Nano enabled Surface Enhanced Raman Spectroscopy for the detection classification and grading of tumor tissues

Abstract

Prevalence of increasing cancer patients always demands for the development of simple, rapid and accurate diagnosis methods. Even though several advanced imaging modalities exists, histopathology is considered as the gold standard for understanding detailed information about the abnormal or neoplastic changes. Morphological features of cells and other components in the tissues are stained and disease specific structural characteristics are used to interpret and classify stages of neoplastic changes, but require sufficient time and skilled persons, like pathologist. In this thesis, the study outlines on developing a method based on nanotechnology assisted, enhanced Raman scattering phenomena for cancer detection, classification and grading. Raman spectroscopic fingerprints of the tissues can reveal its biochemical composition; constituted by several bio molecules are identified by their vibrational energy levels of chemical bonds. Whenever a malignant transformation occurs, there will be a corresponding change in their biochemical signatures constituted by molecular level changes. Several studies have been reported on Raman approach for cancer detection, but its clinical utility is often impeded by the low Raman scattering efficiency and high fluorescence from the tissues. Here, we have utilized a novel surface-enhanced Raman scattering (SERS) substrate that can enhance the Raman scattering features of tissues. We hypothesize that the enhanced spectral features acquired from SERS substrates can improve the accuracy of cancer detection and classification. The first study focuses on the development of large area Ag-TiO2 SERS active nanostructures that can be used as substrates to enhance Raman signature of tissues. A two-step process involving hydrothermal synthesis of TiO2 nanostructures on Ti plate followed sputtering deposition of Ag nanoparticles were used for our SERS substrate development. ..