A Comparative Study of the Effectiveness and Limitations of Three Different Substrates for Surface-Enhanced Raman Scattering

J. Kim, S. Lee, H-K Park
Kyung Hee University,
Korea

Keywords: Raman spectroscopy, surface-enhanced Raman scattering, nanoparticles, diagnosis

Summary:

Surface-enhanced Raman scattering (SERS) has been widely used as a representative technique for analysis and quantification of specific biological and chemical molecules. SERS is a phenomenon in which the intensity of light scattered from the molecule is amplified when light is shone on the molecules placed on nanostructured metallic surface. Various strategies have been reported for fabricating nanostructured metallic platforms for efficient SERS substrates. However, these SERS substrates have several drawbacks such as a complex fabrication process, lack of uniformity at large scale and MEMS incompatibility. There are two approaches proposed by Kim et al. [1] and Park et al. [2] to overcome the above problems. Kim et al. [1] suggested a facile fabrication technique for sensitive SERS detection, which adopts the successive ionic layer absorption and reaction (SILAR) method. The SILAR method led to direct synthesis of AgNPs on the reactive site such that the presence of AgNPs was observed at the exterior and interior of the paper. Another fabrication proposed by Park et al. [2] is less complex and inexpensive. The first step was to induce Au/Ag alloy growth on a bare gold surface. Then, the selective wet etching of Ag using nitric acid produces a porous gold layer on the micro-resonator. Lastly, we considered a commercial SERS substrate called SERStrate (Silmeco, Copenhagen, Denmark) [3] which is expected to be show SERS signal uniformity over large areas and very low background noise. We evaluated using two samples including real HPV-infected human cervical fluid and carcinogenesis associated MG solution to investigate SERS spectra for three different SERS substrates. We discussed the effectiveness and limitations of three different substrates for SERS in terms of a facile, low-cost, high-sensitivity SERS fingerprinting platform. Overall, the study provides useful guidelines towards the choice of suitable methods and strategies based on Surface-enhanced Raman scattering. References [1] Kim et al., Facile Fabrication of a Silver Nanoparticle Immersed, Surface Enhanced Raman Scattering Imposed Paper Platform through Successive Ionic Layer Absorption and Reaction for On-Site Bioassays, ACS Applied Materials & Interfaces, 2015. In press. [2] Park et al., Multimodal label-free detection and discrimination for small molecules using a nanoporous resonator, Nature communications, 2014. doi:10.1038/ncomms4456. [3] SILMECO SERS substrates. http://www.silmeco.com