Nanoparticle-based surface-enhanced Raman spectroscopy as an efficient technique to diagnose prostate cancer using blood samples

The application of proteomics to human bodily fluids has increased significantly in recent years. The quest for biomarkers capable of indicating the presence of disease, particularly cancer, directly from the analysis of blood or other fluids such as the saliva, tears or urine is an ongoing concern. The main challenge to be addressed is to provide a rapid and cost effective method for specific in vitro diagnostics. In this context, blood plasma/serum remains potentially the most valuable alternative to identify reliable biomarkers for diagnostic purposes. Raman spectroscopy has become an attractive analytical spectroscopic tool for aqueous system analysis due to the extremely weak light scattering by water molecules. Raman spectroscopy can also detect the changes in the biological macro molecules occurring at the molecular level. Since biochemical changes occur earlier than the morphological changes, the technique can possibly be useful for the early diagnosis of diseases. In particular, Surface Enhanced Raman spectroscopy (SERS) employs gold and silver based nanomaterials to improve the sensitivity of Raman scattering and thus being able to go to trace detection levels. The major aim of this project is to develop a SERS-based approach for convenient and early diagnosis of prostate cancer by using centrifugally filtered blood serum samples. This proposed work will include optimization of the protocols for the preparation of different nanoparticles (NPs), such as gold, silver and iron oxide NPs, which will be immobilised on surfaces or used in solution for the enhancement of Raman signal to enhance the sensitivity of the technique. This surface enhancement of the Raman signal can consequently increase the sensitivity of the technique for the detection of the cancerous changes in the blood serum. Moreover, the optimization of the centrifugal filtration technique for the elimination of large-size proteins will concentrate the low-molecular-weight fraction (LMWF) serum proteins, which might be associated with the development of the disease and hence detectable compared to large-size proteins. This will be followed by SERS of concentrated serum samples of the healthy as well as cancer patients in order to identify biochemical changes associated with the development of the prostate cancer. The Raman spectral data will be analyzed by chemometric methods including Principal Component Analysis (PCA) and Principal Component and Factorial Discriminant Analysis (PCA-FDA). The proposed work shall have a great impact on a better monitoring and care of the prostate cancer patients. It will also open a channel of useful research collaboration between academia, medical institutes and hospitals in the Kingdom