Implantable "smart tattoo" SERS nanosensors for in vivo detection of nucleic acid biotargets in a large animal model
Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo molecular detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo detection of nucleic acid targets using a promising type of surface-enhanced Raman scattering (SERS) nanosensor implanted in the skin of a large animal model (pig). The in vivo "smart tattoo" nanosensor used in this study employs the "inverse molecular sentinel" (iMS) detection scheme, which is a label-free homogeneous biosensing system based on a non-enzymatic DNA strand-displacement process and conformational change of stem-loop (hairpin) oligonucleotide probes upon target binding. In this study, plasmonics-active nanostar was utilized as an efficient in vivo SERS sensing platform due to their tunable absorption bands in the near infrared region of the "tissue optical window. The results of this study illustrate the usefulness of SERS iMS nanosensors as an implantable skin-based in vivo biosensing platform, providing a foundation for developments in continuous health status sensing, disease biomarker monitoring, and other clinical translation applications.
