本文選題：碳納米點(diǎn) + 亞硫酸鹽��； 參考：《華中科技大學(xué)》2015年碩士論文

【摘要】：碳點(diǎn)或碳量子點(diǎn),包括石墨烯量子點(diǎn)、碳納米點(diǎn)和聚合物量子點(diǎn),是一種近球形結(jié)構(gòu)的新型碳納米材料,具有諸多獨(dú)特的發(fā)光性能,包括發(fā)光穩(wěn)定、耐光漂白、熒光發(fā)射可調(diào)諧、低毒性、良好的生物相容性。目前,碳點(diǎn)已在諸如生物成像、化學(xué)傳感、納米藥物、光催化等領(lǐng)域得以成功應(yīng)用。本論文主要針對(duì)碳納米點(diǎn)的綠色合成和分析傳感應(yīng)用,開(kāi)展了以下研究工作:首先,以絲氨酸、聚乙二醇600和丙三醇為原料微波輔助合成碳納米點(diǎn)1,以檸檬酸和乙二胺為原料利用消解儀水熱法一步合成碳納米點(diǎn)2。實(shí)驗(yàn)分別對(duì)兩種碳點(diǎn)進(jìn)行了形貌和結(jié)構(gòu)表征進(jìn)而研究了兩種碳納米點(diǎn)的發(fā)光性能。實(shí)驗(yàn)證明,碳納米點(diǎn)1粒徑約為2~3 nm,單分散性好,穩(wěn)定性好,保存時(shí)間長(zhǎng);碳納米點(diǎn)2粒徑在20至30 nm之間,單分散性較碳納米點(diǎn)1差;兩種碳點(diǎn)均含有碳、氮、氧三種元素,分別以羥基、羧基和氨基等官能團(tuán)形式存在于碳點(diǎn)表面,碳納米點(diǎn)1中碳元素含量更高而碳納米點(diǎn)2表面分布有更多的羧基官能團(tuán);兩種碳點(diǎn)均具有良好的發(fā)光性能,pH、濃度和保存時(shí)間均會(huì)對(duì)碳點(diǎn)熒光造成影響。本文進(jìn)一步探討了碳點(diǎn)的發(fā)光機(jī)理,推斷碳點(diǎn)發(fā)光主要源于碳點(diǎn)表面電子-空穴的復(fù)合。依據(jù)碳納米點(diǎn)1在酸性條件(0.9 mol L-1HCl)下可有效敏化Na2SO3-KMnO4體系的化學(xué)發(fā)光,構(gòu)建了一種檢測(cè)亞硫酸鹽含量的化學(xué)發(fā)光新方法。方法的線性范圍是1.0×10-4~1.0×10-3 mol L-1,檢出限為5.1×10-5 mol L-1。此方法應(yīng)用于銀耳樣品中亞硫酸鹽含量的檢測(cè),方法加標(biāo)回收率為78%至88.3%。在研究Hg2+與納米點(diǎn)2相互作用時(shí)發(fā)現(xiàn),與文獻(xiàn)報(bào)道類(lèi)似,Hg2+可選擇性猝滅碳納米點(diǎn)2位于448 nm處的熒光,且熒光猝滅程度(F0/F)與Hg2+濃度成正比;此外,我們還發(fā)現(xiàn)納米點(diǎn)2在302nm處的吸收與溶液中所含Hg2+濃度亦成正比,這也是首次發(fā)現(xiàn)碳點(diǎn)的該性質(zhì)。據(jù)此,建立了熒光/比色法測(cè)定Hg2+的新方法。熒光法線性范圍是7.0×10-9~7×10-7 mol L-1,檢出限(3σ)為5.5×10-10mol L-1;比色法線性范圍1.0×10-9~7.0×10-7 mol L-1,檢出限(3σ)為5.7×10-10 mol L-1,分析性能堪比熒光法。將兩種方法應(yīng)用于水樣中Hg2+檢測(cè),兩種方法獲得的實(shí)驗(yàn)結(jié)果與原子吸收法實(shí)驗(yàn)結(jié)果相一致。加標(biāo)回收實(shí)驗(yàn)表明,熒光法回收率為99.8~100.2%,比色法回收率為100.2~101.4%。本文進(jìn)一步探討了化學(xué)發(fā)光法的增敏機(jī)理和熒光猝滅的機(jī)理。認(rèn)為碳點(diǎn)作為敏化劑,可有效吸收反應(yīng)能量,作為發(fā)光體發(fā)出明亮的化學(xué)發(fā)光,有效提升化學(xué)發(fā)光效率�？赡艿幕瘜W(xué)發(fā)光機(jī)理是:KMnO4為碳點(diǎn)注入空穴,同時(shí),高錳酸鉀自身被還原,生成Mn(II)*。Mn(II)*可與HSO3-反應(yīng)生成激發(fā)態(tài)HSO3-*,進(jìn)一步生成激發(fā)態(tài)SO2*。由于碳點(diǎn)具有獨(dú)特的表面性質(zhì),可以與上述激發(fā)態(tài)活性中間體發(fā)生反應(yīng),形成激發(fā)態(tài)碳點(diǎn),進(jìn)而產(chǎn)生明亮的化學(xué)發(fā)光。Hg2+與碳點(diǎn)之間的熒光猝滅作用為靜態(tài)猝滅。經(jīng)計(jì)算,它們之間的表觀結(jié)合常數(shù)K=1.29×108 L mol-1。汞離子與碳點(diǎn)之間可能發(fā)生了絡(luò)合作用,形成了全新的絡(luò)合物,從而使體系紫外光譜出現(xiàn)新的吸收峰,同時(shí)該過(guò)程消耗了部分碳點(diǎn),使得碳點(diǎn)熒光逐漸猝滅,表現(xiàn)為302 nm處的紫外吸收與448 nm處的熒光發(fā)射呈現(xiàn)此消彼長(zhǎng)的關(guān)系。
[Abstract]:Carbon dots or carbon quantum dots, including graphene quantum dots, carbon nanoscale points and polymer quantum dots, is a new type of carbon nanomaterials with near spherical structures. It has many unique luminescence properties, including luminescence stability, photobleaching, fluorescence emission tunable, low toxicity and good biocompatibility. At present, carbon points have been in biological imaging, chemistry. Sensing, nanometers, photocatalytic and other fields have been successfully applied. This paper focuses on the green synthesis and sensing applications of carbon nanodots. The following research work has been carried out. First, the microwave assisted synthesis of carbon nanoscale points with serine, polyethylene glycol 600 and glycerol as raw materials and the use of citric acid and ethylenediamine as raw materials for the digestion of water and heat. The morphology and structure of two carbon dots were characterized by the one step synthetic carbon nanodot 2. experiment. The luminescence properties of the two carbon nanodots were studied. The experimental results showed that the 1 particle size of carbon nanodots was about 2~3 nm, with good monodispersity, good stability and long preservation time; 2 particle size of carbon nanodots was 20 to 30 nm, and the monodispersity was worse than that of carbon nanoscale 1; two Three elements of carbon, nitrogen and oxygen are contained in the carbon, nitrogen and oxygen species, which exist on the surface of carbon point with hydroxyl group, carboxyl group and amino group respectively. The carbon nano point 1 has higher carbon content and more carboxyl functional groups on the surface of carbon nano point 2, and the two kinds of carbon points have good luminescence properties. PH, concentration and preservation time are all made to carbon point fluorescence. The luminescence mechanism of carbon point is further discussed. It is concluded that the luminescence of carbon point is mainly derived from the recombination of electron hole on the surface of carbon point. The chemiluminescence of Na2SO3-KMnO4 system can be sensitized effectively under the acid condition (0.9 mol mol), and a new chemiluminescence method for detecting sulfite content is constructed. The sex range is 1 x 10-4~1.0 x 10-3 mol L-1 and the detection limit is 5.1 x 10-5 mol L-1.. The method is applied to the determination of sulfite content in the samples of Tremella. The recovery rate of the method is 78% to 88.3%. when the interaction between Hg2+ and nanometer point 2 is studied. Similar to the literature report, the selectivity of Hg2+ is located at 448 nm at 448 nm. And the degree of fluorescence quenching (F0/F) is directly proportional to the concentration of Hg2+. In addition, we also found that the absorption of nanometer point 2 at 302nm is also proportional to the concentration of Hg2+ in the solution. This is the first discovery of the carbon point. According to this, a new method of fluorescence / colorimetric determination of Hg2+ is established. The linear range of fluorimetry is 7 * 10-9~7 x 10-7 mol L-1, detection limit (3). It is 5.5 x 10-10mol L-1; the linear range of the colorimetric method is 1 x 10-9~7.0 x 10-7 mol L-1, the detection limit (3 sigma) is 5.7 * 10-10 mol L-1, and the analysis performance can be compared to the fluorescence method. Two methods are applied to the Hg2+ detection in water samples. The experimental results obtained by the two methods are in accordance with the experimental results of the atomic absorption method. For 99.8~100.2%, the recovery rate of colorimetric method is 100.2~101.4%., the mechanism of sensitization and fluorescence quenching of chemiluminescence method is further discussed. It is considered that carbon point as a sensitizer can effectively absorb the reaction energy, emit bright chemiluminescence as a luminescent body and improve the efficiency of chemiluminescence. The possible chemiluminescence mechanism is KMnO4 The carbon point is injected into the hole, and at the same time, the Potassium Permanganate itself is reduced to produce Mn (II) *.Mn (II) *, which can react with HSO3- to generate excited state HSO3-* and further generate the excited state SO2*. because of its unique surface properties, which can react with the active intermediate of the excited state to form the excited state carbon point and then produce bright chemiluminescent.Hg2+. The fluorescence quenching between carbon points is static quenching. It is calculated that the apparent binding constant between them, K=1.29 * 108 L mol-1. mercury ion and carbon point may be complex, forming a new complex, which makes the UV spectra of the system new absorption peak, and the process consumes part of the carbon point, making the carbon point fluorescence by fluorescence. The gradual quenching shows that the ultraviolet absorption at 302 nm is related to the fluorescence emission at 448 nm.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：O613.71;TB383.1

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本文編號(hào)：2017730