基于石墨烯和生物条形码放大技术电化学检测两种重金属离子

发布时间：2018-06-18 07:23

本文选题：重金属离子 + 纳米金　；参考：《云南民族大学》2015年硕士论文

【摘要】：随着纳米技术的不断发展和进步,其本身优异的结合特性以及DNA分子识别能力已经被广泛应用于DNA传感器制备以及较多领域研究中,本文选择使用了石墨烯和纳米金两种常见的纳米材料,并结合生物条形码信号放大技术和酶催化反应技术,设计了用于检测环境水样中银离子和汞离子的电化学DNA传感器以及检测食品中过氧化氢的电化学传感器。1、设计了一个新颖、宽范围的基于生物条形码信号放大技术联合金标银染信号放大技术双重信号放大用于水溶液中银离子的检测的方法。该方法通过纳米金标记,表面杂交,银增强技术联用,实现电化学信号的放大,并通过银染时间的控制,以低背景峰电流检测超痕量银离子,检测范围宽,方法简单,具有较高的选择性和灵敏度。对Ag+的检测线性范围为5 p M到50μM,检出限为3 p M(S/N=3)。2、设计了一个简单、夹心结构的基于石墨烯和纳米金两种纳米材料,生物条形码信号放大技术、酶催化双重信号放大技术的电化学DNA传感器,用于在水溶液中检测汞离子。这一方法利用石墨烯作为高电子传递基底,同时存在汞离子和目标DNA的条件下,由于T?Hg2+?T结构的形成,使标记辣根过氧化物酶的纳米金-生物条形码DNA复合物与目标DNA形成特异性杂交双链,将与上百条生物条形码DNA结合的辣根过氧化物酶接近石墨烯表面,增强了催化对苯二酚的信号。所提出的电化学DNA传感器,在与其他金属离子共存情况下,具有较高的选择性和灵敏许,对Hg2+的检测线性范围为25 p M到10μM,检出限为13 p M(S/N=3)。3、制备了一个温和、信号切换、可重复使用的基于T?Hg2+?T的电化学生物传感器,依赖于石墨烯与单链DNA和双链DNA之间亲和力的差异。Fc标记的ss DNA能与目标DNA在Hg2+存在下特异性杂交形成ds DNA后脱离GR表面,降低了Fc的信号,使修饰电极理论上还原为石墨烯修饰的玻碳电极,实现修饰电极的重复利用。所提出的电化学DNA传感器,在与其他金属离子共存情况下,具有较高的选择性,起着信号放大作用的GR载体和游离到溶液中的ds DNA使传感器能进一步再次使用,具有较好的再生性。对Hg2+的检测线性范围为25 p M到10μM,检出限计算得5 p M(S/N=3)。4、制备了一种简单、新颖的无酶电化学传感器用于食品中过氧化氢的测定,将石墨烯优越的性能复合纳米二氧化钛形成协同催化作用,可控的在其表面生成普鲁士蓝纳米立方,并呈现规则边缘以及相近尺寸,并使用Nafion作为稳定剂。Nafion/PB/GR-Ti O2/GCE显示出良好的催化还原过氧化氢活性。检测线性范围为40 n M 2 m M,灵敏度为480.97 m A m M-1 cm-2,检测限为8.6 n M(S/N=3),并能应用到啤酒样品中的检测。
[Abstract]:With the development and progress of nanotechnology, its excellent binding properties and DNA molecular recognition ability have been widely used in the preparation of DNA sensors and in many fields of research. In this paper, two common nanomaterials, graphene and gold nanocrystalline, have been selected, combined with the technology of biological barcode signal amplification and enzymatic catalytic reaction. An electrochemical DNA sensor for the detection of silver and mercury ions in environmental water samples and an electrochemical sensor for the detection of hydrogen peroxide in food were designed. A wide range of Bio-barcode based signal Amplification techniques combined with Gold Standard Silver staining signal Amplification double signal Amplification for the Detection of Silver Ion in Aqueous solution. The method can amplify the electrochemical signal by means of nano-gold labeling, surface hybridization and silver enhancement technique. The method can be used to detect ultra-trace silver ions with low background peak current through the control of silver dye time. The detection range is wide and the method is simple. It has high selectivity and sensitivity. The linear range of detection for Ag is from 5 pm to 50 渭 M, and the detection limit is 3 p MN / N / N ~ (3). 2. A simple sandwich structure based on graphene and nano-gold nanomaterials, biological barcode signal amplification technique is designed. Enzyme-catalyzed double-signal amplification electrochemical DNA sensor is used to detect mercury ions in aqueous solution. In this method, graphene is used as the high electron transfer substrate, and under the condition of both mercury ion and target DNA, the formation of THg2 + T structure, The gold-biological barcode DNA complex labeled with horseradish peroxidase (HRP) was made to form a specific hybrid double strand with the target DNA, and the horseradish peroxidase (HRP) bound to hundreds of biological barcode DNA was close to the surface of graphene. The signal of catalytic hydroquinone was enhanced. The proposed electrochemical DNA sensor has high selectivity and sensitivity when it coexists with other metal ions. The linear range of detection for Hg _ 2 is from 25 pm to 10 渭 M, and the detection limit is 13 p M ~ (-1) S / N ~ (3) N ~ (3). 3. A mild, signal switching method has been prepared. A reusable electrochemical biosensor based on TG2 + T, dependent on the difference in affinity between graphene and single-stranded and double-stranded DNA. FC labeled ss DNA can specifically hybridize with target DNA in the presence of Hg2 to form DS DNA and detach from gr surface. The modified electrode can be reduced to glassy carbon electrode modified by graphene, and the modified electrode can be reused. The electrochemical DNA sensor proposed in this paper is highly selective in coexistence with other metal ions. The gr carrier, which is used for signal amplification, and DS DNA, which is dissociated into the solution, can be further reused. It has good regeneration. The linear range of detection for Hg _ 2 is from 25 pm to 10 渭 M, and the detection limit is calculated. A simple and novel enzymatic electrochemical sensor has been prepared for the determination of hydrogen peroxide in food. The superior performance of graphene was combined to form a synergistic catalysis to form a Prussian blue nano-cube on its surface, with regular edges and similar sizes. Nafion as stabilizer. Nafion / PBR-Ti O 2 / GCE showed good catalytic activity for hydrogen peroxide reduction. The linear range of detection is 40 nm M ~ (2 mm), the sensitivity is 480.97 m A m M ~ (-1) cm ~ (-2), the detection limit is 8.6n M ~ (-1) S ~ (-1) N ~ (-1) N ~ (3 +), and it can be applied to the detection of beer samples.
【学位授予单位】：云南民族大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP212;TB383.1

【相似文献】