荧光纳米碳点的电化学制备及其在生化分析中的应用
发布时间：2018-07-14 15:39
【摘要】：纳米碳点(C-dots)是一种具有类似量子点光致发光性能的新型荧光碳纳米材料。由于C-dots具有优良的物化性质,在生物医学、生化分析及光电催化等方面被广泛应用。目前,C-dots的合成还存在很多不足,如操作繁杂、条件苛刻及成本高等;在应用方面,C-dots的诸多优良性质均未得到充分利用。因此,发展新的C-dots合成方法和拓展C-dots的应用具有重要意义。电化学法制备纳米材料具有合成可控、绿色及操作简单等特点。本论文在简要归纳C-dots的合成、发光性质及生化应用的基础上,利用电化学手段合成了一系列具有出色发光性质的C-dots,并基于这几种C-dots不同的性质构建了几种高性能的生物小分子传感器,主要研究内容如下:1.以石墨棒为碳源,在Na OH/水电解体系中,通过电化学氧化刻蚀快速合成了尺寸均一的C-dots。通过一系列表征手段,对制得的C-dots的内部结构及表面基团进行了分析。考察了纯水、酸性、中性及碱性环境中电化学氧化刻蚀石墨棒制备C-dots的情况,发现适量的碱能增强电解过程中羟基自由基及氧自由基等氧化活性物质的活性,从而提高对石墨棒的刻蚀效率,提高C-dots的制备效率。该法操作简单且低耗高效,为电化学合成纳米材料提供了重要借鉴。2.提出了一种新型以氧化石墨(GO)为原料大规模电化学制备石墨烯量子点(GQD)的方法。以GO水溶液为原料,Pt片为电极,不使用其他任何化学试剂,在纯水中快速大批量制备了GQD,且其产率高达65.5 wt%。该法突破了传统电化学制备GQD必须使用碳源用作刻蚀(工作)电极的局限,改进了其制备规模问题。制得的粗产物经过简单的处理后,可得到尺寸不同、荧光性质不同的GQD。此外,制得的GQD拥有良好的类酶催化活性,能够催化H2O2对四甲基联苯胺的氧化。基于此,成功用于检测H2O2与葡萄糖。该法绿色环保且简单高效,有望在GQD的实际生产中获得应用。3.首次利用了单一的简单有机小分子作为碳源,建立了一种通过电化学碳化可控合成C-dots的新型电化学方法。与传统电化学碳材料阳极氧化蚀刻制备C-dots不同,采用该法能在数小时内合成大量高品质的C-dots,且产物尺寸随着碳化电压的改变而变化。实验结果表明,制得的C-dots粒子大小随着电压的增加而增大。本方法的优点在于无需对产物进行繁琐的修饰及纯化处理,制得的C-dots的荧光量子产率(QY)高达14.9%。此外,成功地将制得的C-dots导入到宫颈癌细胞中,得到了标识度高的细胞成像图像。该法打破了传统电化学氧化刻蚀碳素材料的理念,拓展了电化学手段在纳米合成的应用。4.利用电化学碳化手段,以乙醇胺为碳源合成了氮掺杂的C-dots(NC-dots)。制得的NC-dots具有出色的发光性质,且显示出优良的光稳定性。基于NC-dots与Au NPs的相互作用,制备了NC-dots/Au NPs,构建了同时拥有比色和荧光信号的半胱氨酸(Cys)传感器。基于位阻效应,NC-dots/Au NPs可选择性地与空间结构较小的Cys反应,从而能将其与分子结构较大的谷胱甘肽(GSH)进行区分。NC-dots/Au NPs对Cys具有良好的灵敏度和选择性,其检测限为4 n M,且运用标准加入法成功的对人血清中的Cys进行了检测。该纳米传感器操作简单、信号多元且直观、灵敏度高、选择性好,有望在生物分析等领域得到更广泛的应用。5.以乙二醇和乙二胺为前体,通过电化学碳化法制得具有优良光性质的NC-dots。基于Fenton反应,Fe2+存在下,H2O2能明显地猝灭NC-dots的荧光。基于此,构建了荧光传感器用于葡萄糖的检测。当葡萄糖浓度为2-120μM时,NC-dots的荧光猝灭程度与葡萄糖浓度存在着良好的线性关系,其检测限达到0.5μM。与医用血糖仪进行比较,考察了该传感器在实际样品中的应用,发现检测结果与仪器所得结果相近。该检测体系灵敏度高、选择性好,丰富了C-dots的应用。
[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.
【学位授予单位】：湖南师范大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;O657.3
本文编号：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.
【学位授予单位】：湖南师范大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;O657.3
【参考文献】
相关期刊论文 前1条
1 刘淼;刁伟力;吴迪;焦昕倩;李延莉;全福民;;羟自由基在电极电解过程中的形成规律[J];高等学校化学学报;2005年12期
，本文编号：2122121
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