing of patulin in apple products | |
| Sciutto et al. | A new integrated TLC/MU-ATR/SERS advanced approach for the identification of trace amounts of dyes in mixtures | |
| DE19715484A1 (en) | Procedure for applying reagent spots | |
| Bell et al. | Quantitative SERS methods | |
| Ji et al. | Superhydrophilic molecularly imprinted polymers based on a single cross-linking monomer for the recognition of iridoid glycosides in Di-huang pills |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |