Raman spectroscopy though a very powerful tool is a very weak phenomenon. Nanostructures made from plasmonic metals like Gold, Silver or Copper, provide an enhanced electric field in their vicinity when excited by an electric field by the phenomenon of LSPR. Biomolecules are relatively weak Raman scatterers and their spectra get highly enhanced in the presence of plasmonic nanostructures. Aurora Kinase enzymes are related to tumorigenesis and are potential anti-cancer drugs. The orientation of the enzyme on the surface of the silver nanoparticles results in different Raman spectra. We discovered Felodipine as an allosteric and a specific inhibitor for the oncogenic Aurora Kinase A by analysing the SERS spectrum of the Aurora Kinase A itself and in the presence of the molecule. (PNAS 2014, 111, 10416-10421)
Extracellular vesicles (EVs) laden with lipids, proteins, DNA, and micro-RNAs play important biological functions in intercellular communication and have pivotal roles in pathophysiological conditions. We reported a simple citrate reduced silver nanoparticles assisted surface-enhanced Raman spectroscopy (SERS) as a tool to distinguish EVs extracted from several cell lines like HeLa, HeK293 and Atg5−/− isolated under autophagic conditions (nitrogen starvation). Our study helped in the facile detection and differentiation of EVs isolated between two closely related human cell lines that differ by their autophagic ability. The principal component analysis (PCA) of the SERS spectra of these EVs consistently showed the presence of distinct chemical compositions of the EVs. (JPCB, 2020, 124, 10952-10960)
HIV-I is classified into 9 distinct and primary genetic subtypes designated A through J (with the exception of E and I which are recombinants). Distribution of the viral subtypes across the globe is non-uniform. Capture probes for capturing nucleic acids were invented to develop a high sensitivity assay for molecular typing of a biological sample using surface-enhanced Raman scattering (SERS) including resonance scattering (SERRS). Detector probes were designed to detect the capture probes, along with a kit for molecular typing of biological sample using SERS. Through this assay we were able to detect HIV RNA and also differentiate their various subtypes. (South Africa (No. 2009/03128), USA (No. 8,227,590))
