熒光納米碳點的電化學(xué)制備及其在生化分析中的應(yīng)用
發(fā)布時間：2018-07-14 15:39
【摘要】：納米碳點(C-dots)是一種具有類似量子點光致發(fā)光性能的新型熒光碳納米材料。由于C-dots具有優(yōu)良的物化性質(zhì),在生物醫(yī)學(xué)、生化分析及光電催化等方面被廣泛應(yīng)用。目前,C-dots的合成還存在很多不足,如操作繁雜、條件苛刻及成本高等;在應(yīng)用方面,C-dots的諸多優(yōu)良性質(zhì)均未得到充分利用。因此,發(fā)展新的C-dots合成方法和拓展C-dots的應(yīng)用具有重要意義。電化學(xué)法制備納米材料具有合成可控、綠色及操作簡單等特點。本論文在簡要歸納C-dots的合成、發(fā)光性質(zhì)及生化應(yīng)用的基礎(chǔ)上,利用電化學(xué)手段合成了一系列具有出色發(fā)光性質(zhì)的C-dots,并基于這幾種C-dots不同的性質(zhì)構(gòu)建了幾種高性能的生物小分子傳感器,主要研究內(nèi)容如下:1.以石墨棒為碳源,在Na OH/水電解體系中,通過電化學(xué)氧化刻蝕快速合成了尺寸均一的C-dots。通過一系列表征手段,對制得的C-dots的內(nèi)部結(jié)構(gòu)及表面基團進行了分析�？疾炝思兯�、酸性、中性及堿性環(huán)境中電化學(xué)氧化刻蝕石墨棒制備C-dots的情況,發(fā)現(xiàn)適量的堿能增強電解過程中羥基自由基及氧自由基等氧化活性物質(zhì)的活性,從而提高對石墨棒的刻蝕效率,提高C-dots的制備效率。該法操作簡單且低耗高效,為電化學(xué)合成納米材料提供了重要借鑒。2.提出了一種新型以氧化石墨(GO)為原料大規(guī)模電化學(xué)制備石墨烯量子點(GQD)的方法。以GO水溶液為原料,Pt片為電極,不使用其他任何化學(xué)試劑,在純水中快速大批量制備了GQD,且其產(chǎn)率高達65.5 wt%。該法突破了傳統(tǒng)電化學(xué)制備GQD必須使用碳源用作刻蝕(工作)電極的局限,改進了其制備規(guī)模問題。制得的粗產(chǎn)物經(jīng)過簡單的處理后,可得到尺寸不同、熒光性質(zhì)不同的GQD。此外,制得的GQD擁有良好的類酶催化活性,能夠催化H2O2對四甲基聯(lián)苯胺的氧化�；诖�,成功用于檢測H2O2與葡萄糖。該法綠色環(huán)保且簡單高效,有望在GQD的實際生產(chǎn)中獲得應(yīng)用。3.首次利用了單一的簡單有機小分子作為碳源,建立了一種通過電化學(xué)碳化可控合成C-dots的新型電化學(xué)方法。與傳統(tǒng)電化學(xué)碳材料陽極氧化蝕刻制備C-dots不同,采用該法能在數(shù)小時內(nèi)合成大量高品質(zhì)的C-dots,且產(chǎn)物尺寸隨著碳化電壓的改變而變化。實驗結(jié)果表明,制得的C-dots粒子大小隨著電壓的增加而增大。本方法的優(yōu)點在于無需對產(chǎn)物進行繁瑣的修飾及純化處理,制得的C-dots的熒光量子產(chǎn)率(QY)高達14.9%。此外,成功地將制得的C-dots導(dǎo)入到宮頸癌細胞中,得到了標(biāo)識度高的細胞成像圖像。該法打破了傳統(tǒng)電化學(xué)氧化刻蝕碳素材料的理念,拓展了電化學(xué)手段在納米合成的應(yīng)用。4.利用電化學(xué)碳化手段,以乙醇胺為碳源合成了氮摻雜的C-dots(NC-dots)。制得的NC-dots具有出色的發(fā)光性質(zhì),且顯示出優(yōu)良的光穩(wěn)定性。基于NC-dots與Au NPs的相互作用,制備了NC-dots/Au NPs,構(gòu)建了同時擁有比色和熒光信號的半胱氨酸(Cys)傳感器。基于位阻效應(yīng),NC-dots/Au NPs可選擇性地與空間結(jié)構(gòu)較小的Cys反應(yīng),從而能將其與分子結(jié)構(gòu)較大的谷胱甘肽(GSH)進行區(qū)分。NC-dots/Au NPs對Cys具有良好的靈敏度和選擇性,其檢測限為4 n M,且運用標(biāo)準(zhǔn)加入法成功的對人血清中的Cys進行了檢測。該納米傳感器操作簡單、信號多元且直觀、靈敏度高、選擇性好,有望在生物分析等領(lǐng)域得到更廣泛的應(yīng)用。5.以乙二醇和乙二胺為前體,通過電化學(xué)碳化法制得具有優(yōu)良光性質(zhì)的NC-dots。基于Fenton反應(yīng),Fe2+存在下,H2O2能明顯地猝滅NC-dots的熒光。基于此,構(gòu)建了熒光傳感器用于葡萄糖的檢測。當(dāng)葡萄糖濃度為2-120μM時,NC-dots的熒光猝滅程度與葡萄糖濃度存在著良好的線性關(guān)系,其檢測限達到0.5μM。與醫(yī)用血糖儀進行比較,考察了該傳感器在實際樣品中的應(yīng)用,發(fā)現(xiàn)檢測結(jié)果與儀器所得結(jié)果相近。該檢測體系靈敏度高、選擇性好,豐富了C-dots的應(yīng)用。
[Abstract]:Nano carbon point (C-dots) is a new kind of fluorescent carbon nanomaterial, which has the properties of photoluminescence similar to quantum dots. Because of its excellent physical and chemical properties, C-dots has been widely used in biomedicine, biochemical analysis and photoelectrocatalysis. At present, there are many shortcomings in the synthesis of C-dots, such as complicated operation, harsh conditions and high cost; In application, many excellent properties of C-dots have not been fully utilized. Therefore, it is of great significance to develop new C-dots synthesis methods and expand the application of C-dots. The electrochemical synthesis of nanomaterials has the characteristics of synthesis and controllability, green and simple operation. This paper is a brief summary of the synthesis, luminescence properties and biochemical applications of C-dots. On the basis of this, a series of C-dots with excellent luminescence properties are synthesized by electrochemical method, and several high performance biological small molecular sensors are constructed based on the different properties of these C-dots. The main contents are as follows: 1. using graphite rods as carbon sources, the size is rapidly synthesized by electrochemical oxidation in the Na OH/ water electrolysis system. A C-dots. is used to analyze the internal structure and surface groups of the prepared C-dots by a series of characterization methods. The preparation of C-dots by electrochemical oxidation of graphite rods in pure water, acid, neutral and alkaline environment is investigated. It is found that a proper amount of alkali can enhance the oxidizing active substances such as hydroxyl radicals and oxygen radicals in the electrolysis process. In order to improve the etching efficiency of graphite rods and improve the preparation efficiency of C-dots, the method is simple and low consumption and high efficiency. It provides an important reference for the electrochemical synthesis of nanomaterials by.2.. A new method of large-scale electrochemical preparation of graphene quantum dots (GQD) with graphite oxide (GO) as raw material is proposed. GO water solution is used as the raw material and Pt GQD is prepared fast and large batch in pure water without any other chemical reagents, and its yield is up to 65.5 wt%.. The method breaks through the limitation of the traditional electrochemical preparation of GQD which must use carbon source as the etching (working) electrode, and improves the size of the preparation. After a simple treatment, the size of the produced crude product can be obtained in size. In addition, in addition to GQD. with different fluorescence properties, the prepared GQD has a good enzyme like catalytic activity and can catalyze the oxidation of H2O2 to four methylphenylamine. Based on this, it has been successfully used to detect H2O2 and glucose. This method is green and simple and efficient. It is expected to use.3. for the first time in the actual production of GQD with a single simple organic small molecule. As a carbon source, a new electrochemical method for the synthesis of C-dots by electrochemical carbonization is established. Different from the traditional anodic oxidation etching of the traditional electrochemical carbon materials to prepare C-dots, a large number of high quality C-dots can be synthesized in a few hours, and the size of the product changes with the change of the electric pressure of carbonization. The experimental results show that the obtained C- is made. The size of dots particles increases with the increase of voltage. The advantage of this method is that there is no need for complicated modification and purification of the products. The fluorescence quantum yield of C-dots (QY) is up to 14.9%., and the prepared C-dots is successfully introduced into the cervical cancer cells, and a highly marked cell imaging image is obtained. The concept of electrochemical oxidation etching of carbon materials has expanded the application of electrochemical means in nanoscale synthesis..4. uses electrochemical carbonization means to synthesize nitrogen doped C-dots (NC-dots) with ethanolamine as carbon source. The obtained NC-dots has excellent luminescence properties and shows excellent light stability. Based on the interaction of NC-dots and Au NPs, NC-dots/Au NPs is prepared, and a cysteine (Cys) sensor with both colorimetric and fluorescence signals is constructed. Based on the steric effect, NC-dots/Au NPs can selectively react with Cys with smaller spatial structure, so that it can distinguish the.NC-dots/Au NPs from the larger molecular structure of GSH and the.NC-dots/Au NPs is good sensitivity and selection for Cys. The detection limit is 4 N M, and the standard addition method is used to detect Cys in human serum successfully. The nano sensor is easy to operate, the signal is multiple and direct, the sensitivity is high, and the selectivity is good. It is expected to be used in the field of bioanalysis and so on,.5. with ethyl two alcohol and ethylenediamine as precursors, by electrochemical carbonization method NC-dots. with excellent light properties is based on Fenton reaction. In the presence of Fe2+, H2O2 can obviously quench the fluorescence of NC-dots. Based on this, the fluorescence sensor is used to detect glucose. When the glucose concentration is 2-120 u M, the fluorescence quenching degree of NC-dots is in a good linear relationship with the glucose concentration, and the detection limit is up to 0.5 u M.. Compared with the medical glucose meter, the application of the sensor in the actual sample was investigated. It was found that the detection result was similar to that of the instrument. The sensitivity of the system was high and the selectivity was good, and the application of C-dots was enriched.
【學(xué)位授予單位】：湖南師范大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TB383.1;O657.3
本文編號：2122121
[Abstract]:Nano carbon point (C-dots) is a new kind of fluorescent carbon nanomaterial, which has the properties of photoluminescence similar to quantum dots. Because of its excellent physical and chemical properties, C-dots has been widely used in biomedicine, biochemical analysis and photoelectrocatalysis. At present, there are many shortcomings in the synthesis of C-dots, such as complicated operation, harsh conditions and high cost; In application, many excellent properties of C-dots have not been fully utilized. Therefore, it is of great significance to develop new C-dots synthesis methods and expand the application of C-dots. The electrochemical synthesis of nanomaterials has the characteristics of synthesis and controllability, green and simple operation. This paper is a brief summary of the synthesis, luminescence properties and biochemical applications of C-dots. On the basis of this, a series of C-dots with excellent luminescence properties are synthesized by electrochemical method, and several high performance biological small molecular sensors are constructed based on the different properties of these C-dots. The main contents are as follows: 1. using graphite rods as carbon sources, the size is rapidly synthesized by electrochemical oxidation in the Na OH/ water electrolysis system. A C-dots. is used to analyze the internal structure and surface groups of the prepared C-dots by a series of characterization methods. The preparation of C-dots by electrochemical oxidation of graphite rods in pure water, acid, neutral and alkaline environment is investigated. It is found that a proper amount of alkali can enhance the oxidizing active substances such as hydroxyl radicals and oxygen radicals in the electrolysis process. In order to improve the etching efficiency of graphite rods and improve the preparation efficiency of C-dots, the method is simple and low consumption and high efficiency. It provides an important reference for the electrochemical synthesis of nanomaterials by.2.. A new method of large-scale electrochemical preparation of graphene quantum dots (GQD) with graphite oxide (GO) as raw material is proposed. GO water solution is used as the raw material and Pt GQD is prepared fast and large batch in pure water without any other chemical reagents, and its yield is up to 65.5 wt%.. The method breaks through the limitation of the traditional electrochemical preparation of GQD which must use carbon source as the etching (working) electrode, and improves the size of the preparation. After a simple treatment, the size of the produced crude product can be obtained in size. In addition, in addition to GQD. with different fluorescence properties, the prepared GQD has a good enzyme like catalytic activity and can catalyze the oxidation of H2O2 to four methylphenylamine. Based on this, it has been successfully used to detect H2O2 and glucose. This method is green and simple and efficient. It is expected to use.3. for the first time in the actual production of GQD with a single simple organic small molecule. As a carbon source, a new electrochemical method for the synthesis of C-dots by electrochemical carbonization is established. Different from the traditional anodic oxidation etching of the traditional electrochemical carbon materials to prepare C-dots, a large number of high quality C-dots can be synthesized in a few hours, and the size of the product changes with the change of the electric pressure of carbonization. The experimental results show that the obtained C- is made. The size of dots particles increases with the increase of voltage. The advantage of this method is that there is no need for complicated modification and purification of the products. The fluorescence quantum yield of C-dots (QY) is up to 14.9%., and the prepared C-dots is successfully introduced into the cervical cancer cells, and a highly marked cell imaging image is obtained. The concept of electrochemical oxidation etching of carbon materials has expanded the application of electrochemical means in nanoscale synthesis..4. uses electrochemical carbonization means to synthesize nitrogen doped C-dots (NC-dots) with ethanolamine as carbon source. The obtained NC-dots has excellent luminescence properties and shows excellent light stability. Based on the interaction of NC-dots and Au NPs, NC-dots/Au NPs is prepared, and a cysteine (Cys) sensor with both colorimetric and fluorescence signals is constructed. Based on the steric effect, NC-dots/Au NPs can selectively react with Cys with smaller spatial structure, so that it can distinguish the.NC-dots/Au NPs from the larger molecular structure of GSH and the.NC-dots/Au NPs is good sensitivity and selection for Cys. The detection limit is 4 N M, and the standard addition method is used to detect Cys in human serum successfully. The nano sensor is easy to operate, the signal is multiple and direct, the sensitivity is high, and the selectivity is good. It is expected to be used in the field of bioanalysis and so on,.5. with ethyl two alcohol and ethylenediamine as precursors, by electrochemical carbonization method NC-dots. with excellent light properties is based on Fenton reaction. In the presence of Fe2+, H2O2 can obviously quench the fluorescence of NC-dots. Based on this, the fluorescence sensor is used to detect glucose. When the glucose concentration is 2-120 u M, the fluorescence quenching degree of NC-dots is in a good linear relationship with the glucose concentration, and the detection limit is up to 0.5 u M.. Compared with the medical glucose meter, the application of the sensor in the actual sample was investigated. It was found that the detection result was similar to that of the instrument. The sensitivity of the system was high and the selectivity was good, and the application of C-dots was enriched.
【學(xué)位授予單位】：湖南師范大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TB383.1;O657.3
【參考文獻】
相關(guān)期刊論文 前1條
1 劉淼;刁偉力;吳迪;焦昕倩;李延莉;全福民;;羥自由基在電極電解過程中的形成規(guī)律[J];高等學(xué)�；瘜W(xué)學(xué)報;2005年12期
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