石墨烯/奈米鈀/離子液體複合電極之電化學感測性質研究

Electrochemical Sensing Performance of Graphene/Palladium/Ionic liquid Nanocompositie Electrodes

王覺漢(Chueh-Han Wang)

指導教授 ： 張仍奎

國立中央大學/工學院/材料科學與工程研究所/碩士(2012年)

摘要

本研究以石墨烯 (graphene)及多壁奈米碳管兩種奈米級碳材作為電化學感測的基材，感測物為抗壞血酸 (Ascorbic Acid)、多巴胺 (Dopamine)及尿酸 (Uric Acid)，為了增加感測的靈敏度及選擇性，利用超臨界流體技術，將鈀奈米顆粒均勻負載於碳材上，增加反應表面積，以單純碳材或將鈀奈米顆粒負載於碳材上的複合材料作為感測電極時，多壁奈米碳管的催化性質皆優於石墨烯；除了奈米顆粒外，另用也使用離子液體作為輔助，本實驗中使用六種離子液體1-ethyl-3-methylimidazolium thiocyanate (EMI-SCN)、1-butyl-1-methylpyrrolidinium bis(trifluoromethyl) sulfonyl imide (BMP-NTf2)、1-butyl-1-methylpyrrolidinium dicyanamide (BMP-DCA)、1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6 )、1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonyl imide (EMI-NTf2)及1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA)和碳材相混合，在離子液體輔助之下，電化學訊號獲得良好改善，且遠優於利用鈀奈米顆粒作為輔助，而碳材的優劣也呈現相反的行為，改以石墨烯優於多壁奈米碳管，為了進一步提升感測電極的靈敏度及選擇性，將碳材、鈀奈米顆粒及離子液體三者相結合，其結果卻未比單純碳材混合離子液體來的佳，此外，根據研究結果顯示，當利用離子液體作為輔助時，陰離子主導了電化學感測行為，依據增益效果排序為SCN- > DCA- > PF6- > NTF2-。
本研究中同時也以石墨烯為基材偵測葡萄糖，單純石墨烯並無法偵測葡萄糖，因此同樣以鈀奈米顆粒及離子液體作為輔助的材料，根據實驗結果，添加了鈀奈米顆粒後，可成功的偵測到葡萄糖，而僅有石墨烯及離子液體時則無法偵測到葡萄萄，但若將石墨烯、鈀奈米顆粒及離子液體三者相結合時則具加乘的效果，和偵測抗壞血酸、多巴胺及尿酸時呈現相反的結論，主要的原因為感測機制不同所造成，而離子液體的行為雖仍以陰離子主導，但增益的效果卻呈現相反的行為，依序為NTF2- > PF6- > DCA- > SCN-。
由實驗結果得知，對於不同的待測物可藉由石墨烯、鈀奈米顆粒及離子液體間的互相搭配，而達到最佳的偵測效果，顯示這三種材料運用於電化學感測器上的可行性。

關鍵字

石墨烯 ； 離子液體 ； 鈀

並列摘要

In this study, we use graphen-based and multiwall carbon nanotubes-based(MWCNT) materials as electrochemical sensing electrode to detect ascorbic acid(AA), dopamine (DA) and uric acid (UA). In order to enhance sensitivity and selective, nano-sized Pd catalyst particles are uniformly dispersed on both the carbon supports using a supercritical fluid deposition techniquein in which the MWCNT/Pd electrode shows higher detection current than that of the Graphene/Pd electrode. Besides Pd NPs, IL also utilized for application, the detection sensitivity of the Graphene/IL electrode is significantly promoted and noticeably outperforms that of the MWCNT/IL. Six different ILs are investigated in this research, including 1-ethyl-3-methylimidazolium thiocyanate (EMI-SCN), 1-butyl-1-methylpyrrolidinium bis (trifluoromethyl) sulfonyl imide (BMP-NTf2), 1-butyl-1-methylpyrroli dinium dicyanamide (BMP-DCA), 1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6 ), 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonyl imide (EMI-NTf2) and 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA). Both Pd NPs and IL could improve sensing performance, nevertheless, mixture of Graphene/Pd/IL electrode is not as good as graphene/IL electrode. The experimental result elucidated the cation dominate the sensing behavior as SCN- > DCA- > PF6- > NTF2-.
In the case of glucose, graphene cannot detect glucose in spite of IL existence, while Pd NPs supports act as catalyst can enhance performance. Especially Graphene/Pd/IL combination could improve sensing performance, the sensing behavior that also effected by cation, there are NTF2- > PF6- > DCA- > SCN-.
For simultaneous detection different analyte, the satisfactory selectivity and sensitivity can obtain by choosing suitable NPs or ILs that performs great potential in electrochemical sensing.

並列關鍵字

palladium ； ionic liquid ； graphene

參考文獻

1.Myung, Y., et al., Nonenzymatic Amperometric Glucose Sensing of Platinum, Copper Sulfide, and Tin Oxide Nanoparticle-Carbon Nanotube Hybrid Nanostructures. The Journal of Physical Chemistry C, 2009. 113(4): p. 1251-1259.

2.Chen, X.-m., et al., Nonenzymatic amperometric sensing of glucose by using palladium nanoparticles supported on functional carbon nanotubes. Biosensors and Bioelectronics, 2010. 25(7): p. 1803-1808.

3.Huang, K.-J., et al., Enhanced sensing of dopamine in the present of ascorbic acid based on graphene/poly(p-aminobenzoic acid) composite film. Colloids and Surfaces B: Biointerfaces, 2011. 88(1): p. 310-314.

4.Bao, Y., et al., Graphene Oxide-Templated Polyaniline Microsheets toward Simultaneous Electrochemical Determination of AA/DA/UA. Electroanalysis, 2011. 23(4): p. 878-884.

5.Mallesha, M., et al., Functionalized-graphene modified graphite electrode for the selective determination of dopamine in presence of uric acid and ascorbic acid. Bioelectrochemistry, 2011. 81(2): p. 104-108.