物联网-智慧传输-基于石墨烯量子点的荧光传感器的构建及应用.pdf

摘要

I

摘要

石墨烯量子点(Graphene quantum dot, GQDs)是石墨烯家族中的最新成员，也

是近三年来发展起来的一种准零维的纳米荧光材料。和传统的半导体量子点相

比，GQDs 具有生物相容性好，毒性低，光学性质稳定等优异的性能，在荧光传

感、细胞标记以及生物成像等方面具有广阔的应用前景。然而，目前基于 GQDs

的荧光传感分析仍处于初级阶段，在报道的文献中存在荧光量子产率低，荧光

传感敏感度低，选择性差等问题。因此，改进合成条件和传感体系的设计，以

供了方法学的参考和依据。具体内容如下：

1. 基于 GQDs 荧光传感法测定柠檬黄(tartrazine)

利用 Hummer 法，通过浓硫酸和高锰酸钾对石墨在高温条件下的氧化剥离，

合成 GO；采用 TOP-down的合成策略，以获得的 GO为碳源，浓氨水（浓 NH

3

·H

为碱性介质，在高温高压条件下（200 ℃ 反应 5 h），使 GO 去氧化并断裂成尺

寸较小的 GQDs，利用红外光谱（IR）和透射电镜（TEM）等对获得的 GQDs

进行了表征。该 GQDs 在 440 nm 具有较强的荧光，与柠檬黄的吸收光谱具有较

大程度的重叠，基于二者之间的内滤光效应，建立了柠檬黄的荧光传感分析新

方法。在最优的实验 条件下，柠檬黄的加入量与体系荧光的猝灭在 0.008

应 3 h，合成了 N-GQDs， 通过 IR，X 射线电子能谱（XPS），TEM 等对合成

的 N-GQDs 进行了表征；通过 Na

2

3

还原 KMnO

4

合成了 MnO

2

纳米片，MnO

2

摘要

纳米片在 N-GQDs 发射峰处具有较宽范围的光吸收，并且和 N-GQDs 之间具有

较强的 π-π 堆积作用，二者之间发生共振能量转移，从而猝灭 N-GQDs 的荧光；

AA 具有较强的还原性，可以将 MnO

2

恢复，基于此，建立了检测 AA 的荧光传感新方法，AA 的加入量在 0.02 μmol/L～

在上一章合成的 N-GQDs 的基础上，以 2-（N-吗啡啉）乙磺酸为还原剂合

成 MnO

纳米片通过 π-π 堆积，与 N-GQDs 发生共振能量转移，

N-GQDs 荧光猝灭，还原型的 GSH 能够将 MnO

2

还原成 Mn

,从而使得体系的荧

光恢复。基于此，建立了检测 GSH 的荧光传感新方法，相对于 Na

2

SO

3

还原合

成的 MnO

2

纳米片来说，该荧光能量转移体系对 GSH 具有更高的选择性。在

Graphene quantum dots (Graphene quantum dot, GQDs) is the newest member

of the graphene family, and also a quasi-zero-dimensional nano fluorescent material

developed the past three years. And compared to conventional semiconductor

quantum dots, GQDs has good biocompatibility, low toxicity, stable performance and

so on, also has broad applications in fluorescence sensing, cell labeling and biological

as fluorescence sensors to detect tartrazine, ascorbic acid and glutathione. Results

obtained from the GQDS fluorescent sensing system in application and analysis of

three kinds of target provides a methodology reference and basis. Details are as

follows:

1 A fluorescent sensor for tartrazine based on GQDs

Use Hummer method, by concentrated sulfuric acid and potassium

permanganate of graphite under the condition of high temperature oxidation stripping

to synthesis GO; Use the methods of TOP-down, the GO as carbon, concentrated

aqueous ammonia is alkaline medium at high temperature and pressure conditions

(200 ℃ 5 h), to make the GO oxidized and broken into smaller sizes GQDs, by

a lower detection limit and higher selectivity. Common metal ions and pigments do

not interfere with the determination system, the method can be successfully used for

the determination of tartrazine in drinks.

2 Based on fluorescence off-on of N-GQDs-MnO

Use the methods of Down-top, citric acid as a carbon source, ammonia as

nitrogen source, hydrothermal reaction 200 ℃ 3 h to synthesis the N-GQDs, by IR,

X-ray photoelectron spectroscopy (XPS), TEM to characterized N-GQDs; Got MnO

2

nanosheet by Na

SO

reduction KMnO

, MnO

nanosheet having a wide range of

fluorescence recovery. A new method for detecting AA is found. Under optimal

conditions, the detection linear range for ascorbic acid was found to be from 0.02

μmol/L to 8 μmol/L, the detection limit (LOD) was calculated as 0.0056 μmol/L

method not only has higher sensitivity, and can eliminate common interferences in

biological blood, such as uric acid (UA), dopamine (DA), glutathione (GSH). the

method has been successfully used to detect AA in blood sample, the recoveries is

96.5-102.7%.

3 Based on fluorescence off-on of N-GQDs-MnO

to Mn

, fluorescence

2

SO

reduction KMnO

4

, this methods has a higher selectivity for GSH. Under

V

Fluorescent sensors;