Coralyne tespiti için kolorimetrik gümüş nanoparçacık problarının geliştirilmesi

Silver nanoparticles (AgNPs) possess unique photochemical, optical and physical properties with superior localized surface plasmon resonance (LSPR) in the visible range. Consequently, the development of biosensors based on silver nanoparticles emerged in various fields in the last two decades, including medical, food and health care industries. Colorimetric detection platforms based especially on the aggregation of AgNPs have drawn great interest due to their simplicity, ease of synthesis and low cost. Likewise, the fluorometric detection platforms based on AgNPs, have emerged as useful tools, mostly due to their higher sensitivity. In this thesis, two different platforms based on AgNPs for the detection of coralyne (COR) were developed. COR is a planar alkaloid with proven anti-proliferative activity in several cell lines and its detection using a simple, low cost technique is desired for its further utilization. The first platform was a colorimetric biosensor based on the LSPR of the AgNPs in the presence of COR and NaCl. First, the AgNPs and their aggregation behavior upon addition of COR were characterized by High Resolution Transmission Electron Microscopy (HRTEM), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and Zeta potential experiments. The optimal salt concentration, pH, temperature and time for the detection platform were determined by monitoring the change in SPR (A612/A400) using UV-Vis spectroscopy, and the lower limit of detection (LOD) was determined as 8.54 nM under the optimized conditions. Real sample experiments were also conducted for measuring the applicability of the probe in complex matrices. The second platform developed was a fluorometric probe based on dT32 modified AgNPs in the presence of coumarin (COU). dT32 modified AgNPs were also characterized by using HRTEM, FTIR, DLS and Zeta potential experiments. LOD was determined to be as 5.24 nM under the optimized dT32 concentration, temperature and time. The developed colorimetric and the fluorometric probes were also tested in urine as real sample via spiking experiments, and the overall recovery percentages were found to be between 92.32%-116.0% and 87%-105%, respectively.