Protein detection based on surface enhanced raman scattering on plasmonic nanowells

Qualitative and quantitative analyses of proteins, which are organic macromolecules with various functions in the structure of living things, have an important place today. Surface-enhanced Raman scattering (SERS) technique, which is among the detection methods of biological and chemical molecules, allows the sensitive, fast, and accurate detection of proteins. By utilizing the plasmonic properties of nanomaterials, Raman scattering can be enhanced, and the detection of proteins can be performed even at low concentrations. Within the scope of this thesis, silver nanoparticles (AgNPs) prepared by the chemical reduction method were mixed with latex microparticles of different sizes and deposited on the glass slide surface by the convective assembly method. Nanowells were obtained by washing latex particles with an organic solvent. Nanowell SERS substrates were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The SERS activities of the prepared surfaces were determined using 4-aminothiophenol (4-ATP). According to the results obtained, it was determined that the SERS substrate, consisting of nanowells prepared with 1.0 µm latex particles, had the highest SERS activity. SERS spectra of different concentrations of proteins (Avidin, BSA, Cytochrome-C, Hemoglobin, and Lysozyme) were taken on the YZRS substrate with the highest SERS activity, and the lowest detection limit was determined to be 0.1 µg/mL. The results showed that proteins can be detected down to low concentrations using SERS substrate prepared with a fast, inexpensive, and simple technique.