摘要
在玻璃基片上溅射约50nm厚的金膜,在掺有P123聚合物的TiO2胶体溶液中浸渍提拉基片,经高温热处理后获得厚度约为210nm的TiO2纳米多孔薄膜。以此双层膜为漏模光波导芯片,并结合卤钨灯光源、CCD光谱仪、棱镜耦合器以及流动测试槽构建了基于Kretschmann结构的光谱测量式漏模光波导共振传感器。以非吸附型蔗糖水溶液为折射率液体,测试了传感器的折射率灵敏度。结果表明,在给定溶液折射率范围(1.3330～1.3557)内,漏模光波导共振波长随着折射率的升高而线形增大。以离子型表面活性剂和溴百里酚蓝为小分子吸附质,考察了传感器对小分子吸附的响应特性。结果表明,与只有一层金膜的SPR传感器相比,多孔薄膜漏模传感器对小分子吸附质的灵敏度大幅提高,这由于小分子在TiO2多孔薄膜导波层内的大量吸附。
Leaky-mode waveguides were prepared by sputtering a 50-nm gold layer on the glass substrate and then dip-coating on the substrate a 210-nm-thick TiO2 nanoporous film using the colloidal TiO2 solution mixed with P123 polymer. By using the waveguide chips combined with a tungsten-halogen lamp, a CCD spectrometer,a prism coupler and a fluidic chamber,spectral interrogated leaky-mode waveguide resonance sensor device with the Kretschmann configuration was constructed. The refractive-index sensitivity of the sensor was measured using aqueous sucrose solution samples. The results show that the resonance wavelength of the leaky-mode waveguide linearly increases with refractive index of the solution ranging from 1. 333 to 1. 356. The sensor response to small molecule adsorption was investigated by using ionic surfactant and bromthymol blue as adsorbate samples. The results indicate that the nanoporous leaky-mode waveguide resonance sensor is much more sensitive to small molecule adsorption than conventional surface plasmon resonance （ SPR） sensor. This high sensitivity results from adsorption of a large amount of small molecules in the nanoporous waveguiding layer.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2010年第11期1538-1543,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No.60978042)
国家重点基础研究发展计划项目(No.2009CB320300)
中国科学院"百人计划"择优支持项目资助
关键词
纳米多孔薄膜
漏模光波导
光谱灵敏度
小分子
Nanoporous thin film
Leaky-mode optical waveguide
Spectral sensitivity
Small molecule
