On 31 May 2024 a PhD student of the Institute of Materials Science Nadzeya Khinevich has defended her doctoral dissertation entitled “Two-dimensional structures of nanoparticles for elements of surface-enhanced Raman scattering substrates ” and gained a doctor degree in the field of science of Physics. Scientific supervisor Prof. Habil. Dr. Sigitas Tamulevičius.
The dissertation explores the application of surface-enhanced Raman scattering spectroscopy (SERS) in various fields, highlighting its potential in biosensing. Despite significant advances in the fields of nanomaterials and plasmonics, the practical use of SERS remains a challenge due to the lack of inexpensive, reproducible, and highly efficient substrates. This research aims to address these gaps by exploring metallized porous silicon (PS) structures and periodic nanoparticle (NP) arrays to improve SERS sensitivity.
The research focuses on synthesizing chemically homogeneous silver nanoparticles (AgNPs) and studying their ultrafast optomechanical properties. In addition, the fabrication of irregular and regular SERS-active substrates using capillary particle deposition is investigated and their sensitivity is assessed using organosulfur compounds as target molecules.
Key results include optimal conditions for the synthesis of monodisperse AgNPs, investigation of ultrafast relaxation of charge carriers in AgNPs, and development of PS structures as templates for AgNP arrays. Additionally, the study demonstrates wavelength-tailored SERS substrates with enhanced sensitivity achieved by tuning the plasmon resonance to the excitation laser wavelength and creating hot spots in periodic NP arrays.
The thesis contributes to the field by proposing new approaches to improve SERS sensitivity, paving the way for practical applications in biosensing.
The research was carried out at the Institute of Materials Science of KTU and during the internship in Mads Clausen Institute at University of Southern Denmark.
