Shao Jundong, Tong Liping, Tang Siying, Guo Zhinan, Zhang Han, Li Penghui, Wang Huaiyu, Du Chang, Yu Xue-Feng
SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University , Shenzhen 518060, P.R. China.
ACS Appl Mater Interfaces. 2015 Mar 11;7(9):5391-9. doi: 10.1021/am508881k. Epub 2015 Feb 26.
We report a new paper-based surface enhanced Raman scattering (SERS) substrate platform contributed by a poly(l-lactic acid) (PLLA) nanofibrous paper adsorbed with plasmonic nanostructures, which can circumvent many challenges of the existing SERS substrates. This PLLA nanofibrous paper has three-dimensional porous structure, extremely clean surface with good hydrophobicity (contact angle is as high as 133.4°), and negligible background interference under Raman laser excitation. Due to the strong electrostatic interaction between PLLA nanofiber and cetyltrimethylammonium bromide (CTAB) molecules, the CTAB-coated gold nanorods (GNRs) are efficiently immobilized onto the fibers. Such a hydrophobic paper substrate with locally hydrophilic SERS-active area can confine analyte molecules and prevent the random spreading of molecules. The confinement leads to focusing effect and the GNRs-PLLA SERS substrate is found to be highly sensitive (0.1 nM Rhodamine 6G and malachite green) and exhibit excellent reproducibility (∼8% relative standard deviation (RSD)) and long-term stability. Furthermore, it is also cost-efficient, with simple fabrication methodology, and demonstrates high sample collection efficiency. All of these benefits ensure that this GNRs-PLLA substrate is a really perfect choice for a variety of SERS applications.
我们报道了一种新型的基于纸张的表面增强拉曼散射（SERS）基底平台，它由吸附有等离子体纳米结构的聚（L-乳酸）（PLLA）纳米纤维纸构成，能够规避现有SERS基底的诸多挑战。这种PLLA纳米纤维纸具有三维多孔结构、极其洁净的表面且疏水性良好（接触角高达133.4°），在拉曼激光激发下背景干扰可忽略不计。由于PLLA纳米纤维与十六烷基三甲基溴化铵（CTAB）分子之间存在强静电相互作用，涂覆有CTAB的金纳米棒（GNRs）能有效地固定在纤维上。这种具有局部亲水性SERS活性区域的疏水纸张基底可以限制分析物分子并防止分子随机扩散。这种限制导致聚焦效应，并且发现GNRs-PLLA SERS基底具有高灵敏度（对罗丹明6G和孔雀石绿为0.1 nM），展现出优异的重现性（相对标准偏差（RSD）约为8%）和长期稳定性。此外，它还具有成本效益，制造方法简单，并且显示出高样品收集效率。所有这些优点确保了这种GNRs-PLLA基底对于各种SERS应用来说是一个非常完美的选择。
