Preparation of magbetic nanoplatforms basen on surface enhanced raman spectroscopy for selective detection of Malachite green

ABSTRACT PREPARATION OF MAGBETIC NANOPLATFORMS BASEN ON SURFACE ENHANCED RAMAN SPECTROSCOPY FOR SELECTIVE DETECTION OF MALACHITE GREEN EKMEN, Elvan M. Sc. Thesis, Chemistry Engineering Department Supervisor: Assoc. Prof. Dr. Adem ZENGİN June 2019, 63 pages In this study, magnetic nanoparticles was prepared for detection of malachite green. For this purpose, magnetic iron nanoparticles were synthesized by solvothermal method, then were modified with iodosilan (IPTS). The nanoparticles were dispersed in a solution containing methacrylic acid (MMA, monomer), ethylene glycol dimethacrylate (EGDMA, cross linker), azobis isobutyronitrile (AIBN, initiator), malachite green (MG, template molecule), and N-iodosuccinimide (NIS, catalyst) to synthesized molecular imprinted polymers via surface initiated reversible chain transfer catalyzed polymerization (RCTP). After that, MG molecule was determined in tap water by silver dendrimer decorated silicon surface as a SERS substrate. The maximum adsorption capacity for MG was determined to be 34.6 mg/g on the molecular imprinted surfaces. The optimum adsorption time was determined as 60 min. The imprinting factor for MG on the imprinted nanomagnetic surface was found to be 3.69. It has been shown that selectivity studies with MG-like molecule (crystal blue and rosolic acid ) have been conducted and that particle surfaces are highly selective for MG. It has been observed that the reusability and selectivity of the imprinted nanoparticles have not changed after multiple adsorption-desorption cycles. The limit of detection (LOD) of MG was calculated as 0.06 pM in tap water and also MG on SERS active surfaces have been regenerated by being completely removed from the surface after 60 min. By using UV/O3. It was determined that the surfaces are resistant to UV/O3 and can be regenerated at least 10 times. Keywords: Malachite green, Nanoparticles, SERS, RCTP