Bio-Inspired Materials Research Laboratory (BIMREL), Department of Chemistry, Gazi University , 06500 Ankara, Turkey.
Department of Bioengineering, Faculty of Engineering and Architecture, Sinop University , 57000 Sinop, Turkey.
ACS Appl Mater Interfaces. 2017 May 31;9(21):18199-18206. doi: 10.1021/acsami.7b03042. Epub 2017 May 16.
The design and development of three-dimensional (3D) nanostructures with high surface-enhanced Raman scattering (SERS) performances have attracted considerable attention in the fields of chemistry, biology, and materials science. Nevertheless, electrospraying of organic small molecules on low-cost flexible substrates has never been studied to realize large-scale SERS-active platforms. Here, we report the facile, efficient, and low-cost fabrication of stable and reproducible Au-coated electrosprayed organic semiconductor films (Au@BDY-4T-BDY) on flexible regular aluminum foil at a large scale (5 cm × 5 cm) for practical SERS and catalytic applications. To this end, a well-designed acceptor-donor-acceptor-type solution-processable molecular semiconductor, BDY-4T-BDY, developed by our group, is used because of its advantageous structural and electrical properties. The morphology of the electrosprayed organic film changes by solution concentration, and two different 3D morphologies with out-of-plane features are obtained. Highly uniform dendritic nanoribbons with sharp needle-like tips and vertically oriented nanoplates (∼50 nm thickness) are achieved when electrospraying solution concentrations of 240 and 253% w/v (mg/mL) are, respectively, used. When these electrosprayed organic films are coated with a nanoscopic thin (30 nm) Au layer, the resulting Au@BDY-4T-BDY platforms demonstrate remarkable SERS enhancement factors up to 1.7 × 10 with excellent Raman signal reproducibility (relative standard deviation ≤ 0.13) for methylene blue over the entire film. Finally, Au@BDY-4T-BDY films showed good catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with rate constants of 1.3 × 10 and 9.2 × 10 min. Our results suggest that electrospraying of rationally designed organic semiconductor molecules on flexible substrates holds great promise to enable low-cost, solution-processed, SERS-active platforms.
具有高表面增强拉曼散射（SERS）性能的三维（3D）纳米结构的设计和开发在化学、生物学和材料科学领域引起了相当大的关注。然而，将有机小分子电喷雾到低成本柔性衬底上以实现大规模 SERS 活性平台的研究从未有过。在这里，我们报告了在大规模（5 cm × 5 cm）上在柔性常规铝箔上制造稳定且可重复的涂金电喷雾有机半导体薄膜（Au@BDY-4T-BDY）的简便、高效和低成本方法，用于实际的 SERS 和催化应用。为此，使用了我们小组开发的具有有利结构和电学性质的受主-给体-受体型溶液处理分子半导体 BDY-4T-BDY。电喷雾有机膜的形态通过溶液浓度而变化，并且获得了两种具有非平面特征的不同 3D 形态。当分别使用 240 和 253% w/v（mg/mL）的电喷雾溶液浓度时，可以获得具有尖锐针状尖端的高度均匀的树枝状纳米带和垂直取向的纳米板（约 50 nm 厚）。当将这些电喷雾有机膜涂覆有纳米级薄（30 nm）金层时，所得的 Au@BDY-4T-BDY 平台表现出高达 1.7×10 的显著 SERS 增强因子，并且整个膜上的亚甲蓝的拉曼信号重现性非常好（相对标准偏差≤0.13）。最后，Au@BDY-4T-BDY 薄膜显示出对 4-硝基苯酚还原为 4-氨基酚的良好催化活性，速率常数分别为 1.3×10 和 9.2×10 min。我们的结果表明，在柔性衬底上电喷雾合理设计的有机半导体分子具有很大的应用前景，可以实现低成本、溶液处理的 SERS 活性平台。
