Using a ferrocenylsilane-based block copolymer as a template to produce nanotextured Ag surfaces: uniformly enhanced surface enhanced Raman scattering active substrates

We report a method of fabricating nanotextured Ag surfaces using a template of self-assembled inorganic-containing block copolymer, polystyrene-b-polyferrocenylsilane. The Ag surfaces with periodically ordered nanoscale features created by the self-organized block copolymer are capable of producing enhanced Raman signals. Using benzenethiol as a probe molecule, an enhancement factor of up to 106 has been observed. More importantly, the enhancement is very uniform; less than 10% Raman signal variation has been obtained. Furthermore, since the size and spacing of the nanostructures can be adjusted by tailoring the polymer chain length, the electromagnetic field can potentially be tuned to achieve even higher surface-enhanced Raman scattering (SERS) activity. This inorganic-containing block copolymer template approach not only provides a simple and straightforward method to fabricate SERS active substrates but also offers a means to experimentally examine the SERS mechanism.