阅读说明：本技术 基于硅量子点的荧光阵列传感器及其制备方法及应用 (Fluorescent array sensor based on silicon quantum dots and preparation method and application thereof ) 是由 黄略略 李彬 范大明 段续 梁勇 于 2020-06-05 设计创作，主要内容包括：本发明公开了一种基于硅量子点的荧光阵列传感器,其包括第一传感单元、第二传感单元和第三传感单元,其中第一传感单元由蓝色荧光硅量子点和Hg<Sup>2+</Sup>离子组成,第二传感单元由蓝色荧光硅量子点和Ag<Sup>+</Sup>离子组成,第三传感单元由蓝色荧光硅量子点和Cu<Sup>2+</Sup>离子组成。本发明还提供了所述基于硅量子点的荧光阵列传感器的制备方法。本发明还提供了所述基于硅量子点的荧光阵列传感器用于分析检测硫醇化合物的用途。本发明还提供了一种用于分析检测硫醇化合物的方法。本发明的阵列传感器用于检测硫醇化合物具有操作简便、成本低廉、无毒无害、生物相容性好、结果可靠、灵敏度高等优点。(The invention discloses a fluorescence array sensor based on silicon quantum dots, which comprises a first sensing unit, a second sensing unit and a third sensing unit, wherein the first sensing unit consists of blue fluorescence silicon quantum dots and Hg 2+ The second sensing unit is composed of blue fluorescent silicon quantum dots and Ag + The third sensing unit consists of blue fluorescent silicon quantum dots and Cu 2+ Ion composition. The invention also provides a preparation method of the fluorescent array sensor based on the silicon quantum dots. The invention also provides application of the fluorescent array sensor based on the silicon quantum dots to analysis and detection of thiol compounds. The invention also provides a method for analyzing and detecting thiolationA method of preparing the compound. The array sensor for detecting the mercaptan compound has the advantages of simple and convenient operation, low cost, no toxicity, no harm, good biocompatibility, reliable result, high sensitivity and the like.)

1. The fluorescence array sensor based on the silicon quantum dots comprises a first sensing unit, a second sensing unit and a third sensing unit, and is characterized in that the first sensing unit consists of blue fluorescence silicon quantum dots and Hg²⁺The second sensing unit consists of blue fluorescent silicon quantum dots and Ag⁺The third sensing unit consists of blue fluorescent silicon quantum dots and Cu²⁺Ion composition.

2. The silicon quantum dot-based fluorescence array sensor of claim 1, wherein the blue fluorescence silicon quantum dots are synthesized by a hydrothermal method.

3. The method for preparing a silicon quantum dot based fluorescence array sensor according to claim 1 or 2, comprising the steps of:

step 1: preparing a blue fluorescent silicon quantum dot use solution;

step 2: preparing a first sensing unit;

and step 3: preparing a second sensing unit;

and 4, step 4: a third sensing unit is prepared.

4. The method according to claim 3, wherein the blue fluorescent silicon quantum dots are prepared by the following steps: adding 0.56g of citric acid monohydrate into 4mL of deionized water for full dissolution, injecting 2mL of N- [3- (trimethoxysilyl) propyl ] ethylenediamine, vigorously stirring for 10min, reacting the mixed solution in a drying oven at 160 ℃ for 4h, naturally cooling to room temperature to obtain a blue fluorescent silicon quantum dot crude product, dialyzing the blue fluorescent silicon quantum dot crude product for 12h to obtain a blue fluorescent silicon quantum dot solution, centrifuging, filtering, and diluting by 10 times to obtain the blue fluorescent silicon quantum dot use solution.

5. The method of claim 3, wherein the first sensing unit is prepared by the steps of: preparing BF-SiQDs solution 200 μ L into 2mL solution with PBS buffer solution at pH 5.9, adding Hg²⁺30μM。

6. The method of claim 3, wherein the second sensing unit is prepared by the steps of: preparing BF-SiQDs solution 200 μ L into 2mL solution with PBS buffer solution, pH 8.0, adding Ag⁺100μM。

7. The method of claim 3, wherein the third sensing unit is prepared by the steps of: preparing BF-SiQDs use solution 200 μ L into 2mL solution with PBS buffer solution, pH 8.0, adding Cu²⁺100μM。

8. Use of the silicon quantum dot based fluorescence array sensor according to claim 1 or 2 for the analytical detection of thiol compounds.

9. A method for the analytical detection of thiol compounds, comprising the steps of: adding a thiol compound sample to the first sensing unit, the second sensing unit and the third sensing unit of the silicon quantum dot based fluorescence array sensor according to claim 1 or 2, respectively, and measuring a change in fluorescence signal intensity before and after the addition.

10. The method according to claim 9, wherein the thiol compound is added in the form of a solution having a concentration of 500 μ M.

Technical Field

The invention belongs to the field of organic chemistry, and particularly relates to a fluorescent array sensor based on silicon quantum dots, and a preparation method and application thereof.

Background

The sensor has wide application in industrial production, detection and scientific research, and has the advantages of low cost, high response speed, convenient use and the like. However, the conventional sensor only uses a single sensing unit, i.e., can only respond to a single message, and cannot simultaneously measure a plurality of detected objects. Although a single-channel sensor with a single sensing unit has strong selectivity for a specific substance, when the single-channel sensor is subjected to complex components or a sample contains multiple components with similar structures, the measurement is easily interfered, and the measurement result is deviated. In the field of analysis and measurement, various researches and applications put higher requirements on the aspects of measurement accuracy, reliability and the like of the sensor, and more efficient and reliable multi-dimensional information acquisition and processing modes are gradually favored by people. How to efficiently and reliably acquire information of analytes with complex components and utilize the information in actual detection work has become an important topic of analytical chemistry research.

The working principle of the array sensor is similar to that of animal olfaction, the object to be detected interacts with the array sensor, the sensing unit of the array sensor interacts with the object to be detected and responds, the chemical signal of the object to be detected is converted into an electric signal to be output, then the electric signal output by the array sensor is subjected to appropriate preprocessing, and finally pattern recognition is carried out through software analysis, so that the final discrimination result can be obtained. When a single sensing unit of the array sensor encounters different substances, different responses can be made, and meanwhile, when different sensing units encounter the same molecule, different responses can be made to each other, so that the array sensor is formed, and therefore the array sensor has the characteristics of broad-spectrum response and interactive response. Through the interactive response of different sensing units to different substances, after the array sensor responds to the test sample, the corresponding characteristic spectrum of each component in the detected object can be formed, thereby realizing the identification and detection of the specific substance. Therefore, the array sensor can simultaneously detect and identify a plurality of substances in the test object, compared with a single-channel sensor. Unlike conventional sensors using a single sensing element, the sensing element of the array sensor does not need to be particularly selective for a specific substance, but should satisfy the following requirements: the sensing unit has certain selectivity and can respectively make different responses when encountering a plurality of different substances; the sensing units have certain interaction sensitivity, namely, for the same sample, the same sensing unit can simultaneously generate responses with different components in the sample to different degrees; and thirdly, in order to ensure that the signal is stable enough in the measuring process, the chemical and optical properties of the sensing unit need to have better stability, and the service life of the array sensor can also be prolonged to a certain extent.

The fluorescent array sensor has the advantages of no need of a reference system, high sensitivity, various output signals (fluorescence intensity, maximum emission wavelength, spectrum shape, fluorescence lifetime, and the like), and the like, and has been the focus in the field of array sensor research in recent years. To construct a fluorescence array sensor with excellent performance, a sensing array needs to be constructed with good sensing units.

Quantum Dots (QDs), also known as semiconductor Nanocrystals (NCs), are quasi-zero-dimensional semiconductor nanomaterials with unique optical properties, the quantum dot molecules typically having a diameter of between 1 and 10nm and generally consisting of group II-VI, III-V and IV elements^[10]Common quantum dots include cadmium sulfide quantum dots, cadmium selenide quantum dots, cadmium telluride quantum dots, zinc sulfide quantum dots, zinc selenide quantum dots, lead sulfide quantum dots, carbon quantum dots, silicon quantum dots, and the like. Silicon quantum dots (SiQDs) are a quasi-zero-dimensional semiconductor nanomaterial with excellent optical properties, which not only possess unique photoelectric characteristicsIt has the advantages of no toxicity, no harm, low cost, photobleaching resistance, good biocompatibility, etc.

Quantum dot emission fluorescence is essentially a photoluminescence phenomenon. Quantum dots are semiconductor materials in which valence electrons are bound by covalent bonds. Under the irradiation of light with a specific wavelength, photons are absorbed by electrons on the valence band, and the electrons are excited to transit to the conduction band, and an equal amount of holes are generated. Due to instability of the electrons in the excited state at the conduction band, they will jump back to the valence band again to be trapped by the holes, while the energy absorbed when they jump to the conduction band is released as light radiation. Typical bulk semiconductor materials are more crystalline and therefore have deeper electron traps, which allows more electrons that transition from the valence band to the conduction band to be trapped by the electron traps, resulting in only a small fraction of electrons being able to transition back to the valence band and emit photons. Most electrons trapped by the electron trap are quenched in a non-radiative form, and only a small fraction of the electrons can return to the valence band by radiative transition or re-transit back to the conduction band after absorbing a certain amount of energy again. Therefore, the deeper the electron trap of the semiconductor material, the lower the light emission efficiency. Compared with bulk semiconductor materials, quantum dots have shallower electron traps and thus have stronger fluorescence performance.

Mercaptan refers to a kind of organic compound containing mercapto group, such as ethanethiol, coenzyme A, mercaptopropionic acid, etc. Besides, there are also common biological thiols such as various enzymes, peptides, biological membranes, and small molecule thiol compounds such as glutathione, cysteine, and homocysteine. Fluorescent probes, which have been the focus of research in recent years, are generally used to detect small molecule thiol compounds. The currently mature methods for detecting thiols include ultraviolet absorption, colorimetric, chemiluminescent, and fluorescent detection, as well as classical methods for detecting thiol compounds, such as electrochemical analysis and high performance liquid chromatography.

Disclosure of Invention

An object of the present invention is to provide an optical sensor for analyzing and detecting thiol compounds with good stability, high sensitivity and strong selectivity.

Another object of the present invention is to provide a method for manufacturing the above optical sensor.

It is a further object of the present invention to provide a method for the analytical detection of thiol compounds.

In order to achieve the above object, the present invention provides a silicon quantum dot-based fluorescence array sensor, which comprises a first sensing unit, a second sensing unit and a third sensing unit, wherein the first sensing unit is composed of blue fluorescent silicon quantum dots and Hg²⁺The second sensing unit is composed of blue fluorescent silicon quantum dots and Ag⁺The third sensing unit consists of blue fluorescent silicon quantum dots and Cu²⁺Ion composition.

Preferably, the blue fluorescent silicon quantum dot is synthesized by a hydrothermal method.

On the other hand, the invention also provides a preparation method of the fluorescent array sensor based on the silicon quantum dots, which comprises the following steps:

step 1: preparing a blue fluorescent silicon quantum dot use solution;

step 2: preparing a first sensing unit;

and step 3: preparing a second sensing unit;

and 4, step 4: a third sensing unit is prepared.

Preferably, the preparation steps of the blue fluorescent silicon quantum dot are as follows: adding 0.56g of citric acid monohydrate into 4mL of deionized water for full dissolution, injecting 2mL of N- [3- (trimethoxysilyl) propyl ] ethylenediamine, vigorously stirring for 10min, reacting the mixed solution in a drying oven at 160 ℃ for 4h, naturally cooling to room temperature to obtain a blue fluorescent silicon quantum dot crude product, dialyzing the blue fluorescent silicon quantum dot crude product for 12h to obtain a blue fluorescent silicon quantum dot solution, centrifuging, filtering, and diluting by 10 times to obtain the blue fluorescent silicon quantum dot use solution.

Preferably, the first sensing unit is prepared by the following steps: preparing BF-SiQDs solution 200 μ L into 2mL solution with PBS buffer solution at pH 5.9, adding Hg²⁺30μM。

Preferably, of said second sensing unitThe preparation steps are as follows: preparing BF-SiQDs solution 200 μ L into 2mL solution with PBS buffer solution, pH 8.0, adding Ag⁺100μM。

Preferably, the third sensing unit is prepared by the following steps: preparing BF-SiQDs use solution 200 μ L into 2mL solution with PBS buffer solution, pH 8.0, adding Cu²⁺100μM。

The invention also provides application of the fluorescent array sensor based on the silicon quantum dots to analysis and detection of thiol compounds.

The present invention also provides a method for the analytical detection of thiol compounds, comprising the steps of: and respectively adding a thiol compound sample into the first sensing unit, the second sensing unit and the third sensing unit of the fluorescence array sensor based on the silicon quantum dots, and measuring the intensity change of fluorescence signals before and after the thiol compound sample is added.

Preferably, the thiol compound is added as a solution at a concentration of 500. mu.M.

The electron-hole recombination efficiency of the quantum dots can change after the interaction between the analyte and the quantum dots, so that the fluorescence of the quantum dots is quenched or enhanced, and a single quantum dot can quench or enhance the fluorescence to different degrees after the interaction between the single quantum dot and different analytes, thereby realizing the identification of the analytes. Most of the water-soluble silicon quantum dots have a large number of amino groups and carboxyl groups, and can be used for identifying and analyzing specific substances. The array sensor can simultaneously identify and detect objects to be detected with various components, reduce interference of similar components and has better universality.

The blue fluorescent silicon quantum dots (BF-SiQDs) prepared by a hydrothermal method can be mixed with Hg²⁺、Ag⁺、Cu²⁺Fluorescence quenching is carried out in combination to form a sensing unit, and the fluorescence intensity of the sensing unit after the sensing unit and the thiol compound react is changed to different degrees. Based on the method, BF-SiQDs can be applied to the construction of a multichannel fluorescence array sensor for measuring trace thiol compounds. Hg based on blue fluorescent silicon quantum dots of the invention²⁺、Ag⁺、Cu²⁺The three-channel array sensor can effectively distinguish trace Glutathione (GSH) and Glutathione (GSH) in solutionCystine (CYS), mercaptopropionic acid (MPA), and the like.

In conclusion, the method for synthesizing BF-SiQDs by adopting the hydrothermal method is simple and convenient to operate, and the prepared BF-SiQDs have good optical performance, low cost, no toxicity, no harm, good biocompatibility, reliable result and high sensitivity.

Drawings

FIG. 1 is a schematic diagram of the process for the hydrothermal synthesis of BF-SiQDs.

FIG. 2 is a UV-VIS absorption spectrum of BF-SiQDs.

FIG. 3 is an infrared spectrum of BF-SiQDs.

FIG. 4 is a fluorescence spectrum of BF-SiQDs under excitation at a wavelength of 350 nm.

FIG. 5 is a characteristic fingerprint of three thiol compounds based on Hg-SiQDs single channel sensors.

FIG. 6 is a fingerprint of the characteristics of three thiol compounds based on Ag-SiQDs single channel sensors.

FIG. 7 is a characteristic fingerprint of three thiol compounds based on a Cu-SiQDs single channel sensor pair.

FIG. 8 is a fingerprint of three thiol compounds based on Hg-SiQDs, Ag-SiQDs, Cu-SiQDs three channel array sensors.

FIG. 9 is a LDA graph of three channel array sensors based on Hg-SiQDs, Ag-SiQDs, Cu-SiQDs in response to three thiol compounds.

FIG. 10 is a graph of HCA after three channel array sensors of Hg-SiQDs, Ag-SiQDs, Cu-SiQDs respond to three thiol compounds.

FIG. 11 is a schematic diagram of the principle of quenching and recovery of BF-SiQDs fluorescence.

Detailed Description

The present invention will be further described with reference to the following examples. It should be understood that the following examples are illustrative of the present invention only, and are not intended to limit the scope of the present invention.