Study of binding of biological molecules to substrate using surface-enhanced Raman (SERS) and surface enhanced infrared spectroscopy (SEIRS)
The goal of the proposed project is to find adequate substrates for detection and identification of the target molecules at the very low concentration found in body liquids (creatinine, paracetamol, …) with the application of surface-enhanced Raman spectroscopy (SERS) infrared spectroscopy (SEIRS). Modern analytical methods in biotechnology and biomedicine must permit detection of substances at very low concentrations in a complex environment. These substances are in general very important for an organism’s health or metabolism. Therefore is the development of nondestructive analytical techniques important challenge in modern analytical biochemistry. The method of choice is surface-enhanced Raman spectroscopy (SERS) which takes advantage of enormous strengthening of the vibrational band due to still not completely understood interaction between the probed molecule and substrate made of modified gold or silver nanoparticles. The method was successfully applied in several studies of samples at a very low concentration such as DNA bases or markers of potentially dangerous bacteria (see for example: Kara S.A. et.al, RSC Advances 6 (2016) 93649-93659) In general is the intensity of vibrational band in classical Raman experiment less thean million times weaker with respect to the initial power of laser beam. However, if we spread the sample on a properly selected and prepared substrate, this intensity may be enhanced up to ten thousand times. And this is the effect which can be used for detection of trace samples in the complex mixtures. The prerequisite factor of the successful experiment is a properly selected substrate, which will be able to selectively bond the molecules of interest. Thus only those molecules which are bonded to the substrate will have enhanced intensity. The goal of the present proposal is to develop a new type of selective substrates on the basis of silicone nanotubes coated with calcium and siloxanes which will selectively attract and bond to selected amino acids, peptide, and proteins. By changes the pH values we will optimize the bonding between the selected peptides and Ca-O-Si-O-R groups from the substrate via complexation of the ionized carboxylic groups present in amino acids, peptides, and proteins.