title: Hierarchical nanogaps within bioscaffold arrays as a high-performance SERS substrate for animal virus biosensing.
abstract: A three-dimensional (3D) biomimetic SERS substrate with hierarchical nanogaps was formed on the bioscaffold arrays of cicada wings by one-step and reagents-free ion-sputtering techniques. This approach requires a minimal fabrication effort and cost and offers Ag nanoislands and Ag nanoflowers with four types of nanogaps (<10 nm) on the chitin nanopillars to generate a high density of hotspots (∼2000/μm2). The 3D biomimetic substrate shows a low detection limit to Rhodamine 6G (10(-13) M), high average enhancement factor (EF, 5.8×10(7)), excellent signal uniformity (5.4%), good stability, and suitability in biosensing. Furthermore, the finite-difference time-domain (FDTD) electric-field-distribution simulations illustrate that the 3D biomimetic SERS substrate provides the high-density hotspot area within a detection volumem, resulting in enormous SERS enhancement. In addition, the conspicuous far-field plasmon resonance peaks were not found to be a strong requirement for a high EF in 3D biomimetic substrates. Additionally, the novel substrate was applied in label-free animal viruses detection and differentiation with small amounts (1.0 μL) and low concentrations of analyte (1×10(3) PFU/mL), and it exhibited potential as an effective SERS platform for virus detection and sensing.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University , Wuhan 430070, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Shao
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Lu
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.forename: Heyou
authors.initials: H
authors.lastname: Han
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.forename: Wentao
authors.initials: W
authors.lastname: Li
authors.forename: Qigai
authors.initials: Q
authors.lastname: He
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.forename: Juanni
authors.initials: J
authors.lastname: Chen
mesh_terms: D032701:Biomimetics; D015374:Biosensing Techniques; D057230:Limit of Detection; D015203:Reproducibility of Results; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014780:Viruses / Q000302:isolation & purification*