Department of Materials Engineering, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018, PR China.
Department of Materials Engineering, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018, PR China; Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Zhejiang Sci-Tech University, Ministry of Education, Hangzhou 310018, PR China.
Biosens Bioelectron. 2014 Apr 15;54:91-101. doi: 10.1016/j.bios.2013.10.047. Epub 2013 Oct 31.
We have demonstrated a facile approach for the fabrication of flexible and reliable sulfydryl functionalized PVA/PEI nanofibers with excellent water stability for the self-assembly of Au nanocrystals, such as Au nanoparticles (AuNPs), Au nanoflowers (AuNFs) and Au nanorods (AuNRs), used as the highly efficient surface-enhanced Raman scattering (SERS) substrates for the detection of rhodamine B (RhB). Various methods were employed to cross-link the PVA nanofibers with better morphology and porous structures after immersing in water for desired times. Various SERS-active Au nanocrystals, such as AuNPs, AuNFs, and AuNRs have been successfully synthesized. After the grafting of MPTES on the cross-linked PVA/PEI nanofibers, the Au nanocrystals can easily be self-assembled on the surfaces of the nanofibers because of the strong interactions of the Au-S chemical bondings. The Au nanocrystals self-assembled throughout the PVA/PEI nanofibers used as SERS substrates all exhibit enhanced SERS signals of RhB compared with their individual nanocrystals. It is mainly due to the close interparticle distance, mutual orientation and high density of "hot" spots, that can strongly affect the overall optical response and the SERS enhancement. By changing the amounts of the self-assembled AuNFs on the nanofibers, we can control the density of the "hot" spots. With the increased amounts of the AuNFs throughout the nanofibers, the SERS substrates show enhanced Raman signals of the RhB, indicating that the increased density of "hot" spots can directly lead to the SERS enhancement. The AuNFs/(PVA/PEI) SERS substrates show good sensitivity, reliability and low detection limit (10(-9) M). The presented approach can be broadly applicable to the assembly of different types of plasmonic nanostructures and these novel materials with strong SERS enhancement can be applied in bioanalysis and biosensors.
我们已经展示了一种简便的方法，用于制造具有优异的水稳定性的灵活可靠的巯基功能化 PVA/PEI 纳米纤维，可用于自组装金纳米晶体，例如金纳米颗粒 (AuNPs)、金纳米花 (AuNFs) 和金纳米棒 (AuNRs)，用作高灵敏度的表面增强拉曼散射 (SERS) 基底，用于检测罗丹明 B (RhB)。使用各种方法在水中浸泡所需时间后交联具有更好形态和多孔结构的 PVA 纳米纤维。成功合成了各种 SERS 活性金纳米晶体，例如 AuNPs、AuNFs 和 AuNRs。在交联的 PVA/PEI 纳米纤维上接枝 MPTES 后，由于 Au-S 化学键的强相互作用，金纳米晶体可以容易地自组装在纳米纤维的表面上。用作 SERS 基底的金纳米晶体自组装整个 PVA/PEI 纳米纤维都表现出与单个纳米晶体相比增强的 RhB 的 SERS 信号。这主要是由于紧密的粒子间距离、相互取向和高密度的“热点”，可以强烈影响整体光学响应和 SERS 增强。通过改变自组装的 AuNFs 在纳米纤维上的量，我们可以控制“热点”的密度。随着纳米纤维中 AuNFs 的量的增加，SERS 基底显示出 RhB 的增强拉曼信号，表明“热点”密度的增加可以直接导致 SERS 增强。AuNFs/(PVA/PEI) SERS 基底具有良好的灵敏度、可靠性和低检测限（10(-9) M）。所提出的方法可以广泛应用于不同类型的等离子体纳米结构的组装，并且这些具有强 SERS 增强的新型材料可以应用于生物分析和生物传感器。
