以鎘金屬分析為例-探討金奈米粒徑及其間距形成之薄膜對化學電阻感測訊號之影響

Abstract

隨著台灣工業興起，重金屬汙染一直是備受關注的環境議題。目前一般傳統重金屬分析常利用的檢測方式包括:原子吸收光譜(Atomic absorption spectrometry)、原子放射光譜(Atomic emission spectrometry)、原子螢光光譜(Atomic fluorescence spectrometry)、誘導偶合共振電漿游離質譜法(ICP-MS) 等。雖然這些技術可以準確定量水中的重金屬離子，然而儀器昂貴且無法攜帶，因此近年來利用金奈米粒子感測重金屬離子的方式被廣泛的研究。除了金奈米粒子比色法之外，化學電阻感測器為近幾年開始發展的技術。該感測器具備可攜帶，低成本、即時量測等特性，但定量精準程度、離子選擇性、偵測極限有待進一步從感測器之表面修飾上進行改良與優化，因此本研究將著重探討改變金奈米粒子的粒徑、間距，如何影響化學電阻感測器訊號，使得以在最佳條件下進行水中重金屬(鎘)量測，並比較所開發之化學電阻感測器與比色法量測的優缺點，期望最終能提出適合進行重金屬測量的電阻式化學感測器條件(粒徑、間距)。

The heavy metal pollution owing to the rapid industrial development has been long an environmental issue which attracted lots of attention. Conventional heavy metal analysis usually can be achieved by atomic absorption spectrometry (AA), atomic emission spectrometry (AES), atomic fluorescence spectrometry (AFS), or inductively coupled plasma mass spectrometry (ICP-MS). These techniques provide reliable measurement in quantification of heavy metal ion; however, they are costly and are not portable, limiting the flexibility for quick in situ water testing. As a result, gold nanoparticle-based sensors have been extensively investigated to enable heavy metal ion analysis. Beside the well-known colorimetric methods, recently, chemiresistor sensor has become a newly developed analytical strategy. Although such type of sensors could be of mobile capabilities, cost-effectiveness and facilitates real-time monitoring, the improvements in the accuracy, selectivity and sensitivity are required, which potentially could be achieved by optimizing the surface modification of the devices. In this study we aimed to investigate the influence of the varied diameters and the interparticle distance of gold nanoparticles on resistance-based metal ion (Cadmium) detection. In addition, a comparison of the performance between the chemiresistor sensor and the colorimetric method was summarized. We foresee to eventually delineate optimized parameters (particle diameter and spacing) for the future AuNP-based heavy metal chemiresistor sensor development