熒光碳點的制備及其在葉酸和環(huán)丙沙星檢測中的應用
發(fā)布時間：2019-06-09 23:05
【摘要】：碳點(Carbon dots,CDs)作為碳納米材料家族的一名新成員,由于其具有獨特的性質及潛在的應用價值,受到越來越多人的關注。相比于傳統(tǒng)的有機染料和半導體量子點,碳點不但繼承了碳納米材料原料廣泛、成本低的優(yōu)點,還具有制備簡單、易于修飾、發(fā)射波長可調諧、光穩(wěn)定性好、毒性低和生物相容性好等優(yōu)勢,同時在光、電催化等方面也具有特殊的性質。因此,碳點在分析檢測、催化、光電器件、生物傳感以及生物醫(yī)療等領域呈現(xiàn)出廣闊的應用前景。碳點的制備方法可以分為:自上而下法和自下而上法。自上而下法主要包括:超聲法,激光消融法,電化學法等。自下而上法主要有:模板法,硝酸回流法,微波法,水熱法等。本文從碳點的制備及其應用兩個方面出發(fā),尋找綠色環(huán)保的物質作為合成原料,探索碳點簡便快捷的制備方法,并研究其在葉酸和環(huán)丙沙星檢測中的應用。具體主要包括以下兩個方面:(1)以乳糖為碳源,在NaOH強堿溶液環(huán)境中,通過水熱法一步合成具有淡藍色熒光的碳點。隨后,對其進行以下表征:通過高分辨透射電子顯微鏡(HR-TEM)觀察,碳點的分散性好,平均粒徑約為2-3 nm;通過紅外光譜表征,碳點表面含有 CH2、 CH3、 OH和 COOH等官能團。由于碳點能與葉酸特異性結合,因此我們以碳點作為熒光探針用于檢測葉酸。其機理可能為:碳點表面的水溶性基團( OH和 COOH)和葉酸的親水官能團( OH、 COOH和 NH2)相互作用,形成氫鍵,促使碳點發(fā)生聚集,從而導致熒光猝滅。通過條件優(yōu)化,葉酸的濃度在6×10-5 mol/L-8×10-8 mol/L與碳點的熒光強度猝滅值呈線性相關,檢測限為1.2×10-9mol/L。此外,該體系用于人體尿液樣品中葉酸的檢測,回收率在96.7%-103.0%之間,說明本文建立的熒光分析方法能成功用于實際樣品中葉酸的檢測。葉酸,又稱維生素B9,是一種水溶性維生素,在人體的新生代謝扮演著重要的作用。一些疾病與葉酸的缺乏密切相關,例如:巨幼紅細胞性貧血,中風,心臟病發(fā)作,精神病,嬰兒畸形,癌癥等。因此,開發(fā)方便快捷的分析方法用于檢測葉酸,具有重要意義。(2)我們以羥丙纖維素(HPMC)作為碳源,通過水熱法制備了發(fā)藍色熒光的碳點。通過熒光光譜、高分辨透射電鏡、紫外-可見吸收光譜、紅外光譜、X射線光電子能譜等手段對其進行表征。碳點的粒徑大小約為5.6 nm,熒光量子產率為1.36%;最大激發(fā)波長和最大發(fā)射波長分別為310 nm和420 nm,同時發(fā)現(xiàn)碳點具有發(fā)射波長依賴于激發(fā)波長的性質;通過結構表征,發(fā)現(xiàn)碳點表面富含-OH和-COOH等水溶性官能團。利用碳點表面基團能與環(huán)丙沙星結合,建立了檢測環(huán)丙沙星的新方法。其線性范圍在10 nM-90μM之間,檢測限為5.88 nM(3σ),說明其檢測范圍較寬和靈敏度高,表明本文建立的熒光分析方法可以用于環(huán)丙沙星的檢測。環(huán)丙沙星是第三代喹諾酮類廣譜抗菌藥,由于其對革蘭性陽性菌和革蘭性陰性菌都有良好的效果,導致其在生物體殘留增多,所以對其痕量殘留進行檢測是一項很有意義的工作。
[Abstract]:Carbon dot (CDs), as a new member of the carbon nano-material family, has attracted more and more attention because of its unique nature and potential application value. Compared with the traditional organic dye and the semiconductor quantum dot, the carbon point not only inherits the advantages of wide raw material and low cost of the carbon nano-material, but also has the advantages of simple preparation, easy modification, tunable emission wavelength, good light stability, low toxicity and good biocompatibility, The electrocatalysis and the like also have special properties. Therefore, the carbon point has a wide application prospect in the fields of analysis detection, catalysis, photoelectric device, biological sensing and biological medical treatment. The carbon-point preparation method can be divided into top-down and bottom-up methods. The top-down method mainly includes the ultrasonic method, the laser ablation method, the electrochemical method and the like. The bottom-up method mainly includes the template method, the nitric acid reflux method, the microwave method, the hydrothermal method and the like. This paper, from the preparation of carbon point and its application, looks for green and environment-friendly materials as synthetic raw materials, and probes into the simple and rapid preparation method of carbon-point, and studies the application of it in the detection of folic acid and ciprofloxacin. The method mainly comprises the following two aspects: (1) using lactose as a carbon source, in a NaOH strong base solution environment, a carbon point with a light blue fluorescence is synthesized in one step by a hydrothermal method. It was characterized by high resolution transmission electron microscopy (HR-TEM) that the carbon point had a good dispersion and an average particle size of about 2-3 nm. The carbon-point surface was characterized by an infrared spectrum, and the carbon-point surface contained functional groups such as CH2, CH3, OH and COOH. Since the carbon point can be specifically combined with folic acid, we use a carbon spot as a fluorescent probe for the detection of folic acid. The mechanism may be that the water-soluble groups (OH and COOH) and the hydrophilic functional groups of the folic acid (OH, COOH, and NH2) interact with the hydrophilic functional groups (OH, COOH and NH2) of the folic acid to form hydrogen bonds, leading to the aggregation of the carbon points, leading to fluorescence quenching. The concentration of folic acid was in the range of 6-10-5 mol/ L-8 and 10-8 mol/ L, and the detection limit was 1.2-10-9 mol/ L. In addition, the system is used for the detection of folic acid in a human urine sample, and the recovery rate is between 96.7% and 103.0%, and the fluorescence analysis method established in this paper can be used for detecting the folic acid in the actual sample successfully. Folic acid, also known as vitamin B9, is a water-soluble vitamin, which plays an important role in the new metabolism of human body. Some diseases are closely related to the lack of folic acid, such as megaloblastic anemia, stroke, heart attack, psychosis, infant malformations, cancer, and the like. Therefore, it is of great significance to develop a convenient and fast analytical method for the detection of folic acid. (2) We used hydroxypropyl cellulose (HPMC) as a carbon source and prepared a carbon spot with blue fluorescence by a hydrothermal method. It is characterized by a fluorescence spectrum, a high-resolution transmission electron microscope, an ultraviolet-visible absorption spectrum, an infrared spectrum, an X-ray photoelectron spectrum, and the like. The carbon spot has a particle size of about 5.6 nm, a fluorescence quantum yield of 1.36%, a maximum excitation wavelength and a maximum emission wavelength of 310 nm and 420 nm, respectively, while finding that the carbon dot has a property of emission wavelength dependent on the excitation wavelength; and by structural characterization, It is found that the carbon-point surface is rich in water-soluble functional groups such as--OH and--COOH. And a new method for detecting ciprofloxacin is established by the combination of the carbon-point surface group and ciprofloxacin. The linear range is between 10 nM and 90. m u.M with a detection limit of 5.88 nM (3%), indicating that the detection range is wide and the sensitivity is high, indicating that the fluorescence analysis method established herein can be used for the detection of ciprofloxacin. Ciprofloxacin is a broad-spectrum antibacterial agent of the third generation, which has a good effect on the Gram-positive bacteria and the Gram-negative bacteria, and leads to the increase of the residue in the living body, so the detection of the trace residue is a significant work.
【學位授予單位】：西南大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O657.3;R927
本文編號：2495968
[Abstract]:Carbon dot (CDs), as a new member of the carbon nano-material family, has attracted more and more attention because of its unique nature and potential application value. Compared with the traditional organic dye and the semiconductor quantum dot, the carbon point not only inherits the advantages of wide raw material and low cost of the carbon nano-material, but also has the advantages of simple preparation, easy modification, tunable emission wavelength, good light stability, low toxicity and good biocompatibility, The electrocatalysis and the like also have special properties. Therefore, the carbon point has a wide application prospect in the fields of analysis detection, catalysis, photoelectric device, biological sensing and biological medical treatment. The carbon-point preparation method can be divided into top-down and bottom-up methods. The top-down method mainly includes the ultrasonic method, the laser ablation method, the electrochemical method and the like. The bottom-up method mainly includes the template method, the nitric acid reflux method, the microwave method, the hydrothermal method and the like. This paper, from the preparation of carbon point and its application, looks for green and environment-friendly materials as synthetic raw materials, and probes into the simple and rapid preparation method of carbon-point, and studies the application of it in the detection of folic acid and ciprofloxacin. The method mainly comprises the following two aspects: (1) using lactose as a carbon source, in a NaOH strong base solution environment, a carbon point with a light blue fluorescence is synthesized in one step by a hydrothermal method. It was characterized by high resolution transmission electron microscopy (HR-TEM) that the carbon point had a good dispersion and an average particle size of about 2-3 nm. The carbon-point surface was characterized by an infrared spectrum, and the carbon-point surface contained functional groups such as CH2, CH3, OH and COOH. Since the carbon point can be specifically combined with folic acid, we use a carbon spot as a fluorescent probe for the detection of folic acid. The mechanism may be that the water-soluble groups (OH and COOH) and the hydrophilic functional groups of the folic acid (OH, COOH, and NH2) interact with the hydrophilic functional groups (OH, COOH and NH2) of the folic acid to form hydrogen bonds, leading to the aggregation of the carbon points, leading to fluorescence quenching. The concentration of folic acid was in the range of 6-10-5 mol/ L-8 and 10-8 mol/ L, and the detection limit was 1.2-10-9 mol/ L. In addition, the system is used for the detection of folic acid in a human urine sample, and the recovery rate is between 96.7% and 103.0%, and the fluorescence analysis method established in this paper can be used for detecting the folic acid in the actual sample successfully. Folic acid, also known as vitamin B9, is a water-soluble vitamin, which plays an important role in the new metabolism of human body. Some diseases are closely related to the lack of folic acid, such as megaloblastic anemia, stroke, heart attack, psychosis, infant malformations, cancer, and the like. Therefore, it is of great significance to develop a convenient and fast analytical method for the detection of folic acid. (2) We used hydroxypropyl cellulose (HPMC) as a carbon source and prepared a carbon spot with blue fluorescence by a hydrothermal method. It is characterized by a fluorescence spectrum, a high-resolution transmission electron microscope, an ultraviolet-visible absorption spectrum, an infrared spectrum, an X-ray photoelectron spectrum, and the like. The carbon spot has a particle size of about 5.6 nm, a fluorescence quantum yield of 1.36%, a maximum excitation wavelength and a maximum emission wavelength of 310 nm and 420 nm, respectively, while finding that the carbon dot has a property of emission wavelength dependent on the excitation wavelength; and by structural characterization, It is found that the carbon-point surface is rich in water-soluble functional groups such as--OH and--COOH. And a new method for detecting ciprofloxacin is established by the combination of the carbon-point surface group and ciprofloxacin. The linear range is between 10 nM and 90. m u.M with a detection limit of 5.88 nM (3%), indicating that the detection range is wide and the sensitivity is high, indicating that the fluorescence analysis method established herein can be used for the detection of ciprofloxacin. Ciprofloxacin is a broad-spectrum antibacterial agent of the third generation, which has a good effect on the Gram-positive bacteria and the Gram-negative bacteria, and leads to the increase of the residue in the living body, so the detection of the trace residue is a significant work.
【學位授予單位】：西南大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O657.3;R927
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