貴金屬奈米粒子感測器

Biosensors Based on Noble Metal Nanoparticles

許偉庭(Wei-Ting Hsu) ； 周禮君(Lai-Kwan Chau)

《科儀新知》 153期 (2006/08) Pp. 38-45

https://doi.org/10.29662/IT.200608.0004

摘要

貴金屬奈米粒子在吸收光譜中會產生特性吸收帶，此特性稱為定點化表面電漿共振波帶(localized surface plasmon resonance, LSPR)。其波長的位置與吸收度對外在環境的改變相當敏感。若要增加貴金屬奈米粒子的感測靈敏性，可以從粒子形狀作選擇，也可利用光波導多次內反射來增加光學路徑，同時也可透過貴金屬奈米粒子的表面官能化修飾增加感測器的選擇性。由於偵測是靠待分析物結合在奈米粒子的表面導致介電性質的改變，因此不必因為待測分析物沒有特殊的光譜特性（例如：螢光基團、發光團等）而需要額外進行標記的動作。

並列摘要

Noble metal nanoparticles exhibit a characteristic absorption band in the absorption spectrum, known as ”localized surface plasmon resonance (LSPR)”. The absorbance and peak wavelength of the LSPR band are linearly dependent on the refractive index of the surrounding medium. The sensing sensitivity can be increased by using nanoparticles of different shapes and by using waveguides to increase the optical path. The nanoparticles can also be functionalized to allow the selectivity of the sensor. Since the detection process is based on the change of refractive index of the surrounding medium when the analyte interacts with the molecular recognition group on the nanoparticle surface, the analyte does not require to have a spectroscopic signature (e.g. fluorophore, chromophore, etc.). Thus, noble metal nanoparticles can be used to construct label-free sensors.