A novel natural SERS system for crystal violet detection based on graphene oxide wrapped Ag micro-islands substrate fabricated from Lotus leaf as a template

A stable biomimetic surface enhanced Raman scattering (SERS) system was fabricated by covering graphene oxide (GO) on the Ag micro-islands substrate using micro/nanostructured Lotus leaf (L.l.) as a template via the simple magnetron sputtering system and dip-coated method. The Raman signals of crystal violet (CV) on the GO-Ag-L.l.-30 substrate (the sputtering time was 30 min) showed far better SEAS performances than Ag-L.l.-30 hybrids in terms of signal enhancement, sensitivity and stability. The results suggested that the SEAS activity of the bio-inspired GO-Ag-L.l.-30 substrate using CV as probe molecules showed an enhancement factor (EF) of similar to 1.52 x 10(6). Sensitivity tests indicated that the limit of detection (LOD) for CV was as low as 5 x 10(-10) M, which was two orders of magnitude lower than Ag-L.l.-30 substrate. Time-stability for 30 days was also reported which revealed that the Raman intensity of CV on GO-Ag-L.l.-30 substrate only reduced by 18.2% after aging for 30 days. Moreover, the maximum relative standard deviations (RSD) of Raman intensities was less than 7.09%, demonstrating outstanding reproducibility and uniformity of GO-Ag-L.l.-30 substrate. Therefore, the cost-efficient and high-performance SEAS system shows great application prospects in biochemical sensing and attracts broad attention to many other natural materials which can be prepared as multifarious novel SEAS systems.