Investigations of the fabrication and the surface-enhanced Raman scattering detection applications for tapered fiber probes prepared with the laser-induced chemical deposition method.
Investigations of the fabrication and the surface-enhanced Raman scattering detection applications for tapered fiber probes prepared with the laser-induced chemical deposition method.
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DOI：
10.1364/ao.52.006163
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发表时间：
2013-09
期刊：
影响因子：
1.9
通讯作者：
Qunfang Fan;Jie Cao;Ye Liu;B. Yao;Q. Mao
中科院分区：
文献类型：
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作者：
Qunfang Fan;Jie Cao;Ye Liu;B. Yao;Q. Mao
本文研究了激光诱导化学沉积法（LICDM）在锥形光纤探针上沉积纳米粒子的过程，并对所制备探针的表面增强拉曼散射（SERS）检测性能进行了实验研究。我们的研究结果表明，用LICDM方法制备的纳米颗粒沉积的锥形光纤探针在很大程度上依赖于锥角的值。对于小角度锥形探针，由于锥面主要被相对低强度的倏逝场覆盖，纳米颗粒沉积区域仅集中在锥度尖端。通过延长反应时间或增加诱导功率或溶液浓度，仍有可能将纳米颗粒沉积在具有光散射效应的小角锥体上。以4-氨基噻吩为测试分子，在一定的制备条件下，不同激发激光功率下SERS光谱强度最高的锥形探针的锥角几乎相同。然而，这种最佳锥角是由局部表面等离子体共振强度和沉积的纳米颗粒产生的透射损失共同作用决定的。
The process of depositing nanoparticles onto tapered fiber probes with the laser-induced chemical deposition method (LICDM) and the surface-enhanced Raman scattering (SERS) detection performance of the prepared probes are experimentally investigated in this paper. Our results show that the nanoparticle-deposited tapered fiber probes prepared with the LICDM method depend strongly on the value of the cone angle. For small-angle tapered probes the nanoparticle-deposited areas are only focused at the taper tips, because the taper surfaces are mainly covered by a relatively low-intensity evanescent field. By lengthening the reaction time or increasing the induced power or solution concentration, it is still possible to deposit nanoparticles on small-angle tapers with the light-scattering effect. With 4-aminothiophenol as the testing molecule, it was found that for given preparation conditions, the cone angles for the tapered probes with the highest SERS spectral intensities for different excitation laser powers are almost the same. However, such an optimal cone angle is determined by the combined effects of both the localized surface plasmon resonance strength and the transmission loss generated by the nanoparticles deposited.