本論文主要研究利用微波輔助溶液相沉積法(Microwave-assisted solution phase deposition, MW-SPD)成長大面積3-氨基丙基三乙氧基矽氧烷與聚二甲基矽氧烷表面處理之二氧化矽奈米顆粒混成感測膜(γ-APTES +NPs),批次製作超高靈敏度多晶矽線多巴胺感測器。我們研究在γ-APTES +NPs乙醇溶液中使用定功率90W微波輔助沉積γ-APTES +NPs感測薄膜,探討不同沉積時間與製程前、中、後使用紫外光(Ultraviolet,UV)照射及退火處理對薄膜特性的影響。為了推測二氧化矽奈米粒子與γ-APTES成功的混成γ-APTES +NPs複合薄膜,我們進行的分析包含原子力顯微鏡(Atomic force microscopy,AFM)觀察表面形貌,橢圓測厚儀(Ellipsometer)量測厚度,動態光散射儀(Dynamic Light Scattering ,DLS)量測γ-APTES混和二氧化矽奈米粒子之粒徑大小,利用顯微拉曼光譜儀(Microscopes Raman Spectrometer)分析光譜,以及X射線光電子能譜儀(X-ray Photoelectron Spectrometer, XPS) 分析薄膜表面元素。 以實驗結果顯示,以微波輔助溶液相沉積法可以大幅的降低γ-APTES +NPs薄膜的成長時間。其中單純以室溫溶液相沉積法成長γ-APTES +NPs,最佳的元件特性出現在沉積6小時,但以微波輔助成長最佳的元件特性出現在沉積15分鐘。多巴胺感測濃度可偵測範圍可從1×10-15 M ~ 1×10-3 M改善至1×10-20 M ~ 1×10-3 M,最低的偵測極限達1×10-20 M,最低偵測極限改善達5個數量級。若搭配UV光照射,則微波輔助溶液相沉積製程多巴胺感測濃度的可偵測範圍為1×10-24 M ~ 1×10-3 M,最低偵測極限改善達9個數量級。 薄膜退火處理方面,我們發現利用微波退火處理能大幅改善單純以室溫溶液相沉積法成長之γ-APTES +NPs特性,實驗結果顯示在室溫溶液相沉積法成長6小時之γ-APTES +NPs薄膜經15 min微波退火處理,多巴胺感測濃度可偵測範圍可從1×10-15 M ~ 1×10-3 M改善至1×10-21 M ~ 1×10-3 M,最低的偵測極限達1×10-21 M,最低偵測極限改善達6個數量級。 由拉曼分析不同沉積方式的薄膜結果顯示,只要製程中加了二氧化矽奈米粒子之後,Si-O-Si鍵結數變多而強度越強,其中以MW-SPD最明顯;我們在XPS分析也發現在Poly-Si chip上沉積γ-APTES和γ-APTES+NPs薄膜,γ-APTES+NPs表面Si元素百分比比γ-APTES大,證明二氧化矽奈米粒子與γ-APTES在SPD製程中形成混成奈米複合薄膜。而因為γ-APTES+NPs薄膜厚度在1~3nm,我們合理推論混入的二氧化矽奈米粒子外徑在1~3nm,提供感測薄膜超高的表面積/體積比,是元件具備超靈敏之最低偵測極限的主要原因。
In this thesis, microwave-assisted solution phase deposition (MW-SPD) method was used for growing the large-area sensing membrane of a 3-aminopropyltriethoxysilane (γ-APTES) and polydimethylsiloxane (PDMS)-treated silica nanoparticles mixture (γ-APTES+NPs) on polysilicon wires in the batch fabrication of dopamine biosensors. We investigated to grow the γ-APTES+NPs membrane using a solution contained mixture of γ-APTES+NPs and C2H5OH in a microwave oven with fixed power at 90 W. To characterize the film properties, γ-APTES+NPs films were prepared by MW-SPD with different deposit times or ultraviolet(UV) light exposure at different stages during deposition. The effects of microwave annealing on film property were also studied. In order to prove theγ-APTES were incorporated with silica nanoparticles during MW-SPD, we conducted the analyses including atomic force microscopy(AFM), ellipsometer, dynamic light scattering (DLS), micro-Raman spectroscopy and X-ray photoelectron spectrometer (XPS). It was found that MW-SPD could reduce the deposition time of γ-APTES+NPs significantly. The best deposition time for SPD at room temperature was 6 hours, but for the MW-SPD was only 15 minutes. The detectable range of the dopamine biosensor using γ-APTES+NPs as sensing membrane could be improved from 1×10-15 M ~ 1×10-3 M to 1×10-20 M ~ 1×10-3 M by MW-SPD process. The lowest detection limit was improved by 5 orders of magnitude. The UV illumination could further improve the biosensor with a detectable range of 1×10-24 M ~ 1×10-3 M. The lowest detection limit for dopamine was improved by 9 orders of magnitude for γ-APTES+NPs with MW-SPD+UV process.. As for the microwave annealing processes, we found that the sensitivity of the lowest detection limit for theγ-APTES+NPs prepared by the SPD could be significantly improved by the post microwave annealing treatment. For γ-APTES+NPs growing by a 6 hour SPD, a 15 minute microwave anneal could improve the detectable range from 1×10-15 M ~ 1×10-3 M to 10-21 M ~ 1×10-3 M. The lowest detection limit for dopamine was improved by 6 orders of magnitude. From Raman spectra of the membranes, enhanced absorption peaks of Si-O-Si bond were observed in all the films incorporated with silica NPs, especially for γ-APTES+NPs using MW-SPD process. The XPS analyses showed that the percentage of Si on the γ-APTES+NPs surface was larger than theγ-APTES. The silica nanoparticles were proved to be incorporated in γ-APTES during SPD. Because the thicknesses of γ-APTES+NPs membranes were in between 1nm and 3nm, it was reasonable to believe that the diameters of the incorporated silica nanoparticles were in the range of 1nm-3nm, resulting in ultra-high surface to volume ratio for the film and ultra-sensitive lowest detection limit for dopamine.