Bull serum albumin coated Au@Agnanorods as SERS probes for ultrasensitive osteosarcoma cell detection

•BSA encapsulated Raman nanoparticles have shown to obtain more stable size and Raman intensity in high-salt bioassay buffers.•The carboxylic acid group of BSA can be easily activated for further biomolecule conjugation such as antibody or nuclear acid.•Here, we designed a novel ultrasensitive and biocompatible SERS nanotag for in vitro detection of Osteosarcoma cells.•This novel Au@AgNRs@BSA can be successfully applied for ultrasensitive detection of Osteosarcoma cells by SERS.

Surface-Enhanced Raman scattering (SERS) has been widely used for imaging and sensing. However, limited reports are currently available on SERS-based cancer cell targeting strategy due to the challenge of synthesizing highly sensitive, reproducible and biocompatible SERS probe. Herein, we developed novel SERS probes, based on BSA (Bull Serum Albumin) coated gold–silver core–shell nanorods modified with Raman reporter 5,5-dithiobis 2-nitrobenzoic acid (DTNB) (Au@AgNRs@BSA@Anti-MICA), for in vitro cancer cell detection. Our results demonstrate that the SERS probe is very robust for cancer cell ultrasensitive detection with good biocompatibility and strong SERS signal.