Fabrication of long-range ordered, broccoli-like SERS arrays and application in detecting endocrine disrupting chemicals

摘要: Periodic broccoli-shaped Au and Ag surface-enhanced Raman spectroscopy (SERS) arrays were fabricated by combining ordered SiO2 colloidal crystal templates with the physical deposition technique. The crystal-assisted SERS substrates have a long-range, adjustable periodic structure clean surface without incorporating any reductants or surfactant chemicals. Different from depositing directly on flat substrates, nanostructure array has larger effective area under same projected of laser irradiation, which exposes more “hot spots”. An increased roughness also been created as highly bumpy feature morphologies, resulting in greater amplification than conventional metal film over nanosphere (MFON). performances reveal that long-range broccoli-like morphology is promising platform it sensitive, reproducible stable. slightly higher enhancement factor (EF) array, they both are order 107 enhancement. Compared to our previous work, deposited noble nanoparticles onto EF improved one two orders magnitude. Finite-difference time-domain (FDTD) simulation was performed estimate electromagnetic field distribution. Finally, endocrine disrupting chemicals (EDCs) (dioctyl phthalate (DOP) dibutyl (DBP), homologous series) at different concentrations successfully identified detection limits 0.24 × 10−9 M 0.22 M, respectively. This study suggests candidates for chemical sensing this substrate fabrication technique can be accessible standard industrial processes.