基于金银合金薄膜的近红外表面等离子体共振传感器研究  

Study of Au-Ag alloy film based infrared surface plasmon resonance sensors

作　　者：张喆[1] 柳倩[1] 祁志美[1] 

机构地区：[1]中国科学院电子学研究所,传感技术国家重点实验室,北京100190

出　　处：《物理学报》2013年第6期81-86,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60978042;61078039);国家重点基础研究发展计划(批准号:2009CB320300)资助的课题~~

摘　　要：利用淀积在玻璃衬底上的金银合金薄膜作为表面等离子体共振(SPR)芯片,构建了Kretschmann结构的近红外波长检测型SPR传感器.采用不同浓度的葡萄糖水溶液测试了金银合金薄膜SPR传感器的折射率灵敏度.实验结果表明随着入射角从7.5°增大到9.5°,SPR吸收峰的半高峰宽从292.8nm减小到131.4nm,共振波长从1215nm蓝移到767.7nm,折射率灵敏度从35648.3nm/RIU减小到9363.6nm/RIU.在相同的初始共振波长(λR)下获得的金银合金薄膜SPR折射率灵敏度高于纯金膜(纯金膜在λR=1215nm下的折射率灵敏度为29793.9nm/RIU).利用1μmol/L的牛血清蛋白(BSA)水溶液测试了传感器对蛋白质吸附的响应.结果表明,BSA分子吸附使得金银合金薄膜SPR吸收峰红移了12.1nm而纯金膜SPR吸收峰仅红移了9.5nm.实验结果还表明,在相同λR下,金银合金薄膜SPR吸收峰的半高峰宽大于纯金膜的半高峰宽,因此其光谱分辨率比纯金膜SPR传感器低.Au-Ag alloy films deposited on the glass substrates are used, for the first time, as a wavelength-interrogated near infrared surface plasmon resonance （SPR） sensor. The values of resonance wavelength （λR） of the sensor at different angles of incidence are determined by absorptiometry and its refractive-index （RI） sensitivity is investigated using aqueous glucose solutions as the standard RI samples. As the incident angle increases from 7.5° to 9.5°, the SPR absorption peak shifts from λR = 1215 nm to 767.7 nm, the full width at half magnitude （FWHM） of the peak reduces from 292.8 nm to 131.4 nm, and the RI sensitivity decreases from 35648.3 nm/RIU down to 9363.6 nm/RIU. At the same initial λR, the SPR sensor with the Au-Ag alloy film shows a higher sensitivity than that with the pure Au film （S = 29793.9 nm/RIU at λR=1215 nm with a pure Au film）. Adsorption of bovine serum album molecules from the aqueous solution of 1 μmol/L protein results in a redshift of ΔλR = 12.1 nm with the Au-Ag alloy film and ΔλR=9.5 nm with the pure Au film. The experimental data also indicate that the FWHM of the SPR absorption peak with the Au-Ag alloy film is larger than that at the same λR with the pure Au film, leading to a lower spectral resolution than that of the latter.

关 键 词：金银合金薄膜 表面等离子体共振 波长检测型 高灵敏度 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]