Cu0(core)-Au0(shell) (Cu@Au) bimetallic nanoparticles (NPs) synthesized under microwave-assisted heating were interrogated for surface enhanced Raman scattering (SERS)-active substrates. NPs characterization, by XRD, XPS and UV/vis spectroscopy, showed the formation of self-assembled particles with the occurrence of electron transfer from Cu to Au and the absence of CuxO. TEM and AF4 demonstrated NPs with a mean diameter of 4.7 nm. Despite the low LSPR shown by small nanoparticles (<10 nm diameter), our Cu@Au NPs showed enhanced SERS effect, demonstrated by the calculated scattering signal enhancement factor (3 × 105), which may be related to electromagnetic coupling. Selected examples of analytes of interest, including some biomolecules, were studied to demonstrate the versatility of our Cu@Au NPs as SERS-active substrates.
Cabello, G., Nwoko, K. C., Marco, J. F., Sánchez-Arenillas, M., Méndez-Torres, A. M., Feldmann, J., … Smith, T. A. D. (2019). Cu@Au self-assembled nanoparticles as SERS-active substrates for (bio)molecular sensing. Journal of Alloys and Compounds, 791, 184–192. https://doi.org/10.1016/j.jallcom.2019.03.279