基于纳米氧化锌复合材料的光电化学生物传感特性的研究

发布时间：2018-03-01 03:38

本文关键词： 光电化学 ZnO PLD 肿瘤标志物上转换发光　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：作为三大死亡杀手的癌症已成为疾病死因之首,且发病率和死亡率不断增加,严重威胁人类健康。但是癌症却并非等于死亡,癌症的早期检测对于临床诊断及治疗非常重要,而一般的检测方法和手段,难以进行早期准确检测。光电化学生物分析法可以对蛋白,核酸等与癌症相关生物物质进行低浓度的快速精确测定。此外,光电化学生物分析利用光学信号为激发信号,实行光电流的检测,兼具光学与电化学检测的优势,能够实现肿瘤标志物的高灵敏度检测。ZnO是第三代宽带隙半导体材料,具有优异的热学、化学性能,密度低,生物相容性好,光化学稳定性好等优点,ZnO纳米材料在光电化学生物分析中表现出优异的发展前景。另一方面,单独的纳米氧化锌电极对光的利用率低,只能吸收光谱中相当少部分的紫外光,而且易发生光生电子-空穴的复合,不利于制备高灵敏度的传感器,我们将采用基于纳米氧化锌的复合电极材料,制备具有优异传感性能的光电化学生物传感器。在此基础上,利用稀土离子具有深的穿透深度,大的斯托克斯位移,低的背景噪声与低毒性等优点。采用980nm激光器激发稀土材料,产生紫外光与可见光,从而激发纳米复合电极材料,这样避免了紫外光在光电化学生物检测系统中的影响。本文中,我们采用光电化学的检测手段,以基于氧化锌纳米复合材料为光电极,对肿瘤的标志物进行高灵敏快速检测。我们首先以模板法制备了三维大孔的纳米氧化锌材料电极,以激光脉冲沉积的方法制备了结构完整均匀的纳米氧化锌薄膜电极,然后分别利用窄带隙半导体材料(Ag_2S,CdS)进行复合,成功的制备了ZnO/Ag_2S复合电极与ZnO/CdS复合电极。在增加吸收光的同时,都能够实现两种电极结构的能级匹配,抑制光生载流子的复合,从而制备了低成本,高灵敏度,低检测限,宽检测范围,稳定性与特异性好的光电化学生物传感器,同时运用不同的激发光源,对肿瘤标志物甲胎蛋白进行了有效检测。(1)首先利用胶体晶体模板法在FTO玻璃上制备了三维大孔纳米氧化锌材料电极,然后利用连续离子层吸附反应在氧化锌反蛋白石大孔结构的框架与表面修饰了无毒的Ag_2S纳米粒子(NPs),制备了FTO/ZnO/Ag_2S复合电极,在氙灯的照射下对肿瘤标志物甲胎蛋白实现了低浓度无酶的光电化学高灵敏度检测,复合电极的检测限低达8pg/mL,线性范围为0.05ng/mL-200ng/mL。(2)采用激光脉冲沉积(PLD)的方法,依次在FTO玻璃基片上沉积了NaYF_4:Yb,Tm,ZnO,CdS,制备成FTO/NaYF_4:Yb,Tm/ZnO/CdS复合薄膜电极,在980nm激光的照射下,实现了低浓度甲胎蛋白的高灵敏度检测,检测的线性范围为0.01ng/mL-200ng/mL,检测限为5 pg/mL。采用窄带隙的纳米材料与氧化锌材料电极复合,提高了光的利用率,抑制了载流子的复合,从而制备出高灵敏度的生物传感器。我们对于两种结构氧化锌复合电极的光电性能进行了研究,并且采用不同的光源应用于检测肿瘤标志物甲胎蛋白。三维大孔的ZnO电极相对PLD方法制备的ZnO薄膜电极具有更高、更快的光电响应,更好的灵敏度。引入稀土离子的FTO/NaYF_4:Yb,Tm/ZnO/CdS复合薄膜电极,在980nm的激光激发下,ZnO/CdS能够最大的利用稀土的上转换发光,此光电化学检测系统对甲胎蛋白有更低的检测限和更宽的检测范围,该传感器对于未来光电化学生物应用与体内检测有更好的应用前景。
[Abstract]:As the three leading cause of death of cancer has become the first cause of disease, and the incidence and mortality increased, a serious threat to human health. But cancer is not equal to death, the early detection of cancer is very important for clinical diagnosis and treatment, detection methods and means in general, it is difficult to early detection of photoelectric chemical and biological analysis. Method for protein, nucleic acid and cancer related biological material for fast and accurate determination of low concentration. In addition, the photoelectric chemical and biological analysis by using optical signal as excitation signal, the detection of photocurrent, optical and electrochemical detection, high sensitivity detection of.ZnO can realize the tumor markers is the third generation wide band gap semiconductor material and have excellent thermal, chemical properties, low density, good biocompatibility, good photochemical stability, ZnO nano materials in photoelectrochemical biology Exhibit excellent prospects for development analysis. On the other hand, the low utilization rate of nano Zinc Oxide electrode alone to light, can only absorb ultraviolet light is less part of the spectrum, but also prone to electron - hole recombination, is not conducive to the preparation of high sensitivity of the sensor, we will use Zinc Oxide's nano composite electrode materials based on the photoelectrochemical biosensor preparation has excellent sensing performance. On this basis, with the penetration depth of deep utilization of rare earth ions, large Stokes shift, background noise and the advantages of low toxicity. Using 980nm laser excitation of rare earth materials, produce ultraviolet and visible light, so as to stimulate the nano composite electrode material, so to avoid the effect of UV in the photoelectric chemical and biological detection system. In this paper, we use the photoelectric detection means, based on the Zinc Oxide nano composite material for optical Electrode, markers of cancer by high sensitive and rapid detection. We first by template method to prepare nano electrode materials Zinc Oxide 3D macroporous, the method of pulsed laser deposition of nanometer thin film electrode structure of Zinc Oxide perfect preparation, and then use a narrow bandgap semiconductor materials (Ag_2S, CdS) compound, successful preparation of ZnO/Ag_2S composite electrode and ZnO/CdS composite electrode. The increase in the absorption of light at the same time, are able to achieve level two electrode structures, and inhibit the recombination of photogenerated charge carriers and thus produce low cost, the preparation of high sensitivity, low detection limit, wide detection range, photoelectrochemical biosensor with good stability and specificity at the same time, using different excitation sources, the tumor markers were effective detection. (1) first on FTO glass was prepared using three-dimensional macroporous oxide nano colloidal crystal template method The zinc electrode materials, and then use the SILAR in frame and surface Zinc Oxide inverse opal macroporous structure modified Ag_2S nanoparticles (NPs), non-toxic FTO/ZnO/Ag_2S composite electrode was prepared under Xe lamp irradiation on tumor markers can detect the photoelectrochemical high sensitivity of low concentration and no enzyme. The detection limit as low as 8pg/mL composite electrode, the linear range of 0.05ng/mL-200ng/mL. (2) by pulsed laser deposition (PLD) method, turn on the FTO glass substrate were deposited on NaYF_4:Yb, Tm, ZnO, CdS, FTO/ were prepared in NaYF_4:Yb, Tm/ZnO/CdS composite film electrode in 980nm laser irradiation, to achieve a high the sensitivity of detection of low concentration of AFP, the linear range of detection was 0.01ng/mL-200ng/mL, the detection limit is 5 pg/mL. with narrow band gap of nano materials and composite materials Zinc Oxide electrode, improves the utilization rate of light, suppression The recombination, thus preparing biosensor with high sensitivity. We studied the photoelectric properties of two kinds of structure of Zinc Oxide composite electrodes, and the use of different light source application in the detection of tumor markers. ZnO electrode 3D macroporous relative PLD method for preparing ZnO thin film electrode has a higher photoelectric, faster response, better sensitivity. The introduction of rare earth ions FTO/NaYF_4:Yb, Tm/ZnO/CdS composite film electrodes, under 980nm excitation, ZnO/CdS to maximum utilization of rare earth upconversion luminescence, the photoelectric detection system has lower detection limit and wide range of detection of AFP, the application prospect of this sensor have a better future for Photoelectrochemical applications and biological detection in vivo.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R730.4;TP212

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