A Bioinspired Ag Nanoparticle/PPy Nanobowl/TiO₂ Micropyramid SERS Substrate

Abstract

In this paper, the micropyramid structure was transferred to the TiO2 substrate by soft imprinting. Then, the PPy nanobowls were assembled onto the surface of the TiO2 micropyramids through the induction of the PS template. Finally, a layer of Ag nanoparticles was deposited on the surface of PPy nanobowls to form a novel Ag nanoparticle/PPy nanobowl/TiO2 micropyramid SERS substrate. Its structure is similar to the bioinspired compound eyes. This substrate exhibited excellent antireflection, ultra-sensitivity, excellent uniformity, and recyclability. The concentration of R6G molecules can be detected as low as 10−9 mol/L, and the Raman enhancement factor can reach 3.4 × 105. In addition, the excellent catalytic degradation performance of the substrate ensures recyclability. This work proves that the micropyramid structure can be applied to other SERS materials besides silicon by the above methods, which broadens the selection range of composite SERS materials.

Keywords

• TiO₂ micropyramid
• PPy nanobowl
• SERS
• soft imprinting
• bioinspired