Au/SiO2-Nanolaminated plasmonic nanoantennas as refractive-index-insensitive and transparent surface-enhanced raman spectroscopy substrates
Wonil Nam, Junyeob Song, Seied Ali Safiabadi Tali, Henri Lezec, Amit Agrawal, Wei Zhou
Surface-enhanced Raman spectroscopy (SERS) has become a powerful technique for ultrasensitive biochemical detection providing molecular fingerprint information. Due to the strong dependence of surface plasmon resonance wavelength on plasmonic nanostructures' surrounding refractive index (RI), SERS enhancement factors (EFs) at hotspots are sensitive to changes in background RI, which is detrimental to quantitative SERS biochemical analysis in many real-world applications with spatially and temporally varying RI matrices. Here, we report on a tapered-shape nanolaminate plasmonic nanoantenna (TNLNA) platform that supports multiple, spatially overlapped, hybridized magneto- electric localized surface plasmon modes possessing high SERS EFs (>107) and an insensitivity to background RI variations (between 1.30 and 1.60). Furthermore, we demonstrate that uniform arrays of TNLNAs can be manufactured on flexible transparent polymer substrates to achieve backside-excitable SERS measurements for in-situ label-free glucose monitoring on a skin phantom.
, Song, J.
, Safiabadi Tali, S.
, Lezec, H.
, Agrawal, A.
and Zhou, W.
Au/SiO2-Nanolaminated plasmonic nanoantennas as refractive-index-insensitive and transparent surface-enhanced raman spectroscopy substrates, ACS Applied Nano Materials, [online], https://doi.org/10.1021/acsanm.1c00389
(Accessed December 6, 2023)