Advanced NIR SERS Active Nanoprobes Toward In Vivo Multiplex Detection

Y-S Lee
Seoul National University, KR

Keywords: SERS (surface-enhanced Raman scattering), near-IR, in vivo multiplex detection

Summary:

To effectively apply the SERS probes to in vivo detection, they need to produce strong signals within a NIR region of 700–900 nm; the so-called biological window. NIR SERS dots consisted of plasmonic Au/Ag HS (hollow-shell) assemblies on the surface of silica nanospheres,5 whose plasmonic structures were adjusted toward the NIR excitation laser wavelength (785 nm). We detected the NIR SERS dots at concentrations as low as a single particle (average SERS EF value = 2.8 × 105). Furthermore, the NIR SERS dots also demonstrated a high reproducibility due to the large number of SERS-active sites on a single silica nanosphere. The signals from the NIR SERS dots were effectively detectable even with an injection depth of just 8 mm in porcine tissues, as shown in Fig 1. Finally, three kinds of NIR SERS dots (4-BBT, 4-CBT, and 4-FBT coded NIR SERS dots), along with a mixture of the three, were applied to in vivo multiplex detection in a mouse. The mixture of NIR SERS dots produced strong individual SERS signals from deep tissues without spectral overlap, and it also proved very easy to deconvolute the mixed signals from the three different NIR SERS dots.