The proposed research will complete the fundamental study of SERS enhancement in dimers, trimers and other nanoparticle oligomers on plasmonic substrates. However, the bulk of this research is about improvement in SERS immunoassay detection of cancer and TB biomarkers, achievable with systematic reduction in undesirable non-specific protein adsorption during the assay. The SERS is an increasingly active research field spotlighted by about 15000 publications at least as demonstrated by the Scopus.com search result for years 2000- 2016. There are numerous advantages of SERS as a very sensitive, label free, humidity independent and rapid method with great capability of multiplexing due to relatively narrow Raman peaks if compared to fluorescence or UV-vis spectroscopy. One of the most versatile and perspective applications of SERS is in sandwich immunoassays, which provide high sensitivity and low Limit of Detection (LOD) for a detection of a variety of biotargets from tuberculosis to cancer biomarkers. Typically, SERS sandwich assays are conducted on gold film modified with SAM of DSP, DSU or other linker with succinimidyl group that binds to capture proteins (e.g. a-hIgG).[1]
The direction of the future work looking beyond the 3-year time span of this project is road from single SERS assay biomarker detection towards multiplexed SERS detection of several cancer biomarkers simultaneously. As soon as we make work the detection of breast and lung cancer biomarkers we are planning to proceed with detection of biomarkers of ovarian cancer (e.g. CA-125, etc) and bladder cancer ( fibrin, fibrinogen, etc), which is typically done by analysis of blood or urine. Those plans are also can be scheduled for 2021, just after completion of this project. Muliplexing in biomarker detection should significantly decrease assay time and cost per each analyte. Sensitive multiplexed assays will increase reliability in the cancer ( and pathogens) diagnostics, saving many lives. It will save time and money providing doctors with better information for the choice of individual treatment procedure, making a significant step towards personalized medicine, which is named among perspective goals of Kazakhstan development.
Sandwich SERS assay is highly sensitive method with a strong potential to save many lives, if it will be applied for early diagnostics of cancer. Often it is important to be able to detect biomarkers at very low concentration, because concentration of cancer biomarker in blood increases while cancer tumor grows and the survival rate usually decreases exponentially in this process.