SERS Nanoprobes in Biologically Raman Silent Region for Tumor Cell Imaging and In Vivo Tumor Spectral Detection in Mice

Surface enhanced Raman scattering (SERS) is widely used in biological applications due to its high sensitivity and deep tissue penetration. Most SERS nanoprobes with fluorophore attachments have Raman signals between 1400 and 1700 cm(-1). Here, a series of SERS nanoprobes anchored with alkyne moieties in the biologically Raman-silent region through C-Au bond formation is prepared. To achieve target-specific recognition, two nucleic acid aptamers (AS1411 and MUC1) and two control oligonucleotides (C-con and T-con) with the same alkyne moiety are also attached on the Au surface, respectively. Both aptamer-charged SERS nanoprobes successfully target MCF-7 cells, which could possibly achieve cross-check of target cells and overcome the possible false positive results. And the limit of detection reaches up to five cancer cells, which has great potential in circulating tumor cells detection. Further in vivo studies indicate that both SERS nanoprobes are successfully employed to target tumors in living mice with an obvious signal (approximate to 2205 cm(-1)) at the Raman silent region after tail intravenous injection for the first time.