現今為止，pH感測器在環境監測、醫學診斷和工業流程等多個領域都有著重要的應用。儘管傳統的玻璃電極pH感測器可靠，但其易碎、微型化程度有限以及反應時間較長等問題仍待解決。因此研究可微型化的pH感測器是目前的主流。
一、
本篇的研究內容為製作氧化鋅奈米棒作為pH感測器，因為其具有堅固、可擴展且反應速度更快的特性，也因其獨特的性質如高電子遷移率、寬能帶差和大的激子束縛能量，而被廣泛研究。儘管如此，氧化鋅也存在著本質的缺陷，例如在某些極端的pH環境下，氧化鋅奈米棒可能會發生溶解或者結構變形，這會影響到感測器的穩定性和壽命。為了改善氧化鋅在物理上的限制，許多研究趨向於在氧化鋅不同架構下的表面以金屬奈米顆粒或有機聚合物做為表面修飾，本實驗選擇適用白金奈米顆粒濺鍍於奈米柱狀表面，並比較在不同酸鹼溶液中pH感測器的靈敏度和線性度。而本篇實驗室以擴展閘極場效應電晶體(EG-FET)的架構下進行量測。
首先，我們使用簡易的水溶液法進行了氧化鋅柱的成長，並經過一次退火，再以控制時間參數的方式鍍上不同數量的白金奈米顆粒於柱的表面，在氧化鋅奈米棒表面添加白金奈米顆粒，不僅提供了更多的活性位點，也增強了其對pH變化的靈敏度，也提高了其導電性，進一步提升了氧化鋅奈米棒作為pH感測器的性能。
實驗量測結果得知，柱狀的氧化鋅樣品其平均電流和電壓靈敏度為15.1?A pH-1 和48.1mV pH-1 另外線性曲線分別是0.946和0.964，而在經過白金的表面修飾後得到的平均電流和電壓最好的結果為91.3 ?A pH-1 和79.1 mV pH-1 對應到的線性度為0.968和0.991。此外，在Pt / ZnO NRs的樣品中都具有優越的輸出電壓響應，這說明了這些裝置作為pH感測器的可實行性。

Currently, pH sensors play a crucial role in various fields, including food safety monitoring, blood acid-base analysis and environmental analysis. Despite the reliability of traditional glass electrode pH sensors, issues such as fragility, limited miniaturization, and longer response time remain unsolved. Therefore, research on miniaturized pH sensors is currently mainstream.
This study focuses on the fabrication of Zinc Oxide (ZnO) nanorods as pH sensors due to their robust, scalable, and faster response characteristics. Owing to its unique properties such as high electron mobility, wide bandgap, and large exciton binding energy, ZnO has been widely studied. However, inherent defects in ZnO exist. For instance, ZnO nanorods may dissolve or deform structurally under certain extreme pH conditions, affecting the stability and lifespan of the sensor. To improve the physical limitations of ZnO, many studies tend to surface-modify different ZnO structures with metal nanoparticles or organic polymers. In this experiment, platinum nanoparticles were chosen for sputtering on the nanocolumn surface, and the sensitivity and linearity of the pH sensor in different acid-base solutions were compared. This experiment was conducted under the extended gate field-effect transistor (EG-FET) structure.
Initially, we grew the ZnO columns using a simple aqueous solution method, followed by annealing, and then sputtered different amounts of platinum nanoparticles on the column surface by controlling the time parameters. Adding platinum nanoparticles to the surface of ZnO nanorods not only provides more active sites but also enhances their sensitivity to pH changes, improves their conductivity, and further enhances the performance of ZnO nanorods as pH sensors.
The experimental measurement results show that the average current and voltage sensitivity of the columnar ZnO samples are 15.1 ?A pH-1 and 48.1 mV pH-1, respectively, and the linearity curves are 0.946 and 0.964, respectively. After platinum surface modification, the best average current and voltage obtained are 91.3 ?A pH-1 and 79.1 mV pH-1, corresponding to linearity of 0.968 and 0.991. Moreover, the Pt / ZnO NRs samples all have superior output voltage responses, demonstrating the feasibility of these devices as pH sensors.

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