Objective: 

Surface-enhanced Raman scattering (SERS) is powerful spectroscopic technique which is routinely used for material characterization. The technique has advanced to a point where it can now be used in medicine for clinical decision making as well. Its power can be attributed to its fingerprinting property, low sensitivity to water, minimum sample preparation step and increased sensitivity with the recent developments in instrumentation. In this study, we demonstrate the capability of SERS for tissue differentiation for clinical applications.

Methods: 

Tissue samples obtained from model animals and human subjects were quickly frozen by submerging in liquid nitrogen and crashed to homogenize. Then, these samples were mixed with concentrated colloidal silver nanoparticles (AgNPs). A 2 mL of this mixture was spotted on CaF2 substrate and let it dry at room temperature. The SERS spectra were acquired from a Raman spectrometer (Renishaw InVia Flex, England) equipped with an 830 nm laser. The spectra obtained from tissues were comparatively evaluated to distinguish their disease status.

Results: 

First, tissue samples from several different rat organs such as brain, kidney and heart were analyzed. It was found that the technique can provide valuable molecular level information about the physiological function of the organ. Second, the tissue and tumor samples from patients undergoing brain surgery were evaluated for possible differentiation without going through conventional diagnosis methods. It was again found that the technique can identify the healthy tissue and tumor, even the peripheral tissue surrounding the tumor.

Conclusions: 

In this study, we first time in literature demonstrated the applicability of SERS for tissue differentiation. Further, brain tumors and tissue surrounding the tumor through the healthy tissue can be identified quickly. This suggests that the technique can be used as decision making tool even during the surgery without going through lengthy procedures.