| The surface patterns with ordered morphology,well-controlled dimension have attracted significant attention.Due to the Surfaces with ordered nanostructures have distinctive and intriguing properties,the nanostructures have promising applications in a number of areas including biological and chemical sensing,surface wettability,surface enhanced Raman scattering（SERS）,antireflection,absorbers,and many others.Although there are many advanced lithographic techniques can be used to construct nanostructures,for instance the nanoimprinting,focused ion beam lithography,photolithography,soft lithography,electron beam lithography and so forth.Among the aforementioned patterning techniques,nanosphere lithography based on colloidal crystals composed of colloidal spheres without complex and expensive equipment was widely utilized for generating periodic nanostructures.Herein,we focus on the construction of nanostructures by the nanosphere lithography integrating with ion etching technology.Through the self-assembly of colloidal spheres and controlling of morphological,the nanostructures provide various patterns and the performance were investigated as following:（1）The low-cost,stabilized and ultrasensitive three-dimensional（3D）hierarchical surface-enhanced Raman scattering substrates（“sunflower-like”nanoarrays decorated with Ag nanoparticles,denoted as SLNAs-Ag）have been obtained by fabricating binary colloidal crystals and then decorating with Ag film.In order to provide a larger density of hot spots within the laser-illumination area,the silica sphere arrays were chosen as the island-type platform for the polystyrene（PS）nanosphere deposition,and the distances between the PS nanospheres were tuned by etching for different durations.Compared with conventional 2D planar systems,the as-fabricated 3D SLNAs-Ag exhibited extremely high SERS sensitivity ascribed to the larger SERS active regions.Quantitative detection of molecules with an extremely low incident laser power was achieved on the“sunflower-like”nanoarrays in which the PS nanospheres were etched for 5 minutes and decorated with Ag film,and the corresponding analytical enhancement factor is calculated to be 2×1014 with the concentration of rhodamine 6G down to 10-15 M.（2）The hollow nanocones combined with microbowls were prepared by the double-layer PS colloidal crystal template synthesized by self-assembly process,then the double-layer PS colloidal crystal were etched by plasma etching.Using the hollow nanocones combined with microbowls nonoarrays as SERS substrates,Raman signals of single viruses are greatly improved.The detection limit of this substrate for R6G reached 10-9 M,and the complete Raman signal of adenovirus could be obtained accurately.（3）The large-area nanostructured omniphobic surfaces textured with re-entrant geometries on silicon substrates were created combining colloidal lithography,thermal evaporation and reactive ion etching.We show that tuning the nanostructure shape and aspect ratio dramatically influences the surface-wetting properties,with proper control crucial for achieving superhydrophobicity with low adhesion.Our resulting superhydrophobic SERS platform demonstrates excellent water repellency with a static contact angle of 156°.Moreover,the ordered micro/nanostructures with reentrant geometry were serve as ideal platforms to enhance detection sensitivity.By combining the analyte concentration effect of superhydrophobic surfaces with the intense electromagnetic‘‘hot spots’’of Au nanobipyramids,our superhydrophobic SERS platform achieves an ultra-low detection limit of 5×10-12 M for R6G using just 10μL of analyte solutions.And the concentration of tranexamic acid decreased to 10-5 M,the Raman signal was still obvious.（4）A single layer PS spherical colloidal crystal template was obtained by self-assembly,and the nanoconical array was prepared by ion beam etching.By changing the size of colloidal spheres and adjusting the ion dose,nanoconical arrays with different structures and different depth-width ratios were obtained.The nanoconical arrays with different morphologies were prepared by changing the Angle between the sample table and the ion beam direction,and the UV-visible absorption spectrum and transmission spectrum of the samples at different doses were analyzed to characterize the anti-reflection performance of the samples.The experimental results show that PS monolayer colloid template as a mask can adjust and control the optical absorption peak of the nanoarrays by ion beam etching,which effectively improves its potential application in optics.The antireflection property in the visible region of our design is significantly enhanced compared to glass slide,and the transmittance in visible region was increased from 90.6%to 97.8%. |
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