Luo Yinglin, Xing Lida, Hu Chuanshuang, Zhang Weiwei, Lin Xiuyi, Gu Jin
College of Materials and Energy, South China Agricultural University, Guangzhou 510642, PR China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, PR China.
Int J Biol Macromol. 2022 Apr 30;205:366-375. doi: 10.1016/j.ijbiomac.2022.02.102. Epub 2022 Feb 19.
Semiconductor metal-oxide/metal heterostructures with synergetic properties have potential applications in photocatalysis and optical sensors. Here, CuO sub-micro cubes were synthesized under environmentally benign conditions using 2, 2, 6, 6-tetramethylpyperdine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils as a reducing and stabilizing agent. Then the surface of the CuO cubes was decorated with silver nanoparticles (AgNPs) by a substitution reaction. The CuO/Ag heterostructures within the cellulose nanofibrils (CNFs) network were employed as a promising surface-enhanced Raman scattering (SERS) assay for efficient sensing of methylene blue (MB), reaching a maximum enhancement factor (EF) of 4.0 × 10. Their SERS intensities depended on the coverage density of AgNPs and the wavelength of the excitation laser. The excellent SERS performance may result from the charge transfer between Ag and CuO molecules and the strong electromagnetic field at the interface. The CNF-CuO/Ag substrates were capable of detecting MB dye down to 10 M level with a relative standard deviation of 10-15%, demonstrating great sensitivity and reproducibility.
具有协同特性的半导体金属氧化物/金属异质结构在光催化和光学传感器方面具有潜在应用。在此，使用2,2,6,6-四甲基哌啶-1-氧基（TEMPO）氧化的纤维素纳米纤维作为还原剂和稳定剂，在环境友好的条件下合成了CuO亚微米立方体。然后通过取代反应在CuO立方体表面装饰银纳米颗粒（AgNP）。纤维素纳米纤维（CNF）网络中的CuO/Ag异质结构被用作一种有前景的表面增强拉曼散射（SERS）检测方法，用于高效检测亚甲基蓝（MB），最大增强因子（EF）达到4.0×10。它们的SERS强度取决于AgNP的覆盖密度和激发激光的波长。优异的SERS性能可能源于Ag与CuO分子之间的电荷转移以及界面处的强电磁场。CNF-CuO/Ag基底能够检测低至10 M水平的MB染料，相对标准偏差为10-15%，显示出极高的灵敏度和重现性。
