基于多功能化纳米复合材料超灵敏检测尿酸等含氮物质的研究

发布时间：2017-12-31 07:19

本文关键词：基于多功能化纳米复合材料超灵敏检测尿酸等含氮物质的研究　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：生命活动中重要的含氮代谢物如尿酸、神经递质如多巴胺和抗氧化剂如抗坏血酸等影响着人类生命活动过程中的代谢机制,尿酸含量异常会诱发系列代谢疾病,多巴胺的浓度变化则会影响人的神经系统,抗坏血酸则影响人体健康的生理机制。因此,开发高灵敏性、高特异性和精确的传感方法用于生命活动中的重要含氮物质和抗氧化剂等的定量或定性检测,对维护生命活动的正常进行显得非常重要。本论文结合多功能化的纳米复合材料,主要从事尿酸等含氮物质检测方面的研究工作,具体如下:(1)电化学还原氧化石墨烯/纳米金-壳聚糖复合膜修饰玻碳电极对尿酸的灵敏测定:将氧化石墨烯(GO)在玻碳电极(GCE)表面进行直接电化学还原,再组装上纳米金(AuNP)-壳聚糖(CS)聚阳离子,形成了ERGO/AuNP-CS复合膜修饰的玻碳电极。采用扫描电子显微镜(SEM)表征了不同修饰膜表面的形貌,探讨了其对尿酸(UA)分子的DPV行为,发现ERGO/AuNP-CS复合膜对UA分子表现出显著的电催化氧化活性。在0.10 mol/L的缓冲溶液(pH=6.5)中,扫速100mV/s时,该复合膜修饰电极对UA在浓度为0.0500~110μmol/L范围具有线性响应,检测下限为12.4 nmol/L(S/N=3)。该修饰电极具有良好的选择性、重现性和稳定性,可应用于人体血清和尿液样品中UA的测定,回收率达到93.8~104.1%。与分光光度法和尿酸酶试剂盒法相比较,测定结果一致。(2)功能化铂纳米-聚阳离子/电化学还原的氧化石墨稀复合膜用于尿酸和抗坏血酸的同时检测:制备了聚二烯二甲基氯化铵(PDDA)聚阳离子功能化的铂纳米(Pt NP)材料,将GO在GCE表面进行直接电化学还原,再组装上PtNP-PDDA复合膜,形成了功能化PtNP-PDDA/ERGO/GCE复合膜修饰的玻碳电极。采用透射电子显微镜(TEM)表征了不同浓度的聚阳离子功能化的铂纳米粒子,探讨了其对尿酸(UA)和抗坏血酸(AA)分子的DPV和CV行为,发现PtNP-PDDA/ERGO复合膜对尿酸(UA)和抗坏血酸(AA)分子表现出显著的电催化氧化活性及电分离作用,尿酸和抗坏血酸无需分离即可同时被检测出。在0.10 mol/L的缓冲溶液(pH=5.5)中,扫速为100 mV/s时,其对UA在浓度为0.025~20.0μmol/L范围具有线性响应,检测下限为7.2 nmol/L(S/N=3);对AA的浓度在为2.50~110μmol/L浓度范围内呈线性关系,检测下限为0.150μmol/L(S/N=3)。该修饰电极具有良好的抗干扰性、重现性和稳定性,可应用于人体血清样品中UA和AA的同时测定,回收率分别达到94.2~102.2%和96.9~105.4%。与尿酸酶试剂盒法和荧光光谱分析法相比较,测定结果令人满意,说明该修饰电极在生物医学领域有潜在的应用价值。(3)复合型碳纳米点-离子液体复合纳米材料的制备及同时测定尿酸和亚硝酸盐:结合多壁碳纳米管(MWCNTs)、离子液体([BMIM]BF4,IL)、氧化石墨烯(GO),采用超声法制备了一种新颖稳定的复合型氧化石墨烯碳点-碳纳米管碳点-离子液体(GQD-CQD-IL)的碳纳米点复合材料。利用透射电镜(TEM)对所合成的碳纳米点材料的形貌进行了表征,并研究了UA和NO2-同时存在于GQD-CQD-IL修饰电极上的CV特性,发现GQD-CQD-IL修饰电极良好的电催化氧化性能。对尿酸(UA)和亚硝酸盐(NO2-)分析检测的线性范围分别为0.15~20.0μmol/L,0.20~30.0μmol/L,检测限(S/N=3)分别为0.0062μmol/L,0.036μmol/L。应用于实际样品中UA和NO_(2-)测定,回收率分别为96.0%~101%,99.8%~102%,与尿酸酶试剂盒法和分光光度法相对比,实验测试结果令人满意,说明该修饰电极在生物分析检测领域有潜在的应用价值。(4)基于聚阳离子功能化的多壁碳纳米管(MWCNTs)高负载铂纳米粒子(PtNPs)复合膜对多巴胺的灵敏测定:用PDDA聚阳离子将多壁碳纳米管(MWCNTs)的表面进行功能化,再通过液相还原法成功地将PtNPs负载在MWCNTs的表面,构建了一种GCE/(MWCNT-PDDA/PtNPs)-Nafion修饰电极。使用TEM表征了不同的复合材料的形貌,探讨了修饰电极对DA的DPV和CV行为,研究发现MWCNT-PDDA/PtNPs复合膜对DA分子表现出良好的电催化氧化活性。实验结果说明,该修饰电极对多巴胺的电催化的线性范围为0.01~30μmol/L,检测限为2.5nmol/L(3S/N)。此外,该电极表现了较强的抗干扰能力、良好的重现性和稳定性。这种集碳纳米管、聚合电解质及贵金属纳米粒子为一体的纳米复合材料的构建为多巴胺高效灵敏的电化学检测提供了一个较好的研究平台。
[Abstract]:The life activities of important nitrogenous metabolites such as uric acid, neurotransmitters such as dopamine and antioxidants such as ascorbic acid affects the metabolism of human life in the process, the content of uric acid can induce a series of abnormal metabolic diseases, concentration of dopamine will affect the nervous system, affects the physiological mechanism of ascorbic acid in human body. Therefore, the development of high sensitivity, high specificity and accurate sensing method for quantitative or qualitative detection in the life activity of important nitrogenous substances and antioxidant, to maintain the normal activity of life is very important. This paper combines the nanocomposite functional, the main research work, engaged in uric acid nitrogen detection the details are as follows: (1) electrochemical reduction of graphene oxide / gold nanoparticles chitosan composite film glassy carbon electrode for the sensitive determination of uric acid: oxidation Graphene (GO) on a glassy carbon electrode (GCE) surface by direct electrochemical reduction, then assembled on gold nanoparticles (AuNP) - chitosan (CS) polycation, glassy carbon electrode to form ERGO/AuNP-CS composite film modified by scanning electron microscopy (SEM) characterization of the morphology of different surface modification, is discussed the uric acid (UA) DPV molecule, ERGO/AuNP-CS composite membrane of UA molecules exhibited electrocatalytic activity significantly. In the buffer solution of 0.10 mol/L (pH=6.5), scan rate 100mV/s, the composite membrane modified electrode to UA at the concentration of 0.0500~110 mol/L has a range of linear response, detection limit 12.4 nmol/L (S/N=3). The modified electrode has good selectivity, reproducibility and stability, can be applied to the determination of human serum and urine samples in UA, the recovery rate reached 93.8~104.1%. compared with the spectrophotometric method and urine acid enzyme reagent kit method, the determination results . (2) functionalized platinum nano polycation / electrochemical reduction of graphene oxide composite membrane for the detection of uric acid and ascorbic acid at the same time: preparation of polydiene two methyl ammonium chloride (PDDA) cationic poly platinum nano functional materials (Pt NP), GO on the surface of GCE by direct electrochemical reduction. Then the assembly of PtNP-PDDA composite membrane, forming a functionalized glassy carbon electrode PtNP-PDDA/ERGO/GCE composite film modified by transmission electron microscopy (TEM) characterization of platinum nanoparticles functionalized poly cation with different concentrations, to determine the uric acid (UA) and ascorbic acid (AA) molecules DPV and CV, found that PtNP-PDDA/ERGO composite film the uric acid (UA) and ascorbic acid (AA) molecules exhibit significant electrocatalytic activity and electric separation, uric acid and ascorbic acid without separation can also be detected. In the buffer solution of 0.10 mol/L (pH=5.5), Saul The speed is 100 mV/s, the concentration of UA in the 0.025~20.0 mol/L range with a linear response, a detection limit of 7.2 nmol/L (S/N=3); the AA concentration in 2.50~110 mol/L concentration range showed a linear relationship, detection limit of 0.150 mol/L (S/N=3). The modified electrode has good anti interference, reproducibility and stability, can be applied to the determination of UA and AA in human serum samples at the same time, the recovery rate reached 94.2~102.2% and 96.9~105.4%. with uricase Kit Method and fluorescence spectrum analysis method compared with satisfactory results, the modified electric potential application in biomedical field. (3) composite carbon nano - ionic liquid composite nano material preparation and determination of uric acid and nitrite: combination of multi walled carbon nanotubes (MWCNTs), ionic liquid ([BMIM]BF4, IL), graphene oxide (GO), was prepared by a novel ultrasound method The composite type graphene oxide carbon - stable carbon nanotube - ionic liquid (GQD-CQD-IL) carbon nano composites. By using transmission electron microscopy (TEM) morphology of carbon nano materials synthesized were characterized, and the effects of UA and NO2- exist in the GQD-CQD-IL CV characteristics of electrodes. Found that the electrocatalytic oxidation of GQD-CQD-IL modified electrode. The good of uric acid (UA) and nitrite (NO2-). The linear range of analysis were 0.15~20.0 mol/L, 0.20~30.0 mol/L (S/N=3) respectively, the detection limit is 0.0062 mol/L, the application of mol/ L. 0.036 in UA and NO_ in real samples (2-) were measured. The recovery rates were 96.0%~101%, 99.8%~102%, and uricase Kit Method and spectrophotometry were compared, the experimental results is satisfactory, indicating that the modified electrode has potential application value in the field of biological detection and analysis. (4) based on poly cationic The multi walled carbon nanotubes (MWCNTs) high load platinum nanoparticles (PtNPs) composite membrane for the sensitive determination of dopamine by PDDA cationic multi wall carbon nanotubes (MWCNTs) functionalized by surface by liquid phase reduction method PtNPs was successfully loaded on the surface of MWCNTs, constructed a GCE/ (MWCNT-PDDA/PtNPs -Nafion) modified electrode. TEM was used to characterize the different morphologies of the composites, discusses the modified electrode of DA DPV and CV, the study found that MWCNT-PDDA/PtNPs composite membrane of DA molecules exhibit good electrocatalytic activity. The experimental results show that the linear range of the modified electrode electrocatalysis to dopamine for 0.01~30. Mol/L, the detection limit is 2.5nmol/L (3S/N). In addition, the electrode has a strong anti-interference ability, good reproducibility and stability. This set of carbon nanotubes, polyelectrolyte and noble metal nanoparticles as a whole The construction of nanocomposite provides a good research platform for high efficient and sensitive electrochemical detection of dopamine.

【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O657.1;R446.12

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