茶叶中啶虫脒农药的纳米生物传感器检测方法研究

发布时间：2018-05-05 08:52

本文选题：茶叶 + 农药残留　；参考：《江苏大学》2017年硕士论文

【摘要】：茶叶享誉中外,是我国重要的农业经济代表作物,也是闻名遐迩的出口商品。然而,农药普遍施用,尤其是以啶虫脒(Acetamiprid,Ace)为代表的新型、高效农药,它们能有效防治虫害,残留量却引人忧思。常规的农残检测或适用局限,费时费力,或处理复杂,仪器昂贵,均不适用现场快速检测。核酸适配体合成成本低、识别特异性高;纳米材料响应灵敏、检测准确,研究将两者结合,克服常规检测的局限性,以啶虫脒为例,实现茶叶中农药残留快速灵敏检测。具体内容如下:1.上转换荧光纳米生物传感器对茶叶中啶虫脒的定量检测。在此,以上转换荧光纳米颗粒(Upconversion Nanoparticles,UCNPs)作供体,金纳米粒子(Gold Nanoparticles,GNPs)作受体,以静电作用使荧光共振能量转移体系(Fluorescence Resonance Energy Transfer,FRET)得以构建,并猝灭UCNPs的荧光。核酸适配体能够吸附到GNPs表面,维护GNPs在盐溶液中的稳定性;而当Ace存在时,核酸适配体能与其发生特异性结合并不再吸附到GNPs表面,GNPs因盐效应发生聚集,削弱FRET,UCNPs荧光恢复。在最优条件下,Ace于50 nM-1000 nM浓度区间与荧光比率成线性相关,检出限为3.2 nM;同时,对实际茶叶样本以标准加入法进行加标回收,所得结果准确可靠。该传感器以近红外作为激发光源,因此能够避免复杂样本的背景干扰,显示其在茶叶农药残留检测中的应用前景。2.表面增强拉曼纳米生物传感器对茶叶中啶虫脒的定量检测。在此,核酸适配体稳定GNPs在盐溶液的分散状态;拉曼活性结晶紫染料(Crystal Violet,CV)报告增强信号。当Ace存在时,核酸适配体能与其发生特异性结合并不再吸附到CV-GNPs表面,CV-GNPs因盐效应发生聚集,粒子间距减小,使得SERS信号借助粒子之间加强的表面等离激元耦合效应而显著增强,并在此以明显的CV特征峰作为标记峰进行测定。在最优条件下,Ace于30 nM-4000 nM浓度区间与拉曼强度差值成线性相关,检出限为17.6 nM;同时,对实际茶叶样本以标准加入法进行加标回收,所得结果准确可靠。该传感器以拉曼光谱作为检测曲线,操作简单测量方便,因此有望作为应用于茶叶中农药残留现场快速检测的候选方法。3.金比色纳米生物传感器对茶叶中啶虫脒的定量检测。在此,以核酸适配体作为Ace的识别元件,半胱胺盐酸盐修饰的金纳米粒子(Cysteamine-Gold Nanoparticles,CS-GNPs)作为比色指示剂。带负电的核酸适配体可以引起带正电的CS-GNPs的团聚,使CS-GNPs吸光值下降;而当Ace存在时,核酸适配体会优先与其发生特异性结合并形成复合物,不再诱导CS-GNPs团聚,使吸光值得到恢复。在最优条件下,Ace于10-40 nM浓度区间与吸收差值成线性相关,检出限为0.72 nM;同时,对实际茶叶样本以标准加入法进行加标回收,所得结果准确可靠。因此,该传感器在痕量范围检测表现出的超灵敏性可为茶叶农药残留的高精度检测提供借鉴。
[Abstract]:Tea is famous both at home and abroad, is the important agricultural economy representative crop, is also the famous export commodity. However, pesticides are widely used, especially new and efficient pesticides, such as Acetamiprid Aceas, which can effectively control insect pests, but their residues are worrying. Because of the limitation, time consuming, complicated processing and expensive instrument, the conventional detection is not suitable for rapid field detection. The synthesis of aptamer of nucleic acid has low cost and high recognition specificity. The nanomaterials are sensitive in response and accurate in detection. In order to overcome the limitations of conventional detection, the rapid and sensitive detection of pesticide residues in tea was realized by combining the two methods and taking acetamidine as an example. The details are as follows: 1. Quantitative determination of acetamiprid in tea by up-conversion fluorescent nanosensor. In this paper, the fluorescence resonance Resonance Energy transfer system (fluorescence Resonance Energy transfer system) was constructed by using gold nanoparticles (Gold Nanoparticles-GNPs) as the acceptor. The fluorescence resonance Resonance Energy transfer system was constructed, and the fluorescence of UCNPs was quenched. Nucleic acid aptamers can adsorb to the surface of GNPs to maintain the stability of GNPs in salt solution, but when Ace exists, nucleic acid adaptor can bind specifically to GNPs surface and no longer adsorb to GNPs surface, which weakens fluorescence recovery of GNPs due to salt effect. Under the optimal conditions, the fluorescence ratio was linearly correlated with the concentration range of 50 nM-1000 NM, and the detection limit was 3.2 nm. At the same time, the standard addition method was used to recover the actual tea samples, and the results were accurate and reliable. The sensor uses near infrared as the excitation light source, so it can avoid the background interference of complex samples and show the application prospect of the sensor in the detection of pesticide residues in tea. Surface enhanced Raman nanosensor for quantitative determination of acetamiprid in tea. The nucleic acid aptamer stabilizes the dispersion of GNPs in salt solution and the Raman active crystal violet dye Crystal Violet GNPs reports enhanced signal. In the presence of Ace, nucleic acid adaptations can bind specifically to CV-GNPs and no longer adsorb to the surface of CV-GNPs because of the aggregation of CV-GNPs due to the salt effect and the decrease of particle spacing, which makes the SERS signal significantly enhanced by the enhancement of the surface isophosphate coupling effect between the particles. The obvious CV characteristic peak was used as the marker peak. Under the optimal conditions, the concentration range of Ace at 30 nM-4000 nm was linearly correlated with the Raman intensity difference, the detection limit was 17.6 nm, and the standard addition method was used to recover the actual tea samples, and the results were accurate and reliable. The sensor takes Raman spectrum as the detection curve and is easy to operate, so it is expected to be used as a candidate method for rapid detection of pesticide residues in tea. Quantitative determination of acetamiprid in tea by gold colorimetric nano biosensor. Nucleic acid aptamer was used as the recognition element of Ace, and cysteamine-Gold Nanoparticles-CS-GNPs, modified by cysteamine-gold, was used as the colorimetric indicator. A negatively charged aptamer of nucleic acid can cause the aggregation of positively charged CS-GNPs and decrease the absorptivity of CS-GNPs, but when Ace exists, the aptamer of nucleic acid preferentially binds to it and forms a complex, which no longer induces the aggregation of CS-GNPs. Restore the absorptive value. Under the optimum conditions, the concentration range of Ace at 10-40 nm was linearly correlated with the absorption difference, and the detection limit was 0.72 nm. At the same time, the standard addition method was used to recover the actual tea samples, and the results were accurate and reliable. Therefore, the hypersensitivity of the sensor in trace detection range can be used for reference in high precision detection of pesticide residues in tea.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S481.8;TP212.3

【参考文献】