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Vibrational spectroscopy is proved to be a reliable technique for biological tissue analysis and screening of pathological differences between healthy and cancerous tissues. Due to the ubiquity and inherent complexity of cancerous diseases together with existing challenges in diagnostic methods, the search for reliable separation of cancerous and healthy tissues is of great importance. In our previous works, we have shown that spectral differences between cancerous and healthy tissues of kidney can be found using FTIR–ATR and surface enhanced Raman scattering (SERS) spectroscopy. SERS allows identification and detection of molecules at low concentration and oversteps sensitivity limits of ordinary spectroscopic methods, thus is available for identification of cancerous tissues in cases where FTIR – ATR technique is not sensitive enough. For remote diagnostic applications (for example during surgeries) experimental configurations employing optical fibers are indispensable. In this work, we investigated the technical aspects of using optical fibers to accomplish SERS of biological tissues. For this purpose, we used commonly available optical fiber types: fused silica and acrylic glass (PMMA). One end of the fiber was coated with Ag nanoparticles. Different coating techniques were applied, such as formation of a self-assembled monolayer of the nanoparticles or drying of colloidal nanoparticle suspensions. Fiber-based SERS spectra of cancerous and healthy kidney tissues were analyzed. We found that reasonable quality fiberbased SERS spectra of normal and cancerous kidney tissue can be obtained through silica fiber with SERS activated tip. Furthermore, a distinction between cancerous and healthy kidney tissues from SERS spectra is found as cancerous kidney tissues contain spectral bands of glycogen which can be used as spectral markers of cancerous cells.
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