銀奈米離子壓電晶體感測器研製與應用

Preparation and Application of Piezoelectric Crystal Ion Sensor Based on Silver Nanoparticles

蔡佳怡(Chia-Yi Tsai)

指導教授 ： 施正雄

國立臺灣師範大學/理學院/化學系/碩士(2005年)

摘要

近幾年來，將奈米材料應用到化學感測器，這個領域正蓬勃發展。因為奈米粒子具有不同於塊材的化學性質與物理性質，奈米微粒吸附劑具有高表面積，可以有效吸附及偵測各種分子。本研究利用銀奈米當塗佈物研製出離子壓電晶體感測器，此感測器用來研究銀奈米與鹼金屬、鹼土金屬以及過渡金屬間的吸附作用。
本研究是以化學還原法製備銀奈米粒子，在冰浴環境下用硼氫化鈉當作還原劑來製備銀奈米，再利用Octadecylamine (ODA)當作界面活性劑將水相銀奈米轉到有機相，當作塗佈物。將塗佈銀奈米/PVC石英晶片作為研究銀奈米與各種金屬離子之間作用力，結果顯示金屬離子能被銀奈米所吸附並呈現不可逆的，可能為化學吸附現象。
探討塗佈銀奈米的石英壓電感測器與金屬離子之間的pH及干擾物效應。銀奈米與各種金屬離子作用最適合pH為8.03，在不同有機溶劑中或干擾物中，不同金屬離子干擾情形也不同。干擾比較大的使得銀奈米與金屬離子結合能力降低。其中各種金屬離子的偵測下限為鉀離子4.78×10-6M，鎂離子6.78×10-6M，銅離子2.94×10-6M，鋅離子4.71×10-6M，鎳離子3.30×10-6M，鉻離子7.70×10-7M。
將合成銀奈米粒子進行結構分析以及光譜分析，本研究利用TEM測出銀奈米粒子平均粒徑大小。並用SEM觀察塗佈在石英晶片上之奈米粒子表面的情形。本研究亦用光譜分析方面，探討水相中之銀奈米與各種金屬離子作用後的 UV-VIS光譜改變，可以發現到不同金屬離子與銀奈米作用後，吸收波長改變，溶液顏色也有所變化。
本研究所研製出來的銀奈米離子壓電晶體感測器，可以偵測不同金屬離子及探討金屬奈米和各種離子間之作用力。此銀奈米壓電感測器對各種金屬離子有很好的靈敏度與偵測下限。
關鍵字：壓電感測器、銀奈米、界面活性劑

關鍵字

銀奈米 ； 壓電感測器 ； 界面活性劑

並列摘要

The application of nanomaterials in the field of chemical sensors has become a new,growing area of interest in recent years.Because nanomaterials features that differ from bulk materials. Because of their greater surface area compaired with bulk material, nanomaterials can be applied as efficient adsorbents in chemical sensor for detecting target analyte.A piezoelectric quartz crystal sensor based on coated silver nanoparticles was set up to study the interaction between silver nanoparticles and various metal cation.
Silver nanoparticles were prepared by reduction of AgNO3 with NaBH4 in ice bath. Phase transfer of silver nanoparticles from aqueous to organic solutions using Octadecylamine (ODA) molecules as a surfactant. The partially irreversible response for cation was observed by desorption study,which implied that cation could be adsorbed on silver nanoparticlesby chemisorption.
Effects of pH and interfering species on the responses of silver nanoparticles coated piezoelectric crystal sensor for cation was studied.Optimum pH was found to be at 8.03 . There were difference that silver nanoparticles interact with various cations in different organic solvents and interfering species.The much interference resulted in, the less response change of the piezoelectric crystal sensor of interaction.The detection limit of various cations were 4.78×10-6M for K+ ion, 6.78×10-6M for Mg2+ ion, 2.94×10-6M for Cu2+ ion, 4.71×10-6M for Zn2+ ion, 3.30×10-6M for Ni2+ ion, 7.7×10-7M for Cr3+ ion.
Partical size of silver nanoparticles were measured by Transmission electron microscopy (TEM) and surface of coating silver nanoprticles on piezoelectric quartz crystalwas investigated by Scanning electron microscopy(SEM). The effects of cations on the absorption spectra of silver sols have been also investigated by the UV-VIS spectrometry.The interaction between silver nanoparticles and cations resulted in absorption wavelength red shift or blue shift and change in color of solution.

In conclusion, silver nanoparticles-immobilized piezoelectric crystal sensor can be applied for study of the interaction between silver nanoparticles and cations.The ion PZ sensor for cations basedon silver nanoparticl was successfully to detect various cations.The PZ sensor for cations exhibited good selectiveity and detection limit in aqueous solution.

Keyword: piezoelectric crystal sensor, silver nanoparticles, surfactant

並列關鍵字

Silver Nanoparticles ； piezoelectric crystal sensor ； surfactant