碳點/分子印跡聚合物修飾電極對雌二醇之電化學分析

Electrochemical Determination of 17-β-estradiol Based on Carbon Dots/Molecularly Imprinted Polymers Composites Modified Electrodes

劉德謙(Te-Chien Liu)

指導教授 ： 鄭淑華

國立暨南國際大學/科技學院/應用化學學系/碩士(2019年)

https://doi.org/10.6837/ncnu201900137

摘要

雌二醇(estradiol, E2)屬於一種天然雌激素(estrogen)，主要是由卵巢分泌的女性賀爾蒙，因其能有效解決掉髮治療禿頭，以及調整生理的功能，所以經常被添加於洗髮精或化妝品當中。然而過多的雌激素會擾亂人體的分泌、免疫及神經系統，為避免雌二醇的濫用，政府已經制定使用雌二醇的相關法令。因此，開發雌二醇的分析方法為一項重要的課題。
本研究利用碳點(carbon dots, Cdots)上附著分子印跡聚合物 (molecularly imprinted polymer, MIP)，修飾在網版印刷碳電極上，作為定量E2之電化學感測。材料的製備是利用微波輔助的方法合成碳點懸浮溶液，將其經過純化後配製成碳點乙醇溶液，再加入E2及合成MIP所需的功能單體APTES (3-aminopropyl)triethoxysilane)以及交聯劑TEOS (tetraethoxysilane)，利用溶膠-凝膠法(sol-gel method)合成出分子印跡聚合物與E2複合物(Cdots-MIP-E2)，再利用甲醇/醋酸溶液，反覆沖洗離心5次脫附E2，完成修飾材料Cdots-MIP。另外在合成時不添加E2的聚合物材料則稱為Cdots-NIP。所合成的Cdots利用傅立葉轉換紅外光譜(Fourier-transform infrared spectroscopy, FT-IR)來驗證其官能基；利用穿透式電子顯微鏡(Transmission electron microscope,TEM)驗證Cdots-MIP的結構。 Cdots-MIP材料分散在水中，再以滴覆的方式修飾到網版印刷碳電極上，製作出修飾電極SPCE/Cdots-MIP，電極的表面性質利用掃描式電子顯微鏡(Scanning Electron Microscopy, SEM)來驗證。電極的電化學性質是以循環伏安法(Cyclic voltammetry, CV)在1 mM K3Fe(CN)6溶液中，檢測其Cdots-MIP上孔洞之性質，由實驗結果可知SPCE/Cdots-MIP比 SPCE/Cdots-NIP對 K3Fe(CN)6有較佳的氧化還原電流，推測Cdots-MIP相較Cdots-NIP具有較多的孔洞，利於K3Fe(CN)6質傳至電極表面而偵測。最後利用浸泡的方式將修飾電極先在pH 8下吸附E2再利用差式脈衝伏安法(Differential Pulse Voltammetry， DPV)偵測，本分析方法對E2的靈敏度為3.87 μA/μM，E2的線性範圍為0.05 ~10 μM，偵測極限為0.013 μM。

關鍵字

電化學感測 ； 碳點 ； 分子印跡聚合物 ； 雌激素

並列摘要

Estradiol (E2) belongs to a natural estrogen (oestrogen), which is mainly produced by the ovaries. Because it can effectively treat the problem of hair loss and adjust physiological functions, it is often added to shampoo and cosmetics. However, excess estrogen can disturb the secretion, immunity and nervous system of the human body. To avoid the abuse of estradiol, the government has enacted laws and regulations on the use of estradiol. Therefore, the development of analytical methods for estradiol is an important issue.
In this study, carbon dots (Cdots) attached molecular imprinted polymer (MIP) was used as a modifying material on a screen-printed carbon electrode. A microwave-assisted method was used to synthesize a carbon dots suspension solution, which was added to a mixture containing E2 and the functional monomers of APTES (3-aminopropyl)triethoxysilane and cross-linker TEOS (tetraethoxysilane) to synthesize the molecularly imprinted polymer and E2 adduct by a sol-gel method. A methanol/acetic acid mixted solution was used to extract E2 by repeated washing for 5 times. In addition, the polymer material without E2 addition during synthesis is called Cdots-NIP. The synthesized Cdots were verified by Fourier Transform infrared spectroscopy (FT-IR); the physical structure of Cdots-MIP was verified by transmission electron microscope (TEM). The Cdots-MIP material was dispersed in water and then drop coated to screen-printed carbon electrodes. The surface properties of the modified electrode were verified by scanning electron microscopy (SEM). The electrochemical properties were measured by cyclic voltammetry (CV) in 1 mM K3Fe(CN)6 solution. The experimental results show that SPCE/Cdots-MIP exhibit a better redox peak for K3Fe(CN)6 than SPCE/Cdots-NIP did. It is speculated that Cdots-MIP has more pores than Cdots-NIP, which is beneficial for the mass transfer of K3Fe(CN)6 to the electrode surface. Finally, the modified electrode was employed to determine E2 at pH 8 by differential pulse voltammetry (DPV). The sensitivity of this analytical method to E2 was 3.87 μA/μM, and the linear range of E2 was from 0.05 μM to 10 μM. The detection limit is 0.013 μM.

並列關鍵字

Electrochemical sensor ； carbon dots ； molecularly imprinted polymer ； estradiol

參考文獻

參考文獻

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